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Geologic units containing sandstone

Earth material > Sedimentary rock > Clastic rock
Sandstone
A medium-grained clastic sedimentary rock composed of abundant sand-sized fragments, which may have a finer-grained matrix (silt or clay), and which is more or less indurated by a cementing material...
This category is also used for quartz sandstone.
Subtopics:
Arenite
Arkose
Wacke

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Alabama
Chattanooga Shale (Devonian)
Chattanooga Shale - Brownish-black organic shale containing light to dark-gray sandstone and rare limestone interbeds near the base.
Chattanooga Shale (Devonian)
Chattanooga Shale - Brownish-black organic shale containing light to dark-gray sandstone and rare limestone interbeds near the base.
Chattanooga Shale (Devonian)
Chattanooga Shale - Brownish-black organic shale containing light to dark-gray sandstone and rare limestone interbeds near the base.
Chattanooga Shale and Frog Mountain Sandstone undifferentiated (Devonian)
Chattanooga Shale and Frog Mountain Sandstone undifferentiated (In areas mapped as Dcfm one or both units may be locally absent) - Chattanooga Shale -- Brownish-black organic shale containing light to dark-gray sandstone and rare limestone interbeds near the base. Frog Mountain Sandstone -- light to dark-gray sandstone with thin dark-gray shale interbeds, light-gray to black dolomudstone, glauconitic limestone, and fossiliferous chert locally in lower part.
Chilhowee Group undifferentiated (Cambrian)
Chilhowee Group undifferentiated - light to medium-gray arkose, arkosic conglomerate, and discontinous mudstone overlain by greenish-gray mudstone with minor siltstone and sandstone; dominantly light-gray pebbly quartzose sandstone in upper part.
Claiborne Group; Tallahatta Formation (Eocene)
Tallahatta Formation - (Claiborne group), White to very light-greenish-gray thin-bedded to massive siliceous claystone; interbedded with thin layers of fossiliferous clay, sandy clay, and glauconitic sand and sandstone. White to light-greenish-gray fine to coarse sand and fine gravel occur at the base of the formation in southwest Alabama (Meridian Sand Member).
Colvin Mountain Sandstone (Ordovician)
Colvin Mountain Sandstone - light-gray quartzose sandstone, pebbly in part. Locally contains thin beds of bentonite in the upper part.
Eutaw Formation (Cretaceous)
Eutaw Formation - Light-greenish-gray to yellowish-gray cross-bedded, well-sorted, micaceous, fine to medium quartz sand that is fossiliferous and glauconitic in part and contains beds of greenish-gray micaceous, silty clay and medium-dark-gray carbonaceous clay. Light-gray glauconitic fossiliferous sand, thin beds of sandstone, and massive accumulations of fossil oyster shells occur locally in the upper part of the formation in western AL (Tombigbee Sand Member). In eastern AL thin to thick-bedded accumulations of the fossil oyster Ostrea cretacea Morton occur throughout much of the formation.
Floyd Shale (Mississippian)
Floyd Shale - Dark-gray shale, sideritic in part; thin beds of sandstone, limestone and chert are locally present; beds of partly bioclastic, partly argillaceous limestone are abundant in parts of Calhoun and Cherokee Counties.
Frog Mountain Sandstone (Devonian)
Frog Mountain Sandstone -- light to dark-gray sandstone with thin dark-gray shale interbeds, light-gray to black dolomudstone, glauconitic limestone, and fossiliferous chert locally in lower part.
Greensport Formation (Ordovician)
Greensport Formation - variegated dusky-red and dark-yellowish-orange shale, calcareous mudstone, limestone, siltstone, and minor sandstone.
Hartselle Sandstone (Mississippian)
Hartselle Sandstone - Light-colored thick-bedded to massive quartzose sandstone, containing interbeds of dark-gray shale.
Hartselle Sandstone (Mississippian)
Hartselle Sandstone - Light-colored thick-bedded to massive quartzose sandstone, containing interbeds of dark-gray shale.
Hartselle Sandstone (Mississippian)
Hartselle Sandstone - Light-colored thick-bedded to massive quartzose sandstone, containing interbeds of dark-gray shale.
Midway Group; Clayton Formation (Paleocene)
Clayton Formation - (Midway Group), White to yellowsih-gray argillaceous limestone occurs in the upper part (McBryde Limestone Member): the lower part is medium-gray fossiliferous calcareous silt, glauconitic sand and thin beds of sandy limestone and calcareous sandstone (Pine Barren Member). At the base of the formation in southeast AL is a gravelly medium to coarse sand containing clay pebbles. The formation thins west of Wilcox County and westward from Thomaston in eastern Marengo County is mapped with the Porters Creek Formation. The formation is generally deeply weathered and fresh exposures are rare. In western areas exposures consist of weathered white to yellowish-gray argillaceous, fossiliferous sandy limestone, ferruginous sand, and fossiliferous sandstone. In eastern areas exposures consist of residual accumulations of chert boulders, moderate-reddish-orange sand, and clay containing masses and thin layers of iron minerals (limonite-goethite).
Nichols Formation (Cambrian)
Nichols Formation - massive to laminated greenish-gray and black micaceous mudstone containing minor interbeds of siltstone and very fine-grained sandstone.
Paleozoic shale undifferentiated (Mississippian)
Paleozoic shale undifferentiated - Dark-gray shale and mudstone, locally containing thin interbeds and lenses of dark-greenish-gray sandstone includes Athens Shale and probable Floyd Shale in the structural windows near Anniston, Calhoun County.
Paleozoic shale undifferentiated (Mississippian)
Paleozoic shale undifferentiated - Dark-gray shale and mudstone, locally containing thin interbeds and lenses of dark-greenish-gray sandstone includes probable Floyd Shale in area east of Gadsden, Etowah County.
Parkwood and Pennington Formations (Pennsylvanian-Mississippian)
Parkwood and Pennington Formations undifferentiated - Interbedded medium to dark-gray shale and light to medium-gray sandstone, locally contains lithic conglomerate, dusky-red and grayish-green mudstone, argillaceous limestone, and clayey coal.
Parkwood and Pennington Formations undifferentiated (Pennsylvanian-Mississippian)
Parkwood and Pennington Formations undifferentiated - Interbedded medium to dark-gray shale and light to medium-gray sandstone, locally contains lithic conglomerate, dusky-red and grayish-green mudstone, argillaceous limestone, and clayey coal.
Parkwood Formation (Pennsylvanian-Mississippian)
Parkwood Formation - Interbedded medium to dark-gray shale and light to medium-gray sandstone; locally contains dusky-red and grayish-green mudstone, argillaceous limestone, and clayey coal.
Parkwood Formation (Pennsylvanian-Mississippian)
Parkwood Formation - Interbedded medium to dark-gray shale and light to medium-gray sandstone; locally contains dusky-red and grayish-green mudstone, argillaceous limestone, and clayey coal.
Parkwood Formation and Floyd Shale undifferentiated (Pennsylvanian-Mississippian)
Parkwood Formation and Floyd Shale undifferentiated - Parkwood Formation -- Interbedded medium to dark-gray shale and light to medium-gray sandstone; locally contains dusky-red and grayish-green mudstone, argillaceous limestone, and clayey coal. Floyd Shale -- Dark-gray shale, sideritic in part; thin beds of sandstone, limestone and chert are locally present; beds of partly bioclastic, partly argillaceous limestone are abundant in parts of Calhoun and Cherokee Counties.
Pennington Formation (Mississippian)
Pennington Formation - Medium-gray shale, containing interbedded limestone, dolomite, argillaceous sandstone, dusky-red and grayish-olive mudstone, and minor shaly coal. Mainly restricted to eastern part of Interior Low Plateaus province and where less than 100 feet thick the formation is included in the Bangor Limestone.
Pennington Formation (Mississippian)
Pennington Formation - Medium-gray shale, containing interbedded limestone, dolomite, argillaceous sandstone, dusky-red and grayish-olive mudstone, and minor shaly coal. Mainly restricted to northeastern AL and part of the Sequatchie anticline. Where less than 100 feet thick the formation is included in the Bangor Limestone.
Pottsville Formation (Pennsylvanian)
Pottsville Formation - Light-gray thin to thick-bedded quartzose sandstone and conglomerate containing interbedded dark-gray shale, siltstone, and coal. Mapped on Lookout Mountain, Blount and Chandler Mountains, and Sand Mountain northeats of Blount County, and on the mountains of Jackson, Marshall and Madison Counties north and west of the TN river.
Pottsville Formation (lower part) (Pennsylvanian)
Pottsville Formation (lower part) - Light-gray thick-bedded to massive pebbly quartzose sandstone, containing varying amounts of interbedded dark-gray shale, siltstone, and thin discontinuos coal. The Boyles Sandstone Member is a formally named unit in the lower part of the formation. Top of unit is mapped at the Black Creek coal.
Pottsville Formation (lower part) (Pennsylvanian)
Pottsville Formation (lower part) - Light-gray thick-bedded to massive pebbly quartzose sandstone, containing varying amounts of interbedded dark-gray shale, siltstone, and thin discontinuos coal. In both the Cahaba and Coosa synclinoria the members in descending order include: the Pine Sandstone Member and the Shades Sandstone Member. Top of unit is mapped at top of Pine Sandstone Member.
Pottsville Formation (upper part) (Pennsylvanian)
Pottsville Formation (upper part) - Interbedded dark-gray shale, siltstone, medium-gray sandstone, and coal in cyclic sequences. In descending order the members include: Razburg Sandstone Member, Camp Branch Sandstone Member, Lick Creek Sandstone Member, and the Bremen Sandstone Member.
Pottsville Formation (upper part) (Pennsylvanian)
Pottsville Formation (upper part) - Interbedded dark-gray shale, siltstone, medium-gray sandstone, and coal in cyclic sequences. The members present in the Cahaba synclinorium in descending order include: the Straven Conglomerate Member, Rocky Ridge Sandstone Member, and Chestnut Sandstone Member. The members present in the Coosa synclinorium in descending order include: Straight Ridge Sandstone Member and Wolf Ridge Sandstone Member.
Pride Mountain Formation (Mississippian)
Pride Mountain Formation - Medium to dark-gray shale, containing one to three units of a variable combination of sandstone and limestone in the lower part; locally contains rare interbeds of dusky-red and greenish-gray mudstone.
Pride Mountain Formation (Mississippian)
Pride Mountain Formation - Medium to dark-gray shale, containing one to three units of a variable combination of sandstone and limestone in the lower part; locally contains rare interbeds of dusky-red and greenish-gray mudstone.
Pride Mountain Formation (Mississippian)
Pride Mountain Formation - Medium to dark-gray shale, containing one to three units of a variable combination of sandstone and limestone in the lower part; locally contains rare interbeds of dusky-red and greenish-gray mudstone.
Red Mountain Formation (Silurian)
Red Mountain Formation - dark-reddish-brown to olive-gray partly fossiliferous, mostly fine-grained sandstone interbedded with siltstone and shale; minor amounts of bioclastic limestone and conglomerate sandstone; includes hematitic beds and beds of ferruginous sandstone, outcrops in northeastern AL are finer grained and include more limestone.
Red Mountain Formation (Silurian)
Red Mountain Formation - Interbedded yellowish-gray to moderate-red sandstone, siltstone and shale; greenish-gray to moderate-red fossiliferous partly silty and sandy limestone; few thin hematitic beds.
Red Mountain Formation (Silurian)
Red Mountain Formation - Interbedded yellowish-gray to moderate-red sandstone, siltstone and shale; greenish-gray to moderate-red fossiliferous partly silty and sandy limestone; few thin hematitic beds.
Rome Formation (Cambrian)
Rome Formation - variegated thinly interbedded mudstone, shale, siltstone, and sandstone; limestone and dolomite occur locally. Quartzose sandstone commonly present near top of formation.
Selma Group; Blufftown Formation (Cretaceous)
Blufftown Formation - (Selma Group), The Blufftown extends from the Chattahoochee River Valley westward into central Russell County where it is divided into two westward-extending tongues by an eastward-extending tongue of the Mooreville Chalk. In the Chattahoochee River Valley the Blufftown is mainly glauconitic calcareous fine sand, micaceous clay and marl, fossiliferous clay, gray calcareous fossiliferous sandstone, and carbonaceous clay and silt. To the west the lower tongue of the Blufftown is gravelly sand, glauconitic sand, calcareous clay, and sandy clay and merges with the lower part of the Mooreville Chalk in southwestern Macon County. The upper tongue is mainly calcareous sandy clay and micaceous silty fine sand with thin layers of limestone and sandstone. The upper tongue merges with the Mooreville Chalk and the lower part of the Demopolis Chalk in western Bullock County.
Selma Group; Ripley Formation (Cretaceous)
Ripley Formation - (Selma Group), Light-gray to pale-olive massive, micaceous, glauconitic, fossiliferous fine sand; sandy calcareous clay; and thin indurated beds of fossiliferous sandstone.
Sequatchie Formation (Ordovician)
Sequatchie Formation - dusky-red to light-olive-gray siltstone, sandstone, shale, and dolomite, regular but uneven bedding.
Sequatchie Formation, Colvin Mountain Sandstone, Greensport Formation undifferentiated (Ordovician)
Sequatchie Formation, Colvin Mountain Sandstone, Greensport Formation undifferentiated - variegated dusky-red and pale-yellowish-orange shale, calcareous mudstone, dolomite, siltstone, and minor sandstone. Mapped in areas of facies transition with the Chickamauga Limestone (Scraper Mountain) and in the structurally complex area at the east end of Dry Creek Mountain.
Sequatchie Formation, Colvin Mountain Sandstone, Greensport Formation undifferentiated (Ordovician)
Sequatchie Formation, Colvin Mountain Sandstone, Greensport Formation undifferentiated - variegated dusky-red and pale-yellowish-orange shale, calcareous mudstone, dolomite, siltstone, and minor sandstone. Mapped in areas of facies transition with the Chickamauga Limestone (Canoe Creek, Dunaway, and Hensley Mountains).
Talladega Group; Butting Ram Sandstone (Silurian?-Devonian)
Butting Ram Sandstone - white to light-bluish-gray medium to coarse-grained, locally conglomeratic thick-bedded quartzose sandstone. Possible Devonian fossils.
Tuscaloosa Group undifferentiated (Cretaceous)
Tuscaloosa Group undifferentiated - Light-gray to moderate-reddish-orange clayey, gravelly fine to very coarse sand; massive mottled sandy clay; local wood and leaf beds; and thin beds of indurated sandstone. Gravel consists mainly of quartz and quartzite and range in size from very fine pebbles to large cobbles. Mapped eats of the Tallapoosa River.
Weisner and Wilson Ridge Formations undifferentiated (Cambrian)
Weisner and Wilson Ridge Formations undifferentiated -- interbedded quartzose to slightly feldspathic sandstone and laterally continous conglomerate in ledge-forming units separated by greenish-gray silty mudstone.
Wilcox Group; Hatchetigbee Formation (Eocene)
Hatchetigbee Formation - (Wilcox Group), Light to dark-gray laminated carbonaceous clay, silt and very fine to fine sand, and cross-bedded glauconitic sand; one or more thin beds of fossiliferous marly glauconitic sand and sandstone occur in the upper part. Near the base is a prominent bed of glauconitic calcareous sand containing abundant fossils and spheroidal to pillow-shaped sandstone concretions (Bashi Marl Member). In parts of southeast AL the upper beds of the Th were either eroded or not deposited and the overlying Tt formation directly overlies the Bashi Marl Member.
Wilcox Group; Tuscahoma Sand (Paleocene)
Tuscahoma Sand - (Wilcox Group), Light-gray to light-olive-gray laminated and thin-bedded carbonaceous silt and clay interbedded with fine sand; thin lignite beds occur locally. Lower part of the formation includes beds of fossiliferous, glauconitic fine quartz sand containing speroidal sandstone concretions, gravel and clay pebbles.
Arkansas
Arkadelphia Marl (Phanerozoic | Mesozoic | Cretaceous-Late)
Arkadelphia Marl
Atoka Formation - Lower part (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Atokan])
Atoka Formation - Lower part
Atoka Formation - Middle part (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Atokan])
Atoka Formation - Middle part
Atoka Formation, undivided (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Atokan] )
Atoka Formation, undivided
Atoka Formation - Upper part (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Atokan])
Atoka Formation - Upper part
Blakely Sandstone (Middle and Lower Ordovician) (Phanerozoic | Paleozoic | Ordovician-Early Ordovician-Middle)
Blakely Sandstone (Middle and Lower Ordovician)
Bloyd Shale, and Prairie Grove Member of the Hale Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Morrowan])
Bloyd Shale, and Prairie Grove Member of the Hale Formation
Boggy Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Des Moinesian])
Boggy Formation
Cane Hill Member of Hale Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early [Morrowan])
Cane Hill Member of Hale Formation
Cason Shale and Fernvale Limestone (Upper Ordovician) and Kimmswick Limestone, Plattin Limestone, and Joachim Dolomite (Middle Ordovician) (Phanerozoic | Paleozoic | Ordovician-Middle Ordovician-Late)
Cason Shale and Fernvale Limestone (Upper Ordovician) and Kimmswick Limestone, Plattin Limestone, and Joachim Dolomite (Middle Ordovician)
Chattanooga Shale (Lower Mississippian and Upper Devonian), Clifty Limestone (Middle Devonian), and Penters Chert (Lower Devonian) (Phanerozoic | Paleozoic | Devonian-Early Devonian-Middle(?) Devonian-Late(?) Carboniferous Mississippian-Early)
Chattanooga Shale (Lower Mississippian and Upper Devonian), Clifty Limestone (Middle Devonian), and Penters Chert (Lower Devonian)
Cotter and Jefferson City Dolomites (Phanerozoic | Paleozoic | Ordovician-Early)
Cotter and Jefferson City Dolomites
Crystal Mountain Sandstone (Phanerozoic | Paleozoic | Ordovician-Early)
Crystal Mountain Sandstone
Harthshorne Sandstone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Des Moinesian])
Harthshorne Sandstone
Jackfork Sandstone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early [Morrowan])
Jackfork Sandstone
Johns Valley Shale (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early [Morrowan])
Johns Valley Shale
Mazarn Shale (Phanerozoic | Paleozoic | Ordovician-Early)
Mazarn Shale
McAlester Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Des Moinesian])
McAlester Formation
Midway Group (Phanerozoic | Cenozoic | Tertiary | Paleocene)
Midway Group
Missouri Mountain Shale and Baylock Sandstone (Phanerozoic | Paleozoic | Silurian)
Missouri Mountain Shale and Baylock Sandstone - The Baylock Sandstone is present only in the Cross, Cossatot, and Trap Mountains. Missouri Mountain Shale is mapped with Polk Creek Shale and Bigfork Chert in the area between Paron, Saline County, and Little Rock
Pitkin Limestone, Fayetteville Shale (including the Wedington Sandstone member), and Batesville Sandstone (including the Hindsville Limestone Member) (Phanerozoic | Paleozoic | Carboniferous Mississippian-Late [Chesterian])
Pitkin Limestone, Fayetteville Shale (including the Wedington Sandstone member), and Batesville Sandstone (including the Hindsville Limestone Member)
Powell Dolomite (Phanerozoic | Paleozoic | Ordovician-Early)
Powell Dolomite
Savanna Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Des Moinesian])
Savanna Formation
Stanley Shale (Phanerozoic | Paleozoic | Carboniferous Mississippian-Early)
Stanley Shale - Includes Chickasaw Creek Chert equivalent of Harlton (1938) near top and Hatton Tuff Lentil and Hot Springs Sandstone Member near base
St. Peter Sanstone and Everton Formation (Middle Ordovician) (Phanerozoic | Paleozoic | Ordovician-Middle)
St. Peter Sanstone and Everton Formation (Middle Ordovician)
Womble Shale (Middle Ordovician) (Phanerozoic | Paleozoic | Ordovician-Middle)
Womble Shale (Middle Ordovician)
Woodbine Formation (Phanerozoic | Mesozoic | Cretaceous-Late)
Woodbine Formation
Arizona
Chinle Formation (Late Triassic)
Colorful mudstone, such as in the Painted Desert, and less abundant lenses of sandstone and conglomerate, deposited by a large river system. This unit typically is eroded into badlands topography and contains clays that are prone to shrinking and swelling. (210-230 Ma)
Cretaceous sedimentary rocks (Cretaceous)
Tan sandstone (Dakota Sandstone) overlain by gray shale (Mancos Shale); deposited in beach, river delta, and shallow sea settings. The Mancos Shale is overlain by the Mesaverde Group (map unit Kmv). This unit includes related sandstone and shale exposed near Show Low, Morenci (Pinkard Formation), and around Deer Creek south of Globe. (about 88-97 Ma)
Cretaceous to Late Jurassic sedimentary rocks with minor volcanic rocks (Late Jurassic to Cretaceous)
Sandstone and conglomerate, rarely forms prominent outcrops; massive conglomerate is typical near base of unit and locally in upper part. These deposits are nonmarine except in southeastern Arizona, where prominent gray marine limestone (Mural Limestone) forms the middle of the Bisbee Group. Sandstones are typically medium-bedded, drab brown, lithic-feldspathic arenites. Includes Bisbee Group (largely Early Cretaceous) and related rocks, Temporal, Bathtub, and Sand Wells formations, rocks of Gu Achi, McCoy Mountains Formation, and Upper Cretaceous Fort Crittenden Formation and equivalent rocks. (80-160 Ma)
Early Proterozoic metasedimentary rocks (Early Proterozoic)
Metasedimentary rocks, mostly derived from sandstone and shale, with minor conglomerate and carbonate rock. Includes quartz-rich, mostly nonvolcanic Pinal Schist in southeastern Arizona and variably volcanic-lithic sedimentary rocks in the Yavapai and Tonto Basin supergroups in central Arizona. (1600-1800 Ma)
Early Proterozoic metavolcanic rocks (Early Proterozoic)
Weakly to strongly metamorphosed volcanic rocks. Protoliths include basalt, andesite, dacite, and rhyolite deposited as lava or tuff, related sedimentary rock, and shallow intrusive rock. These rocks, widely exposed in several belts in central Arizona, include metavolcanic rocks in the Yavapai and Tonto Basin supergroups. (1650 to 1800 Ma)
Glen Canyon Group (Early Jurassic)
Conspicuous red, cross-bedded Wingate Sandstone and the conspicuously cross-bedded, eolian, red to buff Navajo Sandstone form prominent cliffs in northern Arizona. These two sandstone units are separated by variably colored siltstone, silty sandstone, and sandstone of the Kayenta and Moenave Formations. (180-210 Ma)
Holocene to middle Pliocene basaltic rocks (Middle Pliocene to Holocene)
Mostly dark-colored basaltic lava and cinders young enough that some original volcanic landforms are still apparent. Includes a small amount of andesite, dacite, and rhyolite. Rocks of this map unit are largely restricted to six areas widely distributed in Arizona: San Francisco and Uinkaret volcanic fields in northern Arizona (0-4 Ma); Springerville (0-4 Ma) and San Carlos (0-2 Ma) volcanic fields in east-central Arizona; and San Bernardino (0-1 Ma) and Sentinel (1-4 Ma) volcanic fields in southern Arizona. Rocks of this unit are also present in the extreme southwestern part of Arizona where they were erupted at the edge of the Pinacate volcanic field (0-2 Ma) in northwestern Sonora. (0-4 Ma)
Jurassic and Triassic sedimentary and volcanic rocks (Triassic and Jurassic)
Undivided massive quartz-feldspar porphyry of the Jurassic Planet Volcanics, quartz-rich metasandstone of the Jurassic Vampire Formation, and quartzite, phyllite, and fine grained, variably calcareous metasiltstone of the Triassic Buckskin Formation; exposed primarily in the Buckskin and Rawhide Mountains of western Arizona. This unit also includes sandstone and conglomerate beneath Jurassic volcanic rocks in the central Dome Rock Mountains. (160-240 Ma)
Jurassic sedimentary and volcanic rocks (Jurassic)
Sandstone and conglomerate derived from volcanic rocks with associated intermediate-composition lava flows, breccias, and tuffs. In southern Arizona this unit includes rocks of the Artesa sequence, Pitoikam Formation, Mulberry Wash volcanics, Rudolfo Red Beds, Recreation Red Beds, and Gardner Canyon Formation. In western Arizona it includes the Harquar Formation, rocks of Slumgullion, and related(?) unnamed units in the Kofa and Middle Mountains. This unit is characterized by maroon, brown, and purplish-gray volcanic-lithic sandstone and siltstone, with subordinate to abundant conglomerate, quartz-rich sandstone and sparse limestone. (150-170 Ma)
Jurassic to Cambrian metamorphosed sedimentary rocks (Cambrian to Jurassic)
Highly faulted and folded rocks of units Jv, J_, and Pz, deformed and metamorphosed in Jurassic, Cretaceous and Tertiary time. This unit is restricted to west-central Arizona. (160-540 Ma)
Jurassic volcanic rocks (Jurassic)
Massive quartz-feldspar porphyry, generally interpreted as thick, welded rhyolitic tuffs, with locally abundant lava, and sandstone and conglomerate derived from volcanic rocks. Rare eolian quartzite units are interbedded in southern Arizona. Includes Ali Molina Formation, Mount Wrightson Formation, part of the Canelo Hills Volcanics, Cobre Ridge tuff, Black Rock volcanics, Planet Volcanics, and equivalent rocks. (160-200 Ma)
Late to middle Miocene basaltic rocks (Middle to Late Miocene)
Mostly dark, mesa-forming basalt deposited as lava flows. Rocks of this unit are widely exposed south of Camp Verde (Hickey Formation basalts), in the Mohon Mountains north of Bagdad, "The Mesa" east of Parker, and at other scattered locations in western Arizona. Rocks of this unit were not tilted by middle-Tertiary normal faulting except in a narrow belt from north of Phoenix to the northwest corner of the state. (8-16 Ma)
Middle Miocene to Oligocene sedimentary rocks (Oligocene to Middle Miocene)
Con-glomerate, sandstone, mudstone, limestone, and rock-avalanche breccia (sheet-like deposits of crushed rock) deposited and tilted during widespread normal faulting and basin development. Sediments, mostly conglomerate and sandstone, are commonly medium to dark brown, reddish brown, or brownish gray; younger strata are generally lighter colors. Most deposits are 20 to 30 Ma in southeastern Arizona and 15 to 25 Ma in central and western Arizona. (11-32 Ma)
Middle Miocene to Oligocene shallow intrusions (Oligocene to Middle Miocene)
Generally very fine-grained, porphyritic rhyolite to dacite in small, irregular-shaped bodies formed as subvolcanic intrusions in volcanic fields of southern and western Arizona, or in concentrated zones of dikes in the Mohave and Black Mountains of northwestern Arizona. The unit consists of mafic tuff, breccia and shallow intrusions at Buell Park in northeastern Arizona. (14-35 Ma)
Middle Miocene to Oligocene volcanic and sedimentary rocks, undivided (Oligocene to Middle Miocene)
Sequences of diverse volcanic rocks with abundant interbedded sedimentary rocks. (11-32 Ma)
Middle Miocene to Oligocene volcanic rocks (Oligocene to Middle Miocene)
Lava, tuff, fine-grained intrusive rock, and diverse pyroclastic rocks. These compositionally variable volcanic rocks include basalt, andesite, dacite, and rhyolite. Thick felsic volcanic sequences form prominent cliffs and range fronts in the Black (Mohave County), Superstition, Kofa, Eagletail, Galiuro, and Chiricahua Mountains. This unit includes regionally extensive ash-flow tuffs, such as the Peach Springs tuff of northwestern Arizona and the Apache Leap tuff east of Phoenix. Most volcanic rocks are 20-30 Ma in southeastern Arizona and 15 to 25 Ma in central and western Arizona, but this unit includes some late Eocene rocks near the New Mexico border in east-central Arizona. (11-38 Ma)
Middle Proterozoic sedimentary rocks (Middle Proterozoic)
Red-brown shale and sandstone, buff to orange quartzite, limestone, basalt, black shale, and sparse conglomerate. This unit includes the Grand Canyon Supergroup, Apache Group, and Troy Quartzite. These rocks were deposited in shallow marine, coastal nonmarine, and fluvial settings. (700-1300)
Mississippian, Devonian, and Cambrian sedimentary rocks (Cambrian, Devonian, and Mississippian)
Brown to dark gray sandstone grades upward into green and gray shale, overlain by light to medium gray or tan limestone and dolostone. This unit includes the Tapeats Sandstone, Bright Angel Shale, Muav Limestone, Temple Butte Formation and Redwall Limestone in northern Arizona, and the Bolsa Quartzite, Abrigo Formation, Martin Formation, and Escabrosa Limestone in southern Arizona. These rocks record intermittent sea-level rise and inundation in early Paleozoic time. (330-540 Ma)
Moenkopi Formation (Early and Middle(?) Triassic)
Dark red sandstone and mudstone; includes gypsum beds in northwestern Arizona; deposited on a low-relief coastal plain. (230-245 Ma)
Morrison Formation (Late Jurassic)
Commonly cliff-forming, cross-bedded sandstone lenses alternating with slope-forming siltstone, mudstone and shale. Colors are highly variable, and include greenish gray, reddish brown, pink, white, and purple. Sands were deposited by braided streams with finer sediment representing overbank or lacustrine deposits. (145-160 Ma)
Oligocene to Paleocene[?] sedimentary rocks (Paleocene(?) to Oligocene)
Light colored, weakly to moderately consolidated conglomerate and sandstone deposited largely or entirely before mid-Tertiary volcanism and extensional faulting. Most sediment was deposited by early Cenozoic streams that flowed northeastward onto the Colorado Plateau from areas to the southwest that are now lower in elevation than the Plateau. Sediments of this map unit, other than the Chuska Sandstone in northeasternmost Arizona, are commonly referred to as "rim gravels" because they now rest on or near the Mogollon Rim, which is the southwestern edge of the Colorado Plateau. (30-65 Ma)
Paleozoic sedimentary rocks (Paleozoic)
Undivided Paleozoic limestone, dolostone, quartzite, shale, and related sedimentary rocks. (248-544 Ma)
Permian sedimentary rocks (Permian)
Gray to tan, cherty limestone of Kaibab and Toroweap Formations, and underlying white to tan, fine-grained Coconino Sandstone. Limestone was deposited in a shallow sea, and sandstone was deposited in near-shore dunes and beach settings. (270-280 Ma)
Permian to Pennsylvanian sedimentary rocks (Pennsylvanian to Permian)
Interbedded sandstone, shale, and limestone usually characterized by ledgy outcrops. Orange to reddish sandstone forms cliffs near Sedona. This unit includes Supai Group and Hermit Shale in northern Arizona and Naco Group in southern Arizona. It was deposited in coastal-plain to shallow-marine settings during time of variable and changing sea level. Rocks of this map unit in southern Arizona may be in part equivalent to Permian rocks of map unit P in central and northern Arizona. (280-310 Ma)
Pliocene to late Miocene basaltic rocks (Late Miocene to Pliocene)
Mostly dark, inconspicuously flat, low-lying or mesa-forming basalt deposited as lava flows. Rocks included in this unit are located almost entirely in the large volcanic fields south and west of Flagstaff, in smaller fields in northwesternmost Arizona, and in the Hopi Buttes volcanic field on the Navajo and Hopi Indian Reservations north of Holbrook. Original volcanic landforms have been obscured by erosion. (4-8 Ma)
Pliocene to middle Miocene deposits (Middle Miocene to Pliocene)
Moderately to strongly consolidated conglomerate and sandstone deposited in basins during and after late Tertiary faulting. Includes lesser amounts of mudstone, siltstone, limestone, and gypsum. These deposits are generally light gray or tan. They commonly form high rounded hills and ridges in modern basins, and locally form prominent bluffs. Deposits of this unit are widely exposed in the dissected basins of southeastern and central Arizona. (2-16 Ma)
Pliocene to middle Miocene volcanic rocks (Middle Miocene to Pliocene)
Rhyolite to andesite deposited as lava flows and related rocks associated with basaltic rocks of map units Tby and Tb. (2-12 Ma)
San Rafael Group (Middle to Late Jurassic)
Commonly cross-bedded, ledge-forming sandstone and slope-forming siltstone. Rock typically has a striped red and white aspect. The Carmel Formation and Entrada Sandstone are prominent members of this group. (Late to Middle Jurassic, about 160-180 Ma)
Sedimentary rocks of the Late Cretaceous Mesaverde Group (Late Cretaceous)
Gray to buff sandstone with interbedded shale and coal. These rocks, which are similar to slightly younger rocks that form Mesa Verde in southwestern Colorado, were deposited on the margin of a shallow sea. Rocks of this map unit host the only large coal deposits in Arizona. (84-88 Ma)
Shinarump Conglomerate Member, Chinle Formation (Late Triassic)
Basal conglomerate and pebbly sandstone of the Chinle Formation is relatively resistant to erosion and forms extensive benches in some parts of the Colorado Plateau. (210-230 Ma)
California
Cambrian marine rocks (Late Proterozoic to Middle Devonian)
Sandstone, shale, limestone, dolomite, chert, quartzite, and phyllite; includes some rocks that are possibly Precambrian
Carboniferous marine rocks, unit 2 (SE California Carbonate Assemblage) (Mississippian to Early Permian)
Shale, sandstone, conglomerate, limestone, dolomite, chert, hornfels, marble, quartzite; in part pyroclastic rocks
Carboniferous marine rocks, unit 4 (Eastern Klamath Mountains) (Mississippian to Early Permian)
Shale, sandstone, conglomerate, limestone, dolomite, chert, hornfels, marble, quartzite; in part pyroclastic rocks
Carboniferous marine rocks, unit 8 (Mono Lake) (Ordovician to Devonian)
Shale, sandstone, conglomerate, limestone, dolomite, chert, hornfels, marble, quartzite; in part pyroclastic rocks
Cretaceous marine rocks (in part nonmarine) (?), unit 1 (Blythe) (Middle Jurassic(?) to Late Cretaceous)
Undivided Cretaceous sandstone, shale, and conglomerate; minor nonmarine rocks in Peninsular Ranges (?)
Cretaceous marine rocks (in part nonmarine), unit 1 (Coast Ranges) (Early to Late Cretaceous)
Undivided Cretaceous sandstone, shale, and conglomerate; minor nonmarine rocks in Peninsular Ranges
Cretaceous marine rocks (in part nonmarine) (?), unit 2 (Jacumba) (Late Cretaceous(?) to Miocene(?))
Undivided Cretaceous sandstone, shale, and conglomerate; minor nonmarine rocks in Peninsular Ranges (?)
Cretaceous marine rocks (in part nonmarine), unit 2 (West Walker River) (Triassic(?) and/or Jurassic(?))
Undivided Cretaceous sandstone, shale, and conglomerate; minor nonmarine rocks in Peninsular Ranges
Cretaceous marine rocks (in part nonmarine), unit 3 (Mescal Range) (Middle Jurassic to late Early Cretaceous)
Undivided Cretaceous sandstone, shale, and conglomerate; minor nonmarine rocks in Peninsular Ranges
Devonian marine rocks, unit 1 (Death Valley) (Middle to Late Devonian)
Limestone and dolomite, sandstone and shale; in part tuffaceous
Devonian marine rocks, unit 2 (Eastern Klamath Mountains) (Devonian)
Limestone and dolomite, sandstone and shale; in part tuffaceous
Eocene and Paleocene marine rocks, undivided (Paleocene to middle Eocene)
Eocene marine rocks (Paleocene to Oligocene)
Shale, sandstone, conglomerate, and minor limestone; in part Oligocene and Paleocene.
Eocene nonmarine rocks, unit 1 (Northern and Central California) (Eocene)
Sandstone, shale, and conglomerate.
Eocene nonmarine rocks, unit 2 (Southern California) (middle to late Eocene)
Sandstone, shale, and conglomerate.
Franciscan Complex, unit 1 (Coast Ranges) (Jurassic to Cretaceous)
Franciscan complex: Cretaceous and Jurassic sandstone with smaller amounts of shale, chert, limestone, and conglomerate. Includes Franciscan melange, except where separated--see KJfm.
Jurassic marine rocks, unit 2 (Coast Ranges) (Late Jurassic to Early Cretaceous)
Shale, sandstone, minor conglomerate, chert, slate, limestone; minor pyroclastic rocks
Jurassic marine rocks, unit 5 (Northern Sierra Nevada and Eastern Klamath Mountains) (Devonian to Late Jurassic)
Shale, sandstone, minor conglomerate, chert, slate, limestone; minor pyroclastic rocks
Jurassic marine rocks, unit 6 (Mono Lake) (Ordovician(?) to Triassic(?))
Shale, sandstone, minor conglomerate, chert, slate, limestone; minor pyroclastic rocks
Lower Cretaceous marine rocks (Early Cretaceous)
Lower Cretaceous sandstone, shale, and conglomerate
Lower Cretaceous marine rocks (?) (Cretaceous (?))
Lower Cretaceous sandstone, shale, and conglomerate (?)
Mesozoic volcanic rocks, unit 2 (Western Sierra Foothills and Western Klamath Mountains) (Jurassic)
Undivided Mesozoic volcanic and metavolcanic rocks. Andesite and rhyolite flow rocks, greenstone, volcanic breccia and other pyroclastic rocks; in part strongly metamorphosed. Includes volcanic rocks of Franciscan Complex: basaltic pillow lava, diabase, greenstone, and minor pyroclastic rocks
Miocene marine rocks (Oligocene to Pliocene)
Sandstone, shale, siltstone, conglomerate and breccia; in part Pliocene and Oligocene.
Miocene marine rocks (?) (Miocene(?) or Pliocene(?))
Miocene marine rocks and Franciscan schist (Cretaceous(?) to Miocene)
Miocene nonmarine rocks (Oligocene to Pleistocene)
Sandstone, shale, conglomerate, and fanglomerate; in part Pliocene and Oligocene.
Oligocene marine rocks (Eocene to Miocene)
Sandstone, shale, and conglomerate; in part Miocene and Eocene.
Oligocene nonmarine rocks, unit 1 (Northern California) (Oligocene to Miocene)
Sandstone, shale, and conglomerate; in part Miocene and Eocene.
Oligocene nonmarine rocks, unit 2 (Central and Southern California) (middle Eocene to early Miocene)
Sandstone, shale, and conglomerate; in part Miocene and Eocene.
Paleocene marine rocks, unit 1 (Central and Southern California) (Paleocene)
Sandstone, shale, and conglomerate; mostly well consolidated
Paleocene marine rocks, unit 2 (Northern California) (Paleocene to late Eocene)
Sandstone, shale, and conglomerate; mostly well consolidated
Paleocene marine rocks, unit 3 (La Panza Range) (Late Cretaceous(?) to Eocene(?))
Sandstone, shale, and conglomerate; mostly well consolidated
Paleozoic marine rocks, undivided, unit 1 (Mojave Desert and Death Valley area) (Late Proterozoic to Jurassic)
Undivided Paleozoic metasedimentary rocks. Includes slate, sandstone, shale, chert, conglomerate, limestone, dolomite, marble, phyllite, schist, hornfels, and quartzite
Paleozoic marine rocks, undivided, unit 2 (Northern Mojave Desert and Southeastern Sierra Nevada) (Cambrian to Jurassic)
Undivided Paleozoic metasedimentary rocks. Includes slate, sandstone, shale, chert, conglomerate, limestone, dolomite, marble, phyllite, schist, hornfels, and quartzite
Paleozoic marine rocks, undivided, unit 3 (Eastern Sierra Nevada) (Late Proterozoic(?) to Mesozoic(?))
Undivided Paleozoic metasedimentary rocks. Includes slate, sandstone, shale, chert, conglomerate, limestone, dolomite, marble, phyllite, schist, hornfels, and quartzite
Paleozoic marine rocks, undivided, unit 4 (Western Sierra Nevada) (Ordovician to Triassic)
Undivided Paleozoic metasedimentary rocks. Includes slate, sandstone, shale, chert, conglomerate, limestone, dolomite, marble, phyllite, schist, hornfels, and quartzite
Paleozoic marine rocks, undivided, unit 6 (Northwestern Sierra Nevada) (Permian(?) to Jurassic(?))
Undivided Paleozoic metasedimentary rocks. Includes slate, sandstone, shale, chert, conglomerate, limestone, dolomite, marble, phyllite, schist, hornfels, and quartzite
Paleozoic marine rocks, undivided, unit 9 (Western Klamath Mountains) (Devonian to Jurassic)
Undivided Paleozoic metasedimentary rocks. Includes slate, sandstone, shale, chert, conglomerate, limestone, dolomite, marble, phyllite, schist, hornfels, and quartzite
Paleozoic metavolcanic rocks, unit 1 (Eastern Klamath Mountains) (Devonian and Permian)
Undivided Paleozoic metavolcanic rocks. Mostly flows, breccia and tuff, including greenstone, diabase, and pillow lavas; minor interbedded sedimentary rocks
Paleozoic metavolcanic rocks, unit 5 (Mono Lake) (Triassic to Jurassic)
Undivided Paleozoic metavolcanic rocks. Mostly flows, breccia and tuff, including greenstone, diabase, and pillow lavas; minor interbedded sedimentary rocks
Permian marine sedimentary rocks, unit 1 (Death Valley and Mojave Desert) (Pennsylvanian to Triassic)
Shale, conglomerate, limestone and dolomite, sandstone, slate, hornfels, quartzite; minor pyroclastic rocks
Pliocene marine rocks (Miocene to Pleistocene)
Sandstone, siltstone, shale, and conglomerate; in part Pleistocene and Miocene.
Plio-Pleistocene and Pliocene loosely consolidated deposits (Miocene to Pleistocene)
Pliocene and/or Pleistocene sandstone, shale, and gravel deposits; in part Miocene.
Precambrian rocks, undivided, unit 1 (Death Valley) (Early Proterozoic to Mesozoic)
Conglomerate, shale, sandstone, limestone, dolomite, marble, gneiss, hornfels, and quartzite; may be Paleozoic in part
pre-Cenozoic metasedimentary and metavolcanic rocks undivided (Early Proterozoic to Cretaceous)
Undivided pre-Cenozoic metasedimentary and metavolcanic rocks of great variety. Mostly slate, quartzite, hornfels, chert, phyllite, mylonite, schist, gneiss, and minor marble.
Schist of various types and ages, unit 3 (Santa Cruz Island) (Jurassic)
Schists of various types; mostly Paleozoic or Mesozoic age; some Precambrian.
Silurian and/or Ordovician marine rocks, unit 2 (Bishop) (Late Cambrian(?) to Early Permian(?))
Sandstone, shale, conglomerate, chert, slate, quartzite, hornfels, marble, dolomite, phyllite; some greenstone
Silurian and/or Ordovician marine rocks, unit 3 (Eastern Klamath Mountains) (Ordovician to Early Devonian)
Sandstone, shale, conglomerate, chert, slate, quartzite, hornfels, marble, dolomite, phyllite; some greenstone
Tertiary-Cretaceous Coastal Belt Rocks (Late Cretaceous to Pliocene)
Sandstone, shale and minor conglomerate in coastal belt of northwestern California; included by some in Franciscan Complex. Previously considered Cretaceous, but now known to contain early Tertiary microfossils in places.
Tertiary nonmarine rocks, undivided (Paleocene to Pliocene)
Undivided Tertiary sandstone, shale, conglomerate, breccia, and ancient lake deposits.
Triassic marine rocks, unit 1 (Death Valley area and Mojave Desert) (Early to Middle Triassic)
Shale, conglomerate, limestone and dolomite, sandstone, slate, hornfels, quartzite; minor pyroclastic rocks
Triassic marine rocks, unit 2 (Eastern Klamath Mountains) (Middle to Late Triassic)
Shale, conglomerate, limestone and dolomite, sandstone, slate, hornfels, quartzite; minor pyroclastic rocks
Triassic marine rocks, unit 3 (Lake Almanor) (Permian to Jurassic)
Shale, conglomerate, limestone and dolomite, sandstone, slate, hornfels, quartzite; minor pyroclastic rocks
Triassic marine rocks, unit 4 (West Walker River) (Triassic(?))
Shale, conglomerate, limestone and dolomite, sandstone, slate, hornfels, quartzite; minor pyroclastic rocks
Triassic marine rocks, unit 6 (Southern Sierra Nevada) (Late Triassic to Early Jurassic)
Shale, conglomerate, limestone and dolomite, sandstone, slate, hornfels, quartzite; minor pyroclastic rocks
Upper Cretaceous and Paleocene marine rocks, undivided (Late Cretaceous to Paleocene)
Sandstone, shale, and conglomerate
Upper Cretaceous marine rocks (?) (Cretaceous)
Upper Cretaceous sandstone, shale, and conglomerate (?)
Upper Cretaceous marine rocks, unit 1 (Upper Great Valley Sequence) (Late Cretaceous)
Upper Cretaceous sandstone, shale, and conglomerate
Upper Cretaceous marine rocks, unit 2 (Klamath Mountains) (late Early to Late Cretaceous)
Upper Cretaceous sandstone, shale, and conglomerate
Colorado
Animas Fm (Phanerozoic | Mesozoic Cenozoic | Cretaceous Tertiary)
Arkosic sandstone, shale, and conglomerate; contains abundant volcanic materials; Upper Cretaceous volcaniclastic McDermott Member at base
Arikaree Fm (Phanerozoic | Cenozoic | Tertiary)
Sandstone; contains abundant volcanically derived material
Belden Fm (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian)
Shale, limestone, and sandstone. Includes Kerber Fm in south-central
Browns Park Fm (Phanerozoic | Cenozoic | Tertiary)
Sandstone and siltstone; west of Park Range
Casper Fm and Lower part of Fountain Fm (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian Permian)
Casper Fm: sandstone
Chinle and Chugwater Fms (Phanerozoic | Mesozoic | Triassic)
Chinle And State Bridge Fms (Phanerozoic | Paleozoic Mesozoic | Permian Triassic)
Red siltstone and sandstone
Chinle Fm (Phanerozoic | Mesozoic | Triassic)
Red siltstone, sandstone, and limestone-pellet conglomerate
Chinle, Moenkopi, and Park City Fms (Phanerozoic | Paleozoic Mesozoic | Permian Triassic)
Red and gray siltstone, shale, and sandstone
Chugwater Fm (Phanerozoic | Mesozoic | Triassic)
Red sandstone, siltstone, shale, and local limestone and gypsum
Cliff House Sandstone (Phanerozoic | Mesozoic | Cretaceous)
Coalmont Fm (Phanerozoic | Cenozoic | Tertiary)
Arkosic sandstone, conglomerate, and shale; coal in lower part; in North Park
Cuchara Fm (Phanerozoic | Cenozoic | Tertiary)
Sandstone and shale
Cutler Fm (Phanerozoic | Paleozoic | Permian)
Arkosic sandstone, siltstone, and conglomerate
Dakota and Morrison Fms (Phanerozoic | Mesozoic | Jurassic Cretaceous)
Dakota, Burro Canyon, Morrison, and Junction Creek Fms (Phanerozoic | Mesozoic | Jurassic Cretaceous)
Burro Canyon is locally absent
Dakota, Burro Canyon, Morrison, and Wanakah Fms (Phanerozoic | Mesozoic | Jurassic Cretaceous)
Dakota Group and Morrison And Ralston Creek Fms at mountain front between Boulder and Colorado Springs. Dakota, Purgatoire, Morrison, and Ralston Creek Fms in Canon City area (Phanerozoic | Mesozoic | Jurassic Cretaceous)
Dakota, Morrison, and Sundance Fms (Phanerozoic | Mesozoic | Jurassic Cretaceous)
Dakota, Purgatoire, Morrison, Ralston Creek, and Entrada Fms in southeast. Dakota, Morrison, and Entrada Fms in central mountains. Dakota, Burro Canyon, Morrison, Wanakah, and Entrada Fms in Gunnison River area. Dakota, Morriso (Phanerozoic | Mesozoic | Jurassic Cretaceous)
Dakota Sandstone and Burro Canyon Fm (Phanerozoic | Mesozoic | Cretaceous)
Sandstone, shale, and conglomerate. In northwest and west-central: Lower Cretaceous. In southwest: Lower and Upper Cretaceous.
Dakota Sandstone and Purgatoire Fm (Phanerozoic | Mesozoic | Cretaceous)
Sandstone and shale
Dakota Sandstone or Group (Phanerozoic | Mesozoic | Cretaceous)
Denver and Arapahoe Fms (Phanerozoic | Mesozoic Cenozoic | Cretaceous Tertiary)
Sandstone, mudstone, claystone, and conglomerate; Denver is characterized by andesitic materials
Denver Fm or lower part of Dawson Arkose (Phanerozoic | Mesozoic Cenozoic | Cretaceous Tertiary)
Arkosic sandstone, shale, mudstone, conglomerate, and local coal beds
Dockum Group (Phanerozoic | Mesozoic | Triassic)
Red sandstone, siltstone, and local limestone
Dolores Fm (Phanerozoic | Mesozoic | Triassic)
Red siltstone, shale, sandstone, and limestone-pellet conglomerate
Dolores Fm and Cutler Fm (Phanerozoic | Paleozoic Mesozoic | Permian Triassic)
Red siltstone, sandstone, and conglomerate
Dry Union Fm (Phanerozoic | Cenozoic | Tertiary)
Siltstone, sandstone, and conglomerate. Includes Wagontongue Fm (Miocene) in South Park
Eocene prevolcanic sedimentary rocks (Phanerozoic | Cenozoic | Tertiary)
South-central: Arkosic sand and bouldery gravel of Echo Park Alluvium. Southwest: includes Telluride Conglomerate and Blanco Basin Fm (arkosic mudstone, sandstone, and conglomerate)
Fort Union Fm (Phanerozoic | Cenozoic | Tertiary)
Shale, sandstone, and local coal beds
Fountain Fm (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian Permian)
Arkosic sandstone and conglomerate
Fox Hills Sandstone (Phanerozoic | Mesozoic | Cretaceous)
Frontier Sandstone and Mowry Shale Members of Mancos Shale, and Dakota Sandstone (Phanerozoic | Mesozoic | Cretaceous)
Locally includes, at base, Burro Canyon Fm (shale and sandstone) or, in western Moffat County, Cedar Mountain Fm (conglomerate and shale)
Glen Canyon Group and Chinle Fm (Phanerozoic | Mesozoic | Triassic Jurassic)
In southwest, Glen Canyon Group consists of Navajo Sandstone, Kayenta Fm (red siltstone, shale, and sandstone) and Wingate Sandstone; Chinle is red siltstone
Glen Canyon Sandstone (Phanerozoic | Mesozoic | Triassic Jurassic)
In northwest
Green River Fm (Phanerozoic | Cenozoic | Tertiary)
Marlstone, sandstone, and oil shale
Green River Fm--Laney Member (Phanerozoic | Cenozoic | Tertiary)
Claystone, oil shale, and sandstone; in Sand Wash basin
Green River Fm--Lower Part (Phanerozoic | Cenozoic | Tertiary)
Shale, sandstone, marlstone, and limestone in Anvil Points, Garden Gulch, and Douglas Creek Members; in Piceance basin
Hermosa Fm (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian)
Arkosic sandstone, conglomerate, shale, and limestone; gypsum and salt in Paradox Member present in salt anticlines near Utah border
Huerfano Fm (Phanerozoic | Cenozoic | Tertiary)
Shale and sandstone. Includes Farisita Conglomerate in northwestern Huerfano County
Hunter Canyon Fm (Phanerozoic | Mesozoic | Cretaceous)
Sandstone and shale
Iles Fm (Phanerozoic | Mesozoic | Cretaceous)
Sandstone and shale. Trout Creek Sandstone Member at top; coal beds in upper half
Ingleside Fm and Fountain Fm (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian Permian)
Ingleside Fm: Limestone and calcareous sandstone. Fountain Fm: arkosic sandstone and conglomerate
Jelm, Lykins, Lyons, and Satanka Fms (Phanerozoic | Paleozoic Mesozoic | Permian Triassic)
Red siltstone, shale, and sandstone
Kayenta Fm, Wingate Sandstone, and Chinle Fm (Phanerozoic | Mesozoic | Triassic)
Kayenta Fm: red siltstone, shale, and sandstone. Chinle Fm: red siltstone and sandstone
Kirtland Shale and Fruitland Fm (Phanerozoic | Mesozoic | Cretaceous)
Shale, sandstone, and major coal beds
Lance Fm (Phanerozoic | Mesozoic | Cretaceous)
Shale, sandstone, and minor coal beds; Fox Hills equivalent at base
Laramie Fm (Phanerozoic | Mesozoic | Cretaceous)
Shale, claystone, sandstone, and major coal beds
Laramie Fm and Fox Hills Sandstone (Phanerozoic | Mesozoic | Cretaceous)
Leadville, Gilman, Dyer, Parting, and Sawatch Fms in west-central and south-central. Leadville Limestone, Ouray Limestone, Elbert Fm, and Ignacio Quartzite in far southwest (Phanerozoic | Paleozoic | Cambrian Ordovician(?) Silurian(?) Devonian(?) Carboniferous)
Elbert Fm: shale and sandstone.
Leadville Limestone, Gilman Sandstone, Dyer Dolomite, and Parting Fm (Phanerozoic | Paleozoic | Ordovician Silurian(?) Devonian)
Parting Fm: quartzite and shale.
Leadville Limestone, Williams Canyon Limestone, and one or more of: Fremont Limestone, Harding Sandstone, and Manitou Limestone (Phanerozoic | Paleozoic | Ordovician Silurian(?) Devonian(?) Carboniferous Mississippia)
Lodore Fm (Phanerozoic | Paleozoic | Cambrian)
Sandstone, shale, and conglomerate
lower part of Green River Fm and Wasatch Fm (Phanerozoic | Cenozoic | Tertiary)
Shale and sandstone
Lykins Fm and Lyons Sandstone (Phanerozoic | Paleozoic Mesozoic | Permian Triassic)
Lykins Lyons and Fountain Fms (Phanerozoic | Paleozoic Mesozoic | Carboniferous Pennsylvanian Permian(?) Triassic)
Red siltstone, sandstone, and conglomerate
Madison Limestone (Phanerozoic | Paleozoic | Carboniferous Mississippian)
Upper part includes equivalents of Upper Mississippian Doughnut and Humbug Fms (shale, limestone, and sandstone)
Madison Limestone and Lodore Fm (Phanerozoic | Paleozoic | Cambrian Ordovician(?) Silurian(?) Devonian(?) Carboniferous)
Mancos Shale (Phanerozoic | Mesozoic | Cretaceous)
Intertongues complexly with units overlying Mesaverde Group or Formation; lower part consists of a calcareous Niobrara equivalent and Frontier Sandstone and Mowry Shale Members; in areas where the Frontier and Mowry Members (Kmfm), or these and the Dakota Sandstone (Kfd) are distinguished, map unit (Km) consists of shale above Frontier Member
Mancos Shale--Frontier Sandstone and Mowry Shale Members (Phanerozoic | Mesozoic | Cretaceous)
Frontier Sandstone and Mowry Shale Members and intervening shale zone
Mancos Shale--Juana Lopez Member (Phanerozoic | Mesozoic | Cretaceous)
Calcareous sandstone; a thin but persistent unit distinguished only locally
Manitou Limestone and Sawatch Quartzite in Southern Front Range and Wet Mountains. One or more Ordovician Fms (Fremont Limestone, Harding Sandstone, and Manitou Dolomite), Dotsero Fm, Peerless Fm, and Sawatch Quartzite in west-ce (Phanerozoic | Paleozoic | Cambrian Ordovician)
Dotsero Fm: Dolomite, in White River plateau only. Peerless Fm: sandstone and dolomite.
Maroon Fm (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian Permian)
Arkosic sandstone, siltstone, conglomerate, and local limestone
Menefee Fm and Point Lookout Sandstone (Phanerozoic | Mesozoic | Cretaceous)
sandstone, shale, and coal; sandstone
Mesaverde Fm, undivided (Phanerozoic | Mesozoic | Cretaceous)
In northwest and west-central: Major coal beds in lower part; Rollins Sandstone Member at base in Delta, Gunnison, and Pitkin Counties. In southwest: sandstone and shale.
Mesaverde Group or Fm--Lower part (Phanerozoic | Mesozoic | Cretaceous)
Sandstone, shale, and major coal beds
Mesaverde Group or Fm--Upper part (Phanerozoic | Mesozoic | Cretaceous)
In Moffat and Rio Blanco Counties, sandstone, shale, and coal beds above Sego Sandstone. Along Grand Hogback south of Colorado River, sandstone and shale above coal-bearing sequence
Middle Park Fm exclusive of Windy Gap Member (Phanerozoic | Cenozoic | Tertiary)
Arkosic sandstone and conglomerate containing abundant volcanic materials. Arbitrary line between Middle Park and Coalmont Formations is at Continental Divide
Minturn and Belden Fms (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian)
Minturn Fm in west-central and south-central and other units (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian)
Arkosic sandstone, conglomerate, shale, and limestone. Includes Madera Fm and Sharpsdale Fm of Chronic (1958) in Sangre de Cristo Range and Gothic Fm of Langenheim (1952) in Elk Mountains. Other units of Middle Pennsylvanian age.
Moenkopi Fm (Phanerozoic | Mesozoic | Triassic)
Red siltstone, mudstone, sandstone, and local gypsum
Moenkopi Fm and Cutler Fm (Phanerozoic | Paleozoic Mesozoic | Permian Triassic)
Red siltstone and sandstone
Morgan Fm and Round Valley Limestone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian)
Morgan Fm: limestone, sandstone, and shale. In far northwest.
Morrison and Ralston Creek Fms (Phanerozoic | Mesozoic | Jurassic)
Ralston Creek Fm: Claystone, sandstone, limestone, and gypsum
Morrison, Curtis, and Entrada Fms (Phanerozoic | Mesozoic | Jurassic)
In extreme southwestern Moffat County, includes thin wedge of Carmel Fm (red siltstone and sandstone) beneath Entrada
Morrison, Curtis, Entrada, and Glen Canyon Fms (Phanerozoic | Mesozoic | Triassic Jurassic)
Curtis is absent along Grand Hogback
Morrison, Entrada, and Chinle Fms (Phanerozoic | Mesozoic | Triassic Jurassic)
Along southern Grand Hogback, Chinle is represented only by basal Gartra Sandstone Member
Morrison Fm (Phanerozoic | Mesozoic | Jurassic)
Variegated claystone, mudstone, sandstone, and local beds of limestone
Morrison Fm and Curtis Fm (Phanerozoic | Mesozoic | Jurassic)
Morrison Fm: Variegated claystone, mudstone, sandstone, and local beds of limestone. Curtis Fm: glauconitic sandstone and limestone
Morrison Fm and Entrada Sandstone (Phanerozoic | Mesozoic | Jurassic)
Morrison Fm and Junction Creek Sandstone (Phanerozoic | Mesozoic | Jurassic)
In Gunnison River area east of wedgeout of all units of Wanakah Fm (Jmw) except the Junction Creek Member
Morrison Fm and Sundance Fm (Phanerozoic | Mesozoic | Jurassic)
Sundance Fm: Sandstone, shale, claystone, and limestone
Morrison Fm and Wanakah Fm (Junction Creek Sandstone Member at or near top; Pony Express Limestone Member at base) (Phanerozoic | Mesozoic | Jurassic)
Wanakah Fm: Sandstone, shale, limestone, and local gypsum
Morrison Fm, Summerville Fm, and Entrada Sandstone (Phanerozoic | Mesozoic | Jurassic)
Summerville Fm: Shale and siltstone
Morrison, Ralston Creek, and Entrada (or Exeter) Fms (Phanerozoic | Mesozoic | Jurassic)
Morrison, Wanakah, and Entrada Fms (Phanerozoic | Mesozoic | Jurassic)
Mount Garfield Fm and Sego Sandstone (Phanerozoic | Mesozoic | Cretaceous)
Sandstone and shale; major coal beds in lower part of Mount Garfield
Nacimiento Fm (Phanerozoic | Cenozoic | Tertiary)
Shale and sandstone
North Park Fm (Phanerozoic | Cenozoic | Tertiary)
Sandstone, siltstone, and conglomerate; in North Park and Laramie basin
Ogallala Fm (Phanerozoic | Cenozoic | Tertiary)
Loose to well-cemented sand and gravel
Oligocene sedimentary rocks (Phanerozoic | Cenozoic | Tertiary)
Northwest: includes Duchesne River Fm (sandstone and shale; includes some rocks of Eocene age) and Bishop Conglomerate near Utah border. South-central: includes Florissant Lake Beds (tuffaceous shale and tuff) and Antero Fm (lime
One or more Ordovician fms (Phanerozoic | Paleozoic | Ordovician)
Fremont Limestone, Harding Sandstone, and Manitou Limestone
Park City Fm (Phanerozoic | Paleozoic | Permian)
Calcareous siltstone and sandstone
Parting, Fremont, and Harding Fms (Phanerozoic | Paleozoic | Ordovician Silurian(?) Devonian)
Pictured Cliffs Sandstone and Lewis Shale (Phanerozoic | Mesozoic | Cretaceous)
Pierre Shale--Middle unit (Phanerozoic | Mesozoic | Cretaceous)
In Boulder-Fort Collins area, contains Richard, Larimer, Rocky Ridge, Terry, and Hygiene Sandstone Members; elsewhere shale between zones of Baculites reesidei and B. scotti
Poison Canyon Fm (Phanerozoic | Cenozoic | Tertiary)
Arkosic conglomerate, sandstone, and shale
Raton Fm (Phanerozoic | Mesozoic Cenozoic | Cretaceous Tertiary)
Arkosic sandstone, siltstone, and shale; contains major coal deposits in Raton Basin
Rico and Hermosa Fms (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian)
Arkosic sandstone, conglomerate, shale, and limestone. Includes at base in some areas siltstone and shale of Molas Fm or Larsen Quartzite
Sangre de Cristo Fm (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian Permian)
Arkosic conglomerate, sandstone, and siltstone
San Jose Fm (Phanerozoic | Cenozoic | Tertiary)
Siltstone, shale, and sandstone
Santa Fe Fm (Phanerozoic | Cenozoic | Tertiary)
Siltstone, sandstone, and conglomerate
Sawatch Quartzite (Phanerozoic | Paleozoic | Cambrian)
Locally includes Peerless Fm
Sego Sandstone, Buck Tongue of Mancos Shale, and Castlegate Sandstone (Phanerozoic | Mesozoic | Cretaceous)
South Park Fm (Phanerozoic | Cenozoic | Tertiary)
Arkosic sandstone and shale, volcaniclastic conglomerate, and andesite flows and breccia
State Bridge Fm (Phanerozoic | Paleozoic Mesozoic | Permian Triassic)
Red and orange siltstone and sandstone
Triassic and Permian rocks (Phanerozoic | Paleozoic Mesozoic | Permian Triassic)
Red siltstone, shale, and sandstone. Includes various combinations of Nugget, Jelm, Popo Agie, Chugwater, Red Peak, Forelle, Satanka, and Goose Egg Fms near Wyoming border
Troublesome Fm (Phanerozoic | Cenozoic | Tertiary)
Sandstone and siltstone; in Middle Park
Uinta Fm (Phanerozoic | Cenozoic | Tertiary)
Sandstone and siltstone; in Piceance basin. Formerly Evacuation Creek Member of Green River Fm
Upper part of Dawson Arkose (Phanerozoic | Cenozoic | Tertiary)
Arkosic sandstone, conglomerate, and shale. Includes Green Mountain Conglomerate south of Golden
Upper Permian rocks, undivided (Phanerozoic | Paleozoic | Permian)
Siltstone, dolomite, and sandstone; in southeast
Vermejo Fm and Trinidad Sandstone (Phanerozoic | Mesozoic | Cretaceous)
Shale, sandstone, and major coal beds; sandstone
Wasatch Fm (Phanerozoic | Cenozoic | Tertiary)
Claystone, shale, and sandstone
Wasatch Fm--Cathedral Bluffs Tongue (Phanerozoic | Cenozoic | Tertiary)
Claystone, mudstone, and sandstone; in Sand Wash basin
Wasatch Fm (including Fort Union equivalent at base) and Ohio Creek Fm (Phanerozoic | Cenozoic | Tertiary)
Claystone, mudstone, sandstone, and conglomerate
Wasatch Fm--Niland Tongue (Phanerozoic | Cenozoic | Tertiary)
Mudstone, sandstone, and carbonaceous shale; in Sand Wash basin
Weber Sandstone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian Permian)
Weber Sandstone and Maroon Fm (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian Permian)
White River Fm or Group (Phanerozoic | Cenozoic | Tertiary)
East: Ashy claystone and sandstone. Includes Castle Rock Conglomerate in region southeast of Denver. Northwest: Ashy claystone in North Park
Williams Fork Fm (Phanerozoic | Mesozoic | Cretaceous)
Sandstone, shale, and major coal beds
Wingate Sandstone and Chinle Fm (Phanerozoic | Mesozoic | Triassic)
Connecticut
East Berlin Formation (Lower Jurassic)
East Berlin Formation - Maroon siltstone, silty and sandy shale, and fine-grained silty sandstone, generally well laminated and commonly well indurated, alternating with dark fissile shale; dolomitic carbonate common in cement, concretions, and thin argillaceous laminae. Local arkose; grades eastward into coarse conglomerate close to eastern border fault. The East Berlin Formation of the Hartford basin contains eight facies: trough cross-bedded sandstones, horizontally stratified sandstones, interbedded sandstones and mudrocks, ripple cross-laminated siltstones, black shales, stratified mudrocks, disrupted shales, and disrupted mudstones. These facies are interpreted as a continental depositional system and are divided into two assemblages. Sandflat/alluvial plain facies assemblage (sandstones and siltstones) is composed of sheet-flood deposits. The lacustrine assemblage (shales and mudrocks) represents a saline lake-playa system (Gierlowski-Kordesch and Rust, 1994).
New Haven Arkose (Upper Triassic; possibly Lower Jurassic at top)
New Haven Arkose - Red, pink, and gray coarse-grained, locally conglomeratic, poorly sorted and indurated arkose, interbedded with brick-red micaceous, locally shaly siltstone and fine-grained feldspathic clayey sandstone.
New Haven Arkose plus Buttress Dolerite (Upper Triassic; possibly Lower Jurassic at top plus Middle? Jurassic)
New Haven Arkose plus Buttress Dolerite - New Haven Arkose - Red, pink, and gray coarse-grained, locally conglomeratic, poorly sorted and indurated arkose, interbedded with brick-red micaceous, locally shaly siltstone and fine-grained feldspathic clayey sandstone. Buttress Dolerite (Middle? Jurassic) - Dark-gray to greenish-gray (weathers brown or gray), medium- to fine-grained, commonly porphyritic, generally massive with well-developed columnar jointing, grading from basalt near contacts to fine-grained gabbro in the interior, composed of plagioclase and pyroxene with accessory opaques and locally devitrified glass, quartz, or olivine.
Shuttle Meadow Formation (Lower Jurassic)
Shuttle Meadow Formation - Maroon to dark-gray, silty shale, siltstone, and fine-grained silty sandstone, generally well and thinly laminated. In the southern part of the State includes a layer, up to 5 m thick, of blue, commonly sandy, fine-grained limestone or dolomitic limestone, grading laterally into calcareous siltstone. Coarser and more arkosic to east and south, grading into conglomerate near the eastern border fault.
Stockbridge Marble (Lower Ordovician and Cambrian)
Stockbridge Marble (including Inwood Marble) - White to gray, massive to layered marble, generally dolomitic but containing calcite marble in upper part, locally interlayered with schist or phyllite and with calcareous siltstone or sandstone.
Unit b [of Stockbridge Marble] (Upper and Middle? Cambrian)
Unit b [of Stockbridge Marble] - White, pink, cream, and light-gray, generally well bedded dolomitic marble interlayered with phyllite and schist and with siltstone, sandstone, or quartzite, commonly dolomitic.
Unit c [of Stockbridge Marble] (Upper Cambrian)
Unit c [of Stockbridge Marble] - Gray, generally massive dolomite marble, commonly contains quartz grains, locally beds of sandstone; may be calcitic near top.
Units e and d [of Stockbridge Marble] (Lower Ordovician)
Units e and d [of Stockbridge Marble] - White to gray massive calcite marble, commonly mottled with dolomite and locally interlayered with dolomite marble and calcareous siltstone and sandstone.
Florida
Alum Bluff Group (Miocene)
Alum Bluff Group - West of the Apalachicola River, the Hawthorn Group is replaced by the Alum Bluff Group. The Alum Bluff Group includes the Chipola Formation, Oak Grove Sand, Shoal River Formation, Choctawhatchee Formation and the Jackson Bluff Formation (Huddlestun, 1984; Braunstein et al., 1988). The formations included in this group are generally defined on the basis of their molluscan faunas and stratigraphic position (Schmidt and Clark, 1980). Puri (1953) described sediment facies as they relate to the formations of the Alum Bluff Group These sediments are lithologically distinct as a group, not as individual units. Brooks (1982) mapped much of the Alum Bluff Group as the Shoal River Formation. The Alum Bluff Group crops out or is beneath a thin overburden in the western panhandle from river valleys in Okaloosa County eastward to western Jackson County. The Alum Bluff Group consists of clays, sands and shell beds which may vary from fossiliferous, sandy clays to unfossiliferous sands and clays and occasional carbonate beds (Huddlestun, 1984). Mica is a common constituent and glauconite and phosphate occur sporadically. Induration varies from essentially nonindurated in sands to well indurated in carbonate lenses. Colors range from cream to olive gray with mottled reddish brown in weathered sections. Sand grain size varies from very fine to very coarse with sporadic occurrences of gravel. These sediments generally have low permeabilities and are part of the intermediate confining unit/aquifer system.
Chattahoochee Formation (Miocene)
Chattahoochee Formation - The Chattahoochee Formation, originally named by Dall and Stanley-Brown (1894), is predominantly a yellowish gray, poorly to moderately indurated, fine-grained, often fossiliferous (molds and casts), silty to finely sandy dolostone (Huddlestun, 1988). Siliciclastic beds and limestones may be present. The Chattahoochee Formation is exposed in Jackson County, central panhandle, on the Chattahoochee "Anticline". It grades laterally across the Gulf Trough into the St. Marks Formation through a broad transition area (Scott, 1986). The Chattahoochee Formation forms the upper part of the FAS in the central panhandle.
Hawthorn Group, Peace River Formation (Miocene/Pliocene)
Hawthorne Group, Peace River Formation - The Peace River Formation crops out or is beneath a thin overburden on the southern part of the Ocala Platform extending into the Okeechobee Basin. These sediments were mapped from Hillsborough County southward to Charlotte County. Within this area, the Peace River Formation is composed of interbedded sands, clays and carbonates. The sands are generally light gray to olive gray, poorly consolidated, clayey, variably dolomitic, very fine to medium grained and phosphatic. The clays are yellowish gray to olive gray, poorly to moderately consolidated, sandy, silty, phosphatic and dolomitic. The carbonates are usually dolostone in the outcrop area. The dolostones are light gray to yellowish gray, poorly to well indurated, variably sandy and clayey, and phosphatic. Opaline chert is often found in these sediments. The phosphate content of the Peace River Formation sands is frequently high enough to be economically mined. Fossil mollusks occur as reworked casts, molds, and limited original shell material. Silicified corals and wood, and vertebrate fossils are also present. The Peace River Formation is widespread in southern Florida. It is part of the intermediate confining unit/aquifer system.
Hawthorn Group, Statenville Formation (Miocene)
Hawthorn Group, Statenville Formation - The Statenville Formation occurs at or near the surface in a limited area of Hamilton, Columbia and Baker Counties on the northeastern flank of the Ocala Platform. The formation consists of interbedded sands, clays and dolostones with common to very abundant phosphate grains. The sands predominate and are light gray to light olive gray, poorly indurated, phosphatic, fine to coarse grained with scattered gravel and with minor occurrences of fossils. Clays are yellowish gray to olive gray, poorly consolidated, variably sandy and phosphatic, and variably dolomitic. The dolostones, which occur as thin beds, are yellowish gray to light orange, poorly to well indurated, sandy, clayey and phosphatic with scattered mollusk molds and casts. Phosphate occurs in the Statenville Formation in economically important amounts. Silicified fossils and opalized claystones are found in the Statenville Formation. Permeability of these sediments is generally low, forming part of the intermediate confining unit/aquifer system.
Hawthorn Group, Torreya Formation (Miocene)
Hawthorn Group, Torreya Formation - Torreya Formation - The Torreya Formation is exposed or near the surface from western Gadsden County eastward to western-most Hamilton County. It is informally subdivided into a lower carbonate unit and an upper siliciclastic unit (Scott, 1988). The majority of Torreya Formation outcrops expose the siliciclastic part of the unit. The carbonate sediments are white to light olive gray, generally poorly indurated, variably sandy and clayey, fossiliferous (molds and casts) limestone (mudstone and wackestone). The limestones often grade into calcareous-cemented sands. Phosphate is present in the carbonate sediments, particularly in the Sopchoppy Member. The siliciclastics vary from white to light olive gray, unconsolidated to poorly indurated, slightly clayey sands with minor phosphate to light gray to bluish gray, poorly consolidated, variably silty clay (Dogtown Member). The siliciclastics are sporadically fossiliferous. The Torreya Formation overlies the FAS and forms part of the intermediate confining unit/aquifer system.
Miami Limestone (Pleistocene)
Miami Limestone - The Miami Limestone (formerly the Miami Oolite), named by Sanford (1909), occurs at or near the surface in southeastern peninsular Florida from Palm Beach County to Dade and Monroe Counties. It forms the Atlantic Coastal Ridge and extends beneath the Everglades where it is commonly covered by thin organic and freshwater sediments. The Miami Limestone occurs on the mainland and in the southern Florida Keys from Big Pine Key to the Marquesas Keys. From Big Pine Key to the mainland, the Miami Limestone is replaced by the Key Largo Limestone. To the north, in Palm Beach County, the Miami Limestone grades laterally northward into the Anastasia Formation. The Miami Limestone consists of two facies, an oolitic facies and a bryozoan facies (Hoffmeister et al. [1967]). The oolitic facies consists of white to orangish gray, poorly to moderately indurated, sandy, oolitic limestone (grainstone) with scattered concentrations of fossils. The bryozoan facies consists of white to orangish gray, poorly to well indurated, sandy, fossiliferous limestone (grainstone and packstone). Beds of quartz sand are also present as unindurated sediments and indurated limey sandstones. Fossils present include mollusks, bryozoans, and corals. Molds and casts of fossils are common. The highly porous and permeable Miami Limestone forms much of the Biscayne Aquifer of the surficial aquifer system.
Residuum on Miocene sediments (Miocene)
Residuum on Miocene sediments - The undifferentiated Miocene residuum, mapped on parts of the Chattahoochee "Anticline", characteristically consists of reddish brown, variably sandy clay with inclusions of variably fossiliferous, silicified limestone. The residuum includes Lower to Upper Miocene and younger weathered sediments.
St. Marks Formation (Miocene)
St. Marks Formation - The Lower Miocene St. Marks Formation, named by Finch (1823), is exposed in Wakulla, Leon and Jefferson Counties on the northwestern flank of the Ocala Platform. It is a white to yellowish gray, poorly to moderately indurated, sandy, fossiliferous (molds and casts) limestone (packstone to wackestone). Mollusk molds and casts are often abundant. The St. Marks Formation makes up the upper part of the FAS in part of the eastern panhandle.
Georgia
Chickamauga Group; Upper and Middle Ordovician Rocks (Omb) includes Moccasin Limestone and Bays Formation (Ordovician)
Chickamauga Group; Upper and Middle Ordovician Rocks (Omb) includes Moccasin Limestone and Bays Formation.
Chilhowee Formation (Cambrian)
Chilhowee Formation, includes Weisner Formation of Kesler, 1950
Claiborne undifferentiated (Eocene)
Claiborne undifferentiated, up-dip equivalent of Lisbon and Tallahatta Formations
Conasauga Group; Lower unit; shale and sandstone unit (Cambrian)
Conasauga Group; Lower unit; shale and sandstone unit: Includes shale and sandstone unit (Ccs) with lower dolostone unit (Ccdl). Possible equivalent of Pumpkin Valley Shale of Tennessee
Floyd Shale; Hartselle Sandstone member (Mississippian)
Hartselle Sandstone member (Mh) in Floyd County
Frog Mountain (Devonian)
Frog Mountain
Lookout Sandstone; Gizzard Formation (Pennsylvanian)
Lookout Sandstone; Gizzard Formation
Lookout Sandstone; Sewanee Sandstone (Pennsylvanian)
Lookout Sandstone; Sewanee Sandstone
Mississippian undifferentiated (Mississippian)
Mississippian undifferentiated: Includes Pennington Shale, Bangor Limestone (except in Floyd County), Hartselle Sandstone, Golconda Formation, Gasper Limestone, Ste. Genevieve Limestone and St. Louis Limestone
Neogene undifferentiated (Neogene)
Neogene undifferentiated, includes Altamaha Grit (Dall, 1892); Citronelle Formation (Matson & Berry, 1916); and "Hawthorn Formation" (Cooke, 1939). (*) - outcrops of indurated sandstone and claystone
Pennsylvanian undifferentiated (Pennsylvanian)
Pennsylvanian undifferentiated
Red Mountain Formation (Silurian)
Red Mountain Formation
Rome Formation (Cambrian)
Rome Formation
Iowa
Cherokee Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Des Moines])
Cyclic deposits with carbonaceous shale, clay, siltstone, with lesser sandstone, and thick coal beds; minor but persistent limestone beds; may include parts of Atoka or Morrow Series.
Colorado and Dakota Groups (Phanerozoic | Mesozoic | Cretaceous-Early Cretaceous-Middle(?) Cretaceous-Late)
Sandstone and shale with minor limestone; includes Carlile, Greenhorn, Graneros, and Dakota FMs. Full section present in only the extreme NW part of Iowa; in southern and easternmost areas only Dakota is present.
Cretaceous Undifferentiated (Phanerozoic | Mesozoic | Cretaceous-Early Cretaceous-Middle(?) Cretaceous-Late)
Variably calcareous, serverely deformed shales, minor sandstone and carbonate rock; in Manson anomalous area only
Ft. Dodge Beds (Phanerozoic | Mesozoic | Jurassic)
Gypsum and red and green shale; in Webster CO only
Galena-Decorah-Platteville Formations (Phanerozoic | Paleozoic | Ordovician-Middle [Mohawkian])
Galena FM- dolomite, minor limestone; chert in lower half. Approx thickness 230 ft. Decorah FM- brown limestone and dolomite; gray-green and brown shales at top and base. Approx thickness 60 ft. Platteville FM- fossiliferous gray limestone and brown dolomite; grayish-green shale at base (Glenwood). Fine- to medium-grained sandstone occurs above the Glenwood in the subsurface of southeastern Iowa. Approx thickness 110 ft
LaPort City Chert (Phanerozoic | Paleozoic | Devonian-Early)
Predominantly chert with limestone and dolomite; minor shale and sandstone. Found in subsurface only.
Marmaton Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Des Moines])
Alternating shale and limestone, with some sandstone and coal; Lenapah FM at top and Fort Scott at base.
Meramec Series (Phanerozoic | Paleozoic | Carboniferous Mississippian-Late)
Ste. Genevieve Limestone- fossiliferous limestone and red and green shale. Approx. thickness 50 ft. St. Louis Limestone- limestone and dolomite, sandstone locally perdominant; locally contains chert. Spergen Formation- sandy micaceous dolomite.
Osage Series (Phanerozoic | Paleozoic | Carboniferous Mississippian-Early)
Warsaw Formation- gray, dolomitic shale and argillaceous dolomite; chalcedonic chert. Locally contains many geodes.Approx thickness 85 ft. Keokuk Limestone- fossiliferous, gray or brown limestone and dolomite; gray and brown chert with white spicules, locally predominant in lower portion; minor brown or gray shale. Approx thickness 90 ft. Burlington Limestone- gray, fossiliferous limestone and darker gray dolomite; white and gray mottled fossiliferous chert, locally contains dolomite crystals; two widespread glauconite zones; basal sandstone locally in southeastern Iowa. Approx thickness 80 ft.
Pleasanton Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Missouri])
Shale with some sandstone, thin limestone beds and minor coal; Exline Limestone near top Chariton Conglomerate at base. .
Prairie du Chien Formation (Phanerozoic | Paleozoic | Ordovician-Early [Beekmantown])
Sandy dolomite in upper postion; sandstone in middle portion; dolomite with oolitic and tripolitic chert in lower portion.
St. Croixan Series (Phanerozoic | Paleozoic | Cambrian-Furongian)
Jordan Sandstone- fine- to medium-grained, well sorted, frosted sandstone (includes Madison Sandstone). Approx thickness 120 ft. St. Lawrence Formation- coarsely crystalline, gray, silty dolomite; glauconite common (includes Lodi Sandstone).Approx thickness 230+ ft Franconia Sandstone- glauconitic, dolomitic siltstone and shale and glauconitic sandstone. Approx thickness 280 ft Galesville Sandstone- medium- to coarse-grained, white to gray sandstone. Eau Claire Sandstone- fissile, gray, silty shale and dolomitic siltstone and fine-grained sandstone. Mt. Simon Sandstone- medium- to coarse-grained sandstone with minor shale stringers. Galesville+Eau Claire+Mt. Simon=Approx thickness 1000 ft
St. Peter Sandstone (Phanerozoic | Paleozoic | Ordovician-Early [Chazyan])
Coarse to fine, rounded, frosted sand grains; minor green shale stringers.
Wabaunsee Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Virgil])
Cyclic deposits, principally shale with limestone, siltstone, minor sandstone units and thin coal seams.
Idaho
Coralline Limestone, sandstone, siltstone, shale, chert, and phosphorite; Mississippianshallow marine inner continental-shelf deposits; east-central Idaho, central Idaho (Mississippian )
Mississippian shallow-water coralline limestone interval of southern Idaho.
Dolostone, limestone, sandstone, shale, and conglomerate; Devonian marine continental-shelf deposits; east-central and southeastern Idaho (Devonian)
Devonian bedded dolomite and limestone interval of eastern and southern Idaho.
Limestone and sandstone; Early Jurassic Cordilleran retroarc-foreland-basin deposits; southeastern Idaho (Early Jurassic)
Lower Jurassic shallow-marine to non-marine sediments; shaley, sandy limestone overlaying red, crossbedded sandstone of eastern Idaho.
Limestone, sandstone, dolostone, and chert; Permian to Pennsylvanian marine epicontinental-basin deposits; southeastern Idaho; (Early Permian to Early Pennsylvanian)
Lower Permian to Lower Pennsylvanian chert, limestone, and sandstone of southern Idaho; subdivisions are (Ps, and PNs).
Limestone, sandstone, shale, and chert; Pennsylvanian marine epicontinental-basin deposits; southeastern Idaho (Pennsylvanian)
Pennsylvanian beds; lowermost portion of the southern Idaho sequence (PPNs).
Limestone, shale, siltstone, chert, and conglomerate; Mississippian western turbiditic flysch to eastern shallow-water carbonates; east-central Idaho (Mississippian)
Mississippian shallow-water carbonate-to-clastic sequence of east-central Idaho.
Sandstone, conglomerate, siltstone, tuff, claystone, limestone, and diatomite; Pliocene tuffaceous alluvial and lacustrine deposits; Snake River Plain and vicinity, southeastern Idaho (Pliocene )
Pliocene stream and lake deposits; may be due to volcanic and block-faulting events.
Sandstone, limestone, and shale; Upper Triassic marine to non-marine epicontinental deposits; southeastern Idaho (Late Triassic)
Upper Triassic shallow-marine to non-marine sediments; oxidized shale, siltstone, limestone, and conglomeratic sandstone of eastern Idaho.
Sandstone, limestone, siltstone, shale, and conglomerate; Lower Permian to Middle Pennsylvanian deltaic turbidites; central Idaho; (Early Permian)
Lower Permian to Middle Pennsylvanian thrusted, marine detritus of central Idaho.
Sandstone, shale, siltstone, limestone, and coal; Late Cretaceous Cordilleran retroarc-foreland-basin deposits; southeastern Idaho (Late Cretaceous)
Upper Cretaceous thick detrital and fresh-water limestone beds of southeastern Idaho.
Sandstone, siltstone, shale, limestone, and coal ; Early Cretaceous Cordilleran retroarc-foreland-basin deposits; southeastern Idaho (Early Cretaceous)
Lower Cretaceous shale, siltstone, red-bed sandstone and fresh-water limestone.
Shale, conglomerate, sandstone, siltstone, limestone, and chert; Mississippian turbidite flysch from a western source; central Idaho (Mississippian)
Mississippian thrusted, shallow-to-deep marine detrital units of central Idaho.
Shale, limestone, and sandstone; Triassic marine to non-marine epicontinental deposits (subunits are TRl and TRu) (Triassic)
Triassic shallow-marine to non-marine sediments of eastern Idaho; subdivisions are (TRu and TRl).
Siltstone, evaporites, and redbeds; Late Jurassic Cordilleran retroarc-foreland-basin deposits; southeastern Idaho (Late Jurassic)
Upper Jurassic shallow-marine to non-marine sediments; glauconitic and variegated sandstone, siltstone and oolitic limestone of eastern Idaho.
Siltstone, shale, sandstone, and limestone; Jurassic Cordilleran retroarc-foreland-basin deposits (subunits are Jl and Ju); southeastern Idaho (Jurassic)
Jurassic shallow-marine to non-marine sediments of eastern Idaho; subdivisions are (Jl and Ju).
Tuffaceous shale, sandstone, conglomerate, and lignite; Eocene to Pliocene alluvial and lacustrine deposits; central and southern Idaho (Tertiary)
Tertiary continental sediments; predominantly Upper Tertiary in age; subdivisions are:(Tpd, Tmd, and Ted).
Illinois
Abbott Formation (Pennsylvanian)
Abbott Formation
Ancell Group (Ordovician)
Ancell Group
Bond Formation (Pennsylvanian)
Bond Formation
Cambrian (Cambrian)
Cambrian
Carbondale Formation (Pennsylvanian)
Carbondale Formation
Caseyville Formation (Pennsylvanian)
Caseyville
Cretaceous (Cretaceous)
Cretaceous
Lower Chesterian (Glen Dean - Renault) Series (Mississippian)
Lower Chersterian (Glen Dean - Renault) Series
Mattoon Formation (Pennsylvanian)
Mattoon Formation
Middle Devonian (Devonian)
Middle Devonian
Modesto Formation (Pennsylvanian)
Modesto Formation
Prairie du Chien Group (Ordovician)
Prairie du Chien Group
Spoon Formation (Pennsylvanian)
Spoon (includes Pa in northeast)
Tertiary - Paleocene, Eocene (Tertiary)
Tertiary - Paleocene, Eocene
Upper Chesterian (Grove Church - Tar Springs) Series (Mississippian)
Upper Chesterian (Grove Church - Tar Springs) Series
Upper Devonian (Devonian)
Upper Devonian
Upper Valmeyeran (Aux Vases, Ste. Genevieve, St. Louis) Series (Mississippian)
Upper Valmeyeran (Aux Vases, Ste. Genevieve, St. Louis) Series
Indiana
Black River and Ancell Groups (Ordovician)
Black River and Ancell Groups - Dolomite, limestone, and sandstone
Bond Formation (Pennsylvanian)
Bond Formation - Mostly shale and sandstone; also includes thin beds of limestone and coal
Buffalo Wallow Group (Mississippian)
Buffalo Wallow Group - Mostly shale and sandstone; also includes thin beds of micritic limestone. L, Leopold Limestone member
Carbondale Group (Pennsylvanian)
Carbondale Group - Mostly shale and sandstone; also includes thin beds of limestone, clay, and coal. S, Springfield Coal Member
Knox Supergroup (Cambrian-Ordovician)
Knox Supergroup - P, base of Prairie du Chien Group
Mattoon Formation (Pennsylvanian)
Mattoon Formation - Mostly shale and sandstone; also includes thin beds of coal
Mt. Simon Sandstone (Cambrian)
Mt. Simon Sandstone
Munising Group (Cambrian)
Munising Group - Shale, sandstone, limestone, and dolomite
Patoka and Shelburn Formations (Pennsylvanian)
Patoka and Shelburn Formations - Mostly shale and sandstone; also includes thin beds of limestone and coal. WF, top of West Franklin member
Raccoon Creek Group (Pennsylvanian)
Raccoon Creek Group - Mostly shale and sandstone; also includes thin beds of limestone, clay, and coal. B, Buffaloville Coal Member; LB, Lower Block Coal Member
Stephensport Group (Mississippian)
Stephensport Group - Sandstone, micritic and skeletal limestone, and shale
West Baden Group (Mississippian)
West Baden Group - Shale, sandstone, and micritic and skeletal limestone
Kansas
Carlile Shale (Phanerozoic | Mesozoic | Cretaceous-Late)
chalky shale with bentonite and thick chalk beds, dark gray fissile shale containing septarian concretions, and fine-grained sandstone.
Cherokee Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early [Desmoinesian])
Includes: Cabaniss FM (base CA) with Verdigris Limestone Member (base V) and Mineral coal bed (base MC), Krebs FM with Bluejacket Sandstone Member (base BJ) and Warner Sandstone Member (base WR).
Dakota Formation (Phanerozoic | Mesozoic | Cretaceous-Early)
White, gray, red, brown and tan kaolinitic claystone, mudstone, shale and siltstone interbedded with grayish to yellowish brown thick lenticular sandstone beds. It also contains lignite and sandstone is commonly well cemented with iron oxide and calcite.
Dockum Group (Phanerozoic | Mesozoic | Triassic)
varicolored shales and red sandstone
Douglas Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Virgilian])
Lawrence FM (base LA)- mostly gray shale and sandstone with minor red shale, coal, gray limestone and conglomerate, thickness ranges from 140ft to 250 ft. Stranger FM- five members containing sandstone, shale, and minor limestone, coal and conglomerate ranging from 100 ft. to 180 ft. thickness.
Greenhorn Limestone and Graneros Shale (Phanerozoic | Mesozoic | Cretaceous-Late)
Greenhorn FM- thin bedded gray, chalky limestone and calcareous shale. Graneros Shale- fissile, noncalcareous, gray shale locally contains sandstone and siltstone beds.
Guadalupia Series: Big Basin Formation, Day Creek Dolomite, and Whitehorse Formation (Phanerozoic | Paleozoic | Permian [Custerian Cimarronian])
Big Basin FM- red silty shale, siltstone, dolomitic siltstone and fine-grained feldspathic sandstone. Day Creek Dolomite- light gray to pink, dense, fine-grained dolomite. Whitehorse FM- mostly red beds of feldspathic sandstone with some beds of siltstone and shale and minor dolomite.
Kansas City Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Missourian])
Includes: Lane Shale,Wyandotte Limestone (base WY), Liberty Memorial Shale, Iola Limestone (base I), Chanute Shale (base CH), Dewey Limestone, Nellie Bly FM, Cherryvale FM, Dennis Limestone (base DN), Galeburg Shale, Mound Valley Limestone, Ladore Shale, Swope Limestone (base SW), Elm Branch Shale, Hertha Limestone.
Kiowa Shale and Cheyenne Sandstone (Phanerozoic | Mesozoic | Cretaceous-Early)
Kiowa Shale or FM- light -gray to black illitic shale with thin coquinoidal limestone beds at the base; sandstone lenses common. Cheyenne Sandstone- massive to crossbedded, light-gray to buff fine-grained sandstone with lenses of gray sandy shale and conglomerate.
Lansing Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Missourian])
Stanton Limestone- three limestone and two shales members, ranges from 15 to 130 ft. thick. Vilas Shale- sandy, carbonaceous gray shale with some sandstone and limestone locally, ranges from 5 to 120 ft. thick. Plattsburg Limestone- two limestone members separated by shale, ranging from 25 to 115 ft. thick.
Marmaton Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early [Desmoinesian])
Includes: Lost Branch FM, Memorial Shale, Lenapah Limestone (base LE), Nowata Shale, Altamont Limestone (base PA), Bandera Shale, Pawnee Limestone (base PA), Labette Shale and Fort Scott Limestone.
Nippewalla Group (Phanerozoic | Paleozoic | Permian [Custerian Cimarronian])
Dog Creek FM- maroon silty shale, siltstone, fine-grained feldspathic sandstone. Blaine FM- (base B) gypsum beds separated by dolomite and red shale. Flower Pot Shale -(base FL) red gypsiferous shale silty shale and minor sandstone and siltstone. Cedar Hills Sandstone- feldspathic sandstone, siltstone, and silty shale. Salt Plain FM- red flaky, silty shale and some siltstone with thick salt beds at base. Harper Sandstone with Kingman Sandstone member (base K)- red argillaceous siltstone and fine silty sandstone with a few beds of res shale and white sandstone. Stone Coral FM- dolomite, anhydrite, gypsum and salt.
Ogallala Formation (Phanerozoic | Cenozoic | Tertiary | Miocene)
massive to cross-bedded, generally arkosic sand, silt and gravel, locally cemented with calcium carbonate; also contains limestone, volcanic ash, diatomaceous marl, opaline sandstone and bentonitic clay
Pleasanton Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Missourian])
Includes: Shale Hill FM (base SH), and Hepler FM. Chiefly gray to very dark gray or yellowish gray shale with sandstone members and some limestone and coal.
Shawnee Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Virgilian])
Includes: Topeka Limestone, Calhoun Shale, Deer Creek Limestone (base DC), Tecumseh Shale, Lecompton Limestone (base LC), Kanwaka Shale, Oread Limestone with Plattsmouth Limestone Member (base PL).
Wabaunsee Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Virgilian])
Includes: Wood Siding FM, Root Shale, Stotler Limestone (base ST), Pillsbury Shale, Zeandale Limestone (base Z), Willard Shale, Emporia Limestone (base E), Auburn Shale, Bern Limestone (base BR), Scranton Shale, Howard Limestone (base H), and Severy Shale.
Kentucky
Breathitt Formation, lower part (Pennsylvanian)
Breathitt Formation, lower part; lower part which includes Livingston Conglomerate Member of Lee Formation in eastern Rockcastle County
Breathitt Formation, middle part (Pennsylvanian)
Breathitt Formation, middle part
Breathitt Formation, upper part (Pennsylvanian)
Breathitt Formation, upper part
Carbondale Formation (Middle Pennsylvanian)
Carbondale Formation
Caseyville Formation (Lower to Middle Pennsylvanian)
Caseyville Formation
Clayton and McNairy Formations, undivided (Paleocene to Upper Cretaceous)
Clayton and McNairy Formations, undivided
Corbin Sandstone Member of Lee Formation (Pennsylvanian)
Corbin Sandstone Member of Lee Formation
Jackson and Claiborne Formations, undivided (Tertiary)
Jackson and Claiborne Formations, undivided; includes some rocks of Oligocene age
Knifely Sandstone member of the Fort Payne Formation (Mississippian)
Knifely Sandstone member of the Fort Payne Formation
Lee Formation (Mississippian to Pennsylvanian )
Lee Formation
Mauzy Formation (Lower Permian)
Mauzy Formation
Monongahela and Conemaugh Formations, undivided (Pennsylvanian)
Monongahela and Conemaugh Formations, undivided
Pennington Formation and Newman Limestone (Mississippian)
Pennington Formation and Newman Limestone; includes Carter Caves Sandstone in Carter County and vicinity
Pennington Formation, Newman Limestone, Fort Payne Chert, Grainger Formation, Sunbury Shale, Berea Sandstone, and Bedford Shale, undivided; Pennington Formation locally includes sandstone tongue of Lee Formation (Devonian to Pennsylvanian)
Pennington Formation, Newman Limestone, Fort Payne Chert, Grainger Formation, Sunbury Shale, Berea Sandstone, and Bedford Shale, undivided; Pennington Formation locally includes sandstone tongue of Lee Formation
Pennington Formation (Paragon Formation), Bangor Limestone, Hartselle Formation, and Kidder Limestone Member of Monteagle Limestone, undivided (Mississippian)
Pennington Formation (Paragon Formation), Bangor Limestone, Hartselle Formation, and Kidder Limestone Member of Monteagle Limestone, undivided
Renfro and Muldraugh Members of Borden Formation and Fort Payne Formation, undivided (Mississippian)
Renfro and Muldraugh Members of Borden Formation and Fort Payne Formation, undivided
Rockcastle Sandstone Member of Lee Formation (Pennsylvanian)
Rockcastle Sandstone Member of Lee Formation
Rocks of Chesterian age, lower part (Upper Mississippian)
Rocks of Chesterian age, lower part
Rocks of Chesterian age, upper part (Upper Mississippian)
Rocks of Chesterian age, upper part
Sandstone member of the Mooretown Formation (Mississippian)
Sandstone member of the Mooretown Formation
Ste. Genevieve and St. Louis Limestones, undivided (Mississippian)
Ste. Genevieve and St. Louis Limestones, undivided; includes Salem Limestone west of Christian County
Sturgis Formation (Middle to Upper Pennsylvanian)
Sturgis Formation
Tradewater Formation (Middle Pennsylvanian)
Tradewater Formation
Wilcox Formation (Eocene)
Wilcox Formation
Wildie, Nada, Halls Gap, Holtsclaw Siltstone, Cowbell, Nancy, Kenwood Siltstone, New Providence Shale, Sunbury Shale, Berea Sandstone, and Bedford Shale, undivided; Borden Formation locally includes Renfro Member in eastern Kentucky (Devonian to Mississippian)
Wildie, Nada, Halls Gap, Holtsclaw Siltstone, Cowbell, Nancy, Kenwood Siltstone, New Providence Shale, Sunbury Shale, Berea Sandstone, and Bedford Shale, undivided; Borden Formation locally includes Renfro Member in eastern Kentucky
Louisiana
Carnahan Bayou Member (Phanerozoic | Cenozoic | Tertiary | Miocene)
yellow to gray siltstones, sandstones, and clays with thin tuffaceous beds; some lenses of black chert gravel; petrified wood locally.
Catahoula Formation (Phanerozoic | Cenozoic | Tertiary | Oligocene)
gray to white sandstones; loose quartz sand, tuffaceous sandstone, volcanic ash, and brown sandy clays; petrified wood locally. Overlain by 1-9 meters of loess.
Catahoula Formation (Phanerozoic | Cenozoic | Tertiary | Oligocene)
gray to white sandstones; loose quartz sand, tuffaceous sandstone, volcanic ash, and brown sandy clays; petrified wood locally.
Sparta Formation (Phanerozoic | Cenozoic | Tertiary | Eocene)
white to light gray massive sands with interbedded clays; some thin beds of lignite or lignitic sands and shales.
Massachusetts
Bellingham Conglomerate (Pennsylvanian, Cambrian or Proterozoic Z)
Bellingham Conglomerate - Red and gray metamorphosed conglomerate, sandstone, graywacke, and shale. Bellingham Conglomerate consists of conglomerate and lithic graywacke interbedded with chlorite phyllite and is confined to Bellingham basin. Also contains some volcanic rocks (rhyolite porphyry in roadcut on MA Hwy 146 at Premisy Hill west of Woonsocket, and felsite porphyry in the Franklin area east of Bellingham). Conglomerate contains pebbles of quartzite from adjacent Blackstone Group rocks and typical blue quartz of Milford Granite, so sediments are locally derived. Exposures on east side of Woonsocket Hill, southeast of Woonsocket, RI, show cliffs of steeply dipping, thin-bedded, white to gray quartzite of Blackstone Group standing above green schistose conglomerate containing many flattened white to gray quartzite pebbles and interbedded green calcareous quartz schist. Contact is probably a fault, but source of pebbles is quite obvious. In the same area, schist of Blackstone Group is difficult to distinguish from those of the Bellingham because of low-grade metamorphism of Blackstone rocks; it is probable that some of the low-grade Blackstone Rocks mapped northwest of Woonsocket in Blackstone River valley are part of Bellingham. The two rock units have been traditionally distinguished in the past by presence or absence of epidote (Warren and Powers, 1914), but this needs further study. Age is uncertain. Rocks have customarily been correlated with those of Pennsylvanian Narragansett basin; however, rocks in some exposures, such as the one at River St and Blackstone St in Woonsocket resemble Proterozoic Z Roxbury Conglomerate in Boston basin. Skehan and others (1979) suggest that Bellingham may have a similar age to that of Roxbury. This is supported by observation that Bellingham is a structural trough extending southwest from Boston basin and separating primarily Proterozoic Z granitoids from altered, but nongneissic, Proterozoic granitoids (Wones and Goldsmith, 1991). In deference to tradition, and because Proterozoic Z age has not been proven, age is shown on MA State bedrock map of Zen and others as Proterozoic Z to Pennsylvanian [map actually has age of Proterozoic Z, Cambrian, or Pennsylvanian, which differs from age stated in this report.] (Goldsmith, 1991).
Cambridge Argillite (Proterozoic Z to earliest Paleozoic)
Cambridge Argillite - Gray argillite and minor quartzite; rare sandstone and conglomerate. Contains acritarchs. Cambridge Argillite of Boston Bay Group contains sandy horizons which are in some places quartzite. Most prominent are Milton quartzite unit of Billings (1976), and Tufts Quartzite Member (described by Billings, 1929, and LaForge, 1932) in northern part of basin. Red sandstone and sandy argillite in Chelsea, Revere, and Milton-Quincy areas intertongue with green argillite (Kaye, 1980). Red beds lie above cleaner quartzites such as Tufts and Milton units. Core analysis by D.A. Ashenden (Metropolitan District Commission, 1980, written commun.) indicates that Cambridge and Braintree Argillites are identical. Age of Boston Bay rocks has been controversial and was once thought to be Cambrian to Pennsylvanian (the latter based on lithologic similarity to rocks of Narragansett basin and now discredited plant fossils). Age of Cambridge and of Boston Bay Group as a whole is Proterozoic Z and possibly Early Cambrian based on presence of acritarchs in Cambridge. Acritarchs are diagnostic species that ranges in age from Proterozoic Z to Early Cambrian, but is most abundant in Proterozoic Z time (Lenk and others, 1982; [also see Goldsmith and others, 1982]). Age is also supported by the following: 1) plant fossils so numerous in strata of Narragansett basin are absent in the Boston Bay Group strata, 2) Late Ordovician and Early Silurian Quincy Granite contains argillite inclusions that are on strike with Cambridge Argillite, and 3) Boston Bay Group stratigraphy is primarily marine, not similar to terrestrial stratigraphy of Narragansett basin (Goldsmith, 1991).
Dighton Conglomerate (Upper Pennsylvanian)
Dighton Conglomerate - Coarse conglomerate having sandy matrix; minor sandstone. Dighton Conglomerate occurs in Narragansett basin. Consists of gray conglomerate composed mainly of rounded quartzite cobbles to boulders containing subordinate rounded granite cobbles and slate pebbles; very little sand matrix; lenses of medium-grained sandstone form less than 20 percent of unit. Age is Pennsylvanian (Goldsmith, 1991).
East Berlin Formation (Lower Jurassic)
East Berlin Formation - Pale red conglomerate and arkosic sandstone. Assigned to Newark Supergroup (Robinson and Luttrell, 1985).
East Berlin Formation (Lower Jurassic)
East Berlin Formation - Reddish-brown to pale red arkosic sandstone and siltstone, and gray sandstone, gray mudstone, and black shale; interpreted as lake beds. Assigned to Newark Supergroup (Robinson and Luttrell, 1985). The East Berlin Formation of the Hartford basin contains eight facies: trough cross-bedded sandstones, horizontally stratified sandstones, interbedded sandstones and mudrocks, ripple cross-laminated siltstones, black shales, stratified mudrocks, disrupted shales, and disrupted mudstones. These facies are interpreted as a continental depositional system and are divided into two assemblages. Sandflat/alluvial plain facies assemblage (sandstones and siltstones) is composed of sheet-flood deposits. The lacustrine assemblage (shales and mudrocks) represents a saline lake-playa system (Gierlowski-Kordesch, and Rust, 1994).
Mount Toby Formation (Lower Jurassic)
Mount Toby Formation - Reddish-brown to pale red arkosic sandstone, and gray sandstone, gray siltstone, and black shale interpreted as lake beds.
Portland Formation (Lower Jurassic)
Portland Formation - Reddish-brown to pale red arkose and siltstone, and gray sandstone, gray siltstone, and black shale interpreted as lake beds.
Red arkosic conglomerate, sandstone, and siltstone (Upper Triassic)
Red arkosic conglomerate, sandstone, and siltstone - In Essex County.
Rhode Island Formation (Upper and Middle Pennsylvanian)
Rhode Island Formation - Conglomerate, sandstone, and graywacke. Rhode Island Formation is thickest and most extensive formation in Narragansett basin. Does not extend to Norfolk basin. Consists of gray sandstone and siltstone and lesser amounts of gray to black shale, gray conglomerate, and coal beds 10 m thick. Interfingers with Wamsutta Formation in Narragansett basin. In places overlies Dedham Granite. Age is Middle and Late Pennsylvanian (Goldsmith, 1991).
Rhode Island Formation (Upper and Middle Pennsylvanian)
Rhode Island Formation - Sandstone, graywacke, shale and conglomerate; minor beds of meta-anthracite. Fossil plants. Rhode Island Formation is thickest and most extensive formation in Narragansett basin. Does not extend to Norfolk basin. Consists of gray sandstone and siltstone and lesser amounts of gray to black shale, gray conglomerate, and coal beds 10 m thick. Interfingers with Wamsutta Formation in Narragansett basin. In places overlies Dedham Granite. Age is Middle and Late Pennsylvanian (Goldsmith, 1991).
Roxbury Conglomerate (Proterozoic Z to earliest Paleozoic)
Roxbury Conglomerate - Conglomerate, sandstone, siltstone, argillite, and melaphyre. Consists of Brookline, Dorchester, and Squantum Members. Roxbury Conglomerate forms base of Boston Bay Group. Divided into Brookline, Dorchester, and Squantum Members. Conglomerate in Brookline Member contains clasts of Dedham Granite, quartzite (possibly from Westboro Formation), and volcanic rock from underlying Mattapan Volcanic Complex. Dorchester Member consists of interbedded argillite and sandstone and forms an intermediate unit between Brookline Member and overlying Cambridge Argillite. Uppermost Squantum Member is a distinctive diamictite which appears to pinch out in northern part of basin. Brighton Melaphyre lies within Brookline Member and consists of mafic volcanic rocks (quartz keratophyre, keratophyre, and spilite). Roxbury clearly lies nonconformably on Dedham Granite near Hull, MA; can be traced continuously over Mattapan Volcanic Complex. Age is Proterozoic Z and possibly Early Cambrian (Goldsmith, 1991).
Shuttle Meadow Formation (Lower Jurassic)
Shuttle Meadow Formation - Pale red conglomerate and arkosic sandstone. The Shuttle Meadow Formation is assigned to Newark Supergroup and is extended into MA in the Hartford basin. It consists of sandstone strata containing one interval of gray mudstone beds. The unit grades eastward along strike into a conglomeratic facies. It overlies the New Haven Arkose or Hitchcock Volcanics and underlies the Holyoke Basalt (Robinson and Luttrell, 1985).
Shuttle Meadow Formation (Lower Jurassic)
Shuttle Meadow Formation - Reddish-brown to pale red arkosic sandstone and siltstone, and gray sandstone, gray mudstone, and black shale; interpreted as lake beds. The Shuttle Meadow Formation is assigned to Newark Supergroup and is extended into MA in the Hartford basin. It consists of sandstone strata containing one interval of gray mudstone beds. The unit grades eastward along strike into a conglomeratic facies. It overlies the New Haven Arkose or Hitchcock Volcanics and underlies the Holyoke Basalt (Robinson and Luttrell, 1985).
Sugarloaf Formation (Lower Jurassic)
Sugarloaf Formation - Reddish-brown to pale red arkose, and gray sandstone, gray siltstone, and black shale interpreted as lake beds.
Sugarloaf Formation (Lower Jurassic)
Sugarloaf Formation - Pale red conglomerate and arkosic sandstone, coarsens eastward.
Sugarloaf Formation (Upper Triassic)
Sugarloaf Formation - Red, pink, and gray coarse-grained, locally conglomeratic arkose, interbedded with brick-red shaley siltstone and fine-grained arkosic sandstone; boundary between Lower Jurassic (Js, Jsc) and Upper Triassic (TRs) parts are arbitrarily drawn through rocks of similar lithology on basis of Lower Jurassic palynofloral zone in gray mudstone immediately below Deerfield (Jdb); TRs is continuous with and lithically similar to TRn near Northampton. Assigned to Newark Supergroup and revised to include all sedimentary strata in the Deerfield basin below the Deerfield Basalt or its projected horizon. The Late Triassic-Early Jurassic boundary is arbitrarily drawn through clastic rocks consisting of coarse-grained, locally conglomeratic arkose interbedded with sandstone and siltstone below a Lower Jurassic palynofloral zone in gray mudstone just below the base of the Deerfield Basalt. The Sugarloaf is continuous with and lithologically similar to the New Haven Arkose in the Hartford basin (Robinson and Luttrell, 1985).
Turner Falls Sandstone (Lower Jurassic)
Turner Falls Sandstone - Pale red conglomerate and arkosic sandstone.
Turner Falls Sandstone (Lower Jurassic)
Turner Falls Sandstone - Reddish-brown to pale red arkosic sandstone, and gray sandstone, gray siltstone, and black shale interpreted as lake beds.
Wamsutta Formation (Middle and Lower Pennsylvanian)
Wamsutta Formation - Red to pink, well-sorted conglomerate, graywacke, sandstone, and shale; fossil plants. Wamsutta Formation occurs in Narragansett and Norfolk basins. Consists of conglomerate, lithic graywacke, sandstone, and shale. Also contains rhyolite and basalt horizons near Attleboro. Northwest of Attleboro, Wamsutta overlies Diamond Hill Felsite as used by Skehan and Murray (in Skehan and others, 1979). Volcanic rocks similar to Diamond Hill Felsite crop out west of Lake Pearl, between Franklin and Wrentham, on west flank of Norfolk basin. These are shown within Wamsutta Formation on MA State bedrock map of Zen and others (1983) because of their proximity to Diamond Hill. They also resemble Proterozoic Z Mattapan Volcanic Complex. Chute (1966) described lenses of carbonate rock in red and green shale in Wamsutta in Norwood quad. Limestone also observed in rocks mapped as Wamsutta adjacent to exposed Dedham Granite at Manchester Pond Reservoir (J.P. Schafer, 1982, oral commun.). Red and green shales may actually be Cambrian. Upper member of Pondville Conglomerate grades into and interfingers with Wamsutta; in turn, Wamsutta interfingers with Rhode Island Formation in northwest part of Narragansett basin. Nonconformably overlies Dedham Granite. Partly equivalent to Rhode Island Formation. Age is Early and Middle Pennsylvanian. Contains a few plant fossils (Goldsmith, 1991).
Maryland
Allegheny Formation and Pottsville Formation (Pennsylvanian)
Allegheny Formation - Interbedded sandstone, siltstone, claystone, shale, and coal beds; Upper Freeport coal at top; where present, Brookville coal defines base; thickness 275 feet in northeast, increases to 325 feet in south and west. And Pottsville Formation - Interbedded sandstone, siltstone, claystone, shale, and coal beds; conglomeratic orthoquartzite and protoquartzite at base; thickness 60 feet in northeast, increases to 440 feet in southwest
"Chemung" Formation, Parkhead Sandstone, Brallier Formation, and Harrell Shale (Devonian)
"Chemung" Formation - Predominantly marine beds characterized by gray to olive-green graywacke, siltstone, and shale; thickened ranges from 2,000 to 3,000 feet; Parkhead Sandstone - Gray to olive-green sandy shale, conglomeratic sandstone and graywacke; present in Washington County, identification uncertain in west; thickness averages 400 feet; Brallier Fomation - (Woodmont Shale of earlier reports). Medium to dark gray, laminated shale and siltstone; weathers to light olive-gray; grain size coarsens upward; thickness about 2,000 feet in west, about 1,7000 feet in east; and Harrell Shale - Dark gray laminated shale; absent in east where Brallier lies directly on Mahantango, Tully Limestone lies near base in west, in subsurface of Garrett County; total thickness in west 140 to 300 feet.
Chesapeake Group; Calvert Formation (Miocene)
Chesapeake Group; Calvert Formation - Plum Point Marls Member: Interbedded dark green to dark bluish-gray, fine-grained argillaceous sand and sandy clay; contains prominent shell beds and locally silica-cemented sandstones; and Fairhaven Member: Greenish-blue diatomaceous clay, weathers to pale gray; pale brown to white, fine-grained argillaceous sand; and greenish-blue sandy clay; total thickness 0 to 150 feet.
Chesapeake Group; Choptank Formation (Miocene)
Chesapeake Group; Choptank Formation - Interbedded brown to yellow very fine-grained to fine-grained sand and gray to dark bluish-green argillaceous silt; locally indurated to calcareous sandstone; prominent shell beds; thickness 0 to 50 feet.
Clinton Group, including Rochester Shale (Silurian)
Clinton Group, including Rochester Shale - Gray, thin-bedded calcareous shale and dark gray, thin- to medium-bed7 ded lenticular limestone; thickness 25 to 40 feet; Keefer Sandstone - White to yellowish-gray, thick-bedded protoquartzite and orthoquartzite; calcareous to west; thickness 10 feet in west, increases to 35 feet in east; and Rose Hill Formation - Olive-gray to drab, thin-bedded shale; some purple shale and gray, thin-bedded sandstone; including Cresaptown Iron Sandstone Member - Purple, hematite-cemented, quartzose sandstone; thickness 5 to 30 feet; occurs in lower half of formation; total thickness 300 feet in east, increases to 570 feet in west.
Conemaugh Formation (Pennsylvanian)
Conemaugh Formation - Includes the rocks between the base of the Pittsburgh coal and the top of the Upper Freeport coal; consists of two unnamed members which are separated by the Barton coal; both members are gray and brown claystone, shale, siltstone and sandstone, with several coal beds; lower member also contains redbeds and fossiliferous marine shales; thickness 825 to 925 feet.
Conococheague Limestone (Upper Cambrian to Lower Ordovician )
Conococheague Limestone - Dark blue, laminated, oolitic, argillaceaous, and siliceous limestone, algal limestone, and flat-pebble conglomerate; siliceous shale partings; some sandstone and dolomite; thickness 1,600 to 1,900 feet.
Dunkard Group (Permian)
Dunkard Group - Red and green shale, siltstone, and sandstone, with thin lenticular beds of argillaceous limestone and thin beds of impure coal; thick-bedded, white conglomeratic sandstone at base; thickness greater than 200 feet; occurs only on hilltop
Gettysburg Shale (Triassic)
Gettysburg Shale - Red shale and soft red sandstone and siltstone; estimated thickness less than 5,000 feet.
Greenbrier Formation (Mississippian)
Greenbrier Formation - Upper part red calcareous shale and sandstone interbedded with greenish-gray and reddish-gray argillaceous limestone; Loyalhanna Limestone Member: Gray to red, cross-bedded, arenaceous calcarenite; total thickness 200 to 300 feet.
Hamilton Group (including Mahantango Formation and Marcellus Shale), and including Tioga Metabentontite Bed, and Needmore Shale (Devonian)
Hamilton Group including Mahantango Formation - Dark gray, laminated shale, siltstone, and very fine-grained sandstone; thickness 600 feet in west, increases to 1,200 feet in east, and Marcellus Shale - Gray-black, thinly laminated, pyritic, carbonaceous shale; thickness 250 feet in east, increases to 500 feet in west. Also includes Tioga Metabentonite Bed - Brownish-gray, thinly laminated shale containing sand-size mica flakes; thickness less than one foot; and Needmore Shale - Olive-gray to black shale and dark, thin-bedded, fossiliferous, argillaceous limestone; thickness ranges from 70 to 145 feet.
Hampshire Formation (Devonian)
Hampshire Formation - Interbedded red shale, red mudstone, and red to brown cross-bedded siltstone and sandstone; some thin green shale; greenish-gray sandstone and shale toward top; fragmentary plant fossils; thickness 1,400 to 2,000 feet in west, increases to 3,800 feet in east.
Helderberg Formation and Keyser Limestone (Devonian)
Helderberg Formation, including Licking Creek Limestone Member - (Becraft Limestone of earlier reports.) Present only in east. Medium gray, medium-grained limestone near top; bedded black chert and thin-bedded limestone in middle; silty argillaceous limestone and shale near base; contains tongues of Shriver and Mandata; thickness 110 feet; Mandata Shale Member - Dark brown to black, thin-bedded shale; fossiliferous; thickness 20 to 30 feet in west, intertongues with Licking Creek Limestone Member in east; Corriganville Limestone Member (Head) - (New Scotland Limestone of earlier reports.) Medium gray, medium-grained, medium-bedded limestone, interbedded with chert; fossiliferous; thickness 15 to 30 feet; New Creek Limestone Member - (Coeymans Limestone of earlier reports.) Medium gray, thick-bedded, coarse-grained limestone; fossiliferous; thickness 9 to 10 feet. Limestone changes facies eastward into sandstone, the Elbow Ridge Sandstone Member - Medium-bedded, medium- to coarse-grained, calcarous sandstone; thickness 10 to 18 feet.; and the Keyser Limestone - Dark gray, thin- to thick-bedded, fine- to coarse-grained calcarenite; contains nodular limestone, dolomitic limestone, and calcarous shale; cherty near top; fossiliferous; thickness 200 to 300 feet.
Juniata Formation (Ordovician)
Juniata Formation - Red to greenish-gray, thin- to thick-bedded siltstone, shale, subgraywacke, and protoquartzite; interbedded conglomerate; thickness 180 feet in east, increases to 500 feet in west.
Mauch Chunk Formation (Mississippian)
Mauch Chunk Formation - Red and green shale, reddish-purple mudstone, and red, green, brown, and gray thin-bedded and cross-bedded sandstones; thickness 500 feet in west, increases to about 800 feet in east.
McKenzie Formation (Silurian)
McKenzie Formation - Gray, thin-bedded shale and argillaceous limestone; interbedded red sandstone and shale in east; thickness 160 feet in western Washington County, increases to 300 feet in east and 380 feet in west.
Monongahela Formation (Pennsylvanian)
Monongahela Formation - Interbedded claystone, argillaceous limestone, shale, sandstone, and coal beds; Waynesburg coal at top; Pittsburg coal at base; thickness 240 feet in west, increases to 375 feet in east.
New Oxford Formation (Triassic)
New Oxford Formation - Red, maroon, and gray sandstone, siltstone, and shale; basal conglomerate member: From vicinity of Maryland Rte. 73 and southward, limestone conglomerate with red and gray calcareous matrix; northward, quartz conglomerate with red sandy matrix; estimated total thickness 4,500 feet.
Pocono Group, including the Purslane Sandstone and Rockwell Formation (Mississippian)
Pocono Group - Gray, white, tan, and brown, thin- to thick-bedded, cross-bedded sandstone, locally conglomeratic; interbedded gray and reddish-brown shale, mudstone, and siltstone; fragmentary plant fossils. Undifferentiated in Garrett and western Allegeny Counties. Includes Purslane Sandstone - White, thick-bedded, coarse-grained sandstone and conglomerate with thin coal beds and red shales. Eastern Allegany and Washington Counties. And also inlcudes Rockwell Formation - Coarse-grained arkosic sandstone, fine-grained conglomerate, and buff shale; dark shale with thin coal beds near base. Eastern Allegany and Washington Counties.
Tonoloway Limestone (Silurian)
Tonoloway Limestone - Gray, thin-bedded limestone, dolomitic limestone, and calcareous shale; thin sandstone member in east 20 feet above base; fossiliferous; thickness 400 feet in east, increases to 600 feet in west.
Waynesboro Formation (Cambrian)
Waynesboro Formation - Upper part red, gray, and yellowish-brown, thin-bedded siltstone, shale, and ripple-marked, cross-bedded sandstone; lower part interbedded dark gray to red shale and thin-bedded dolomite; thickness approximately 600 feet.
Wills Creek Shale and Bloomsburg Formation (Silurian)
Wills Creek Shale - Olive to yellowish-gray, thin-bedded mudstone, calcareous shale, argillaceous limestone, and sandstone; thickness 450 feet in west, increases to 600 feet in east; and Bloomsburg Formation - Bright red, hematitic, thin- to thick-bedded sandstone and shale; some dark sandstone and green shale; Cedar Creek Limestone Member - Dark gray, fine- to medium-grained argillaceous limestone, occurs in middle part of formation; total thickness 20 feet in west, increases to 200 feet in east.
Maine
Cambrian Caucomgomoc Lake Formation, quartzwacke and pelite member (Cambrian)
Cambrian Caucomgomoc Lake Formation quartzwacke and pelite member
Cambrian Grand Pitch Formation (Cambrian)
Cambrian Grand Pitch Formation
Cambrian Hurricane Mountain Formation, metaquartzwacke (Cambrian)
Cambrian Hurricane Mountain Formation, metaquartzwacke
Cambrian Jim Pond Formation, quartzwacke and pelite (Cambrian)
Cambrian Jim Pond Formation, quartzwacke and pelite
Cambrian Loon Stream Formation (Cambrian)
Cambrian Loon Stream Formation
Carboniferous - Devonian unnamed conglomerate and sandstone (Carboniferous and/or Devonian)
Carboniferous - Devonian unnamed conglomerate and sandstone
Devonian Beck Pond Limestone (Devonian)
Devonian Beck Pond Limestone
Devonian - Cambrian unnamed sedimentary rocks (Devonian-Cambrian)
Devonian - Cambrian unnamed sedimentary rocks
Devonian Carrabassett Formation thinly layered member (Devonian)
Devonian Carrabassett Formation thinly layered member
Devonian Chapman Sandstone (Devonian)
Devonian Chapman Sandstone
Devonian Hartin Formation (Devonian)
Devonian Hartin Formation
Devonian Mapleton Formation (Devonian)
Devonian Mapleton Formation
Devonian Matagamon Sandstone (Devonian)
Devonian Matagamon Sandstone
Devonian - Ordovician Bucksport Formation (Devonian - Ordovician)
Devonian - Ordovician Bucksport Formation
Devonian - Ordovician Dideguash Formation (Devonian - Ordovician)
Devonian - Ordovician Dideguash Formation
Devonian Perry Formation sandstone member (Devonian)
Devonian Perry Formation sandstone member
Devonian Seboomook Formation (Devonian)
Devonian Seboomook Formation
Devonian - Silurian Allagash Lake Formation mixed sedimentary rocks (Devonian - Silurian)
Devonian - Silurian Allagash Lake Formation mixed sedimentary rocks
Devonian - Silurian Bar Harbor Formation (Devonian - Silurian)
Devonian - Silurian Bar Harbor Formation
Devonian - Silurian Calderwood Formation (Devonian - Silurian)
Devonian - Silurian Calderwood Formation
Devonian - Silurian Daggett Ridge Formation (Devonian - Silurian)
Devonian - Silurian Daggett Ridge Formation
Devonian - Silurian Fish River Lake Formation (Devonian - Silurian)
Devonian - Silurian Fish River Lake Formation
Devonian - Silurian Fogelin Hill Formation (Devonian - Silurian)
Devonian - Silurian Fogelin Hill Formation
Devonian - Silurian Rindgemere Formation upper member (Devonian - Silurian)
Devonian - Silurian Rindgemere Formation upper member
Devonian - Silurian undifferentiated sedimentary rocks of the Spider Lake, Chandler Pond and Third Lake Formations (Devonian - Silurian)
Devonian - Silurian undifferentiated sedimentary rocks of the Spider Lake, Chandler Pond and Third Lake Formations
Devonian - Silurian unnamed conglomeratic sandstone (Devonian - Silurian)
Devonian - Silurian unnamed conglomeratic sandstone
Devonian - Silurian unnamed sedimentary rocks (Devonian - Silurian)
Devonian - Silurian unnamed sedimentary rocks
Devonian Tarratine Formation (Devonian)
Devonian Tarratine Formation
Devonian Tarratine Formation McKenny Pond Limestone (Devonian)
Devonian Tarratine Formation McKenny Pond Limestone
Devonian Tomhegan Formation (Devonian)
Devonian Tomhegan Formation
Devonian Trout Valley Formation (Devonian)
Devonian Trout Valley Formation
Devonian unnamed sedimentary rocks (Devonian)
Devonian unnamed sedimentary rocks
Ordovician Benner Hill formation (Ordovician)
Ordovician Benner Hill formation
Ordovician - Cambrian Cookson Formation lithic sandstone and pelite (Ordovician - Cambrian)
Ordovician - Cambrian Cookson Formation lithic sandstone and pelite
Ordovician - Cambrian Cookson Formation sulfidic quartzose sandstone (Ordovician - Cambrian)
Ordovician - Cambrian Cookson Formation sulfidic quartzose sandstone
Ordovician - Cambrian Saint Daniel formation quartzite and red and green shale (Ordovician - Cambrian)
Ordovician - Cambrian Saint Daniel formation quartzite and red and green shale
Ordovician - Cambrian Sawmill Formation (Ordovician - Cambrian)
Ordovician - Cambrian Sawmill Formation
Ordovician - Cambrian Southeast Cove Formation (Ordovician - Cambrian)
Ordovician - Cambrian Southeast Cove Formation
Ordovician - Cambrian unnamed sedimentary rocks (Ordovician - Cambrian)
Ordovician - Cambrian unnamed sedimentary rocks
Ordovician Madawaska Lake Formation (Ordovician)
Ordovician Madawaska Lake Formation
Ordovician Munsungun Lake Formation (Ordovician)
Ordovician Munsungun Lake Formation
Ordovician - Precambrian Z Cushing Formation sulfidic pelite (Ordovician - Precambrian Z)
Ordovician - Precambrian Z Cushing Formation sulfidic pelite
Ordovician - Precambrian Z interbedded pelite and quartz sandstone of the Passagassawakeag block (Ordovician - Precambrian Z)
Ordovician - Precambrian Z interbedded pelite and quartz sandstone of the Passagassawakeag block
Ordovician - Precambrian Z unnamed sedimentary rocks (Ordovician - Precambrian Z)
Ordovician - Precambrian Z unnamed sedimentary rocks
Ordovician unnamed quartz sandstone and pelite (Ordovician)
Ordovician unnamed quartz sandstone and pelite
Ordovician unnamed sandstone (Ordovician)
Ordovician unnamed sandstone
Ordovician unnamed sandstone and pelite (Ordovician)
Ordovician unnamed sandstone and pelite
Precambrian Z Ogier Point Formation (Precambrian)
Precambrian Z Ogier Point Formation
Precambrian Z rocks of Islesboro (Precambrian Z)
Precambrian Z rocks of Islesboro
Silurian Frenchville Formation (Silurian)
Silurian Frenchville Formation
Silurian Hardwood Mountain Formation (Silurian)
Silurian Hardwood Mountain Formation
Silurian Jemtland Formation (Silurian)
Silurian Jemtland Formation
Silurian Maple Mountain Formation (Silurian)
Silurian Maple Mountain Formation
Silurian - Ordovician Lobster Lake Formation (Silurian - Ordovician)
Silurian - Ordovician Lobster Lake Formation
Silurian - Ordovician Mattawamkeag Formation (Silurian - Ordovician)
Silurian - Ordovician Mattawamkeag Formation
Silurian - Ordovician Nine Lake formation (Silurian - Ordovician)
Silurian - Ordovician Nine Lake formation
Silurian - Ordovician unnamed sedimentary rocks (Silurian - Ordovician)
Silurian - Ordovician unnamed sedimentary rocks
Silurian - Ordovician Vassalboro formation (Silurian - Ordovician)
Silurian - Ordovician Vassalboro formation
Silurian Perry Mountain formation (Silurian)
Silurian Perry Mountain formation
Silurian Rangeley formation (Silurian)
Silurian Rangeley formation
Silurian Rangeley Formation "A""member (Silurian)
Silurian Rangeley Formation "A" member
Silurian Rangeley Formation "A" member lithic sandstone" (Silurian)
Silurian Rangeley Formation "A" member lithic sandstone
Silurian Rangeley Formation "B" member (Silurian)
Silurian Rangeley Formation "B" member"
Silurian Rangeley Formation "C" member (Silurian)
Silurian Rangeley Formation "C" member
Silurian Ripogenus Formation (Silurian)
Silurian Ripogenus Formation
Silurian Sangerville Formation (Silurian)
Silurian Sangerville Formation
Silurian Smalls Falls Formation (Silurian)
Silurian Smalls Falls Formation
Silurian Smalls Falls Formation? (Silurian)
Silurian Smalls Falls Formation?
Silurian undifferentiated conglomerates and coarse-grained sandstones (Silurian)
Silurian undifferentiated conglomerates and coarse-grained sandstones, in part of the Allsbury Formation and in part unnamed
Silurian undifferentiated pelites and sandstones (Silurian)
Silurian undifferentiated pelites and sandstones, in part of the Allsbury Formation and in part unnamed
Silurian undifferentiated sandstones (Silurian)
Silurian undifferentiated sandstones, in part of the Allsbury Formation and in part unnamed
Silurian unnamed conglomerate and sandstone (Silurian)
Silurian unnamed conglomerate and sandstone
Silurian unnamed sandstone (Silurian)
Silurian unnamed sandstone
Silurian unnamed sedimentary rocks (Silurian)
Silurian unnamed sedimentary rocks
Michigan
Baraga Group; Tyler Formation (Early Proterozoic)
Baraga Group; Tyler Formation - Light- to dark-gray, feldspathic, fine-grained sandstone, argillaceous siltstone, and argillite. Near base, ferruginous argillite contains beds of cherty sideritic and pyritic iron-formation
Bass Island Dolomite (Late Silurian)
Bass Island Dolomite
Bayport Limestone (Mississippian)
Bayport Limestone
Bedford Shale (Late Devonian)
Bedford Shale
Berea Sandstone (Late Devonian)
Berea Sandstone
Cataract Formation (Early Silurian)
Cataract Formation
Coldwater Shale (Mississippian)
Coldwater Shale
Copper Harbor Conglomerate (Middle Proterozoic)
Copper Harbor Conglomerate - Red lithic conglomerate and sandstone; mafic to felsic volcanic flows similar to those of the unnamed formation (unit Yu) are interlayered with the sedimentary rocks.
Detroit River Group (Middle Devonian)
Detroit River Group
Ellsworth Shale (Late Devonian)
Ellsworth Shale
Grand River Formation (Pennsylvanian)
Grand River Formation
Jacobsville Sandstone (Middle Proterozoic)
Jacobsville Sandstone - Red, brown, and white quartzose sandstone, and minor siltstone, shale and conglomerate
Marshall Sandstone (Mississippian)
Marshall Sandstone
Michigan Formation (Mississippian)
Michigan Formation
Munising Formation (Late Cambrian)
Munising Formation
Oronto Group; Nonesuch Shale (Middle Proterozoic)
Oronto Group; Nonesuch Shale - Gray, green, and brown lithic siltstone, shale, and sandstone. Copper sulfides and native copper occur locally near base
Paleozoic undivided (Paleozoic)
Paleozoic undivided
Prairie du Chien Group (Early Ordovician)
Prairie du Chien Group
Saginaw Formation (Pennsylvanian)
Saginaw Formation
Sylvania Sandstone (Early Devonian)
Sylvania Sandstone
Trempealeau Formation (Late Cambrian)
Trempealeau Formation
Minnesota
Coleraine Formation (Cretaceous)
Coleraine Formation - Jasper-pebble conglomerate, sandstone, and shale of diverse origin on the Mesabi range of northern Minnesota, and unnamed sandstone and shale of nonmarine to marine origin in east-central Minnesota
Cretaceous rocks, undivided (Cretaceous)
Cretaceous rocks, undivided - Dakota, Graneros, Greenhorn, Carlie, Niobara, and Pierre formations and their nonmarine equivalents in northwestern, southwestern, and southeastern Minnesota
Denham Formation (Early Proterozoic)
Denham Formation - Quartz arenite and siltstone, oxide iron-formation, marble, mafic hypabyssal intrusions and fragmental volcanic rocks metamorphosed to the staurolite grade of the amphibolite facies
Fond du Lac Formation (Middle Proterozoic)
Fond du Lac Formation - Red to dark-brown shale, feldspathic sandstone, and arkose of fluvial origin. Includes the Oldenberg Point Member, a pronounced basal unit of quartz-pebble conglomerate in the Duluth area.
Jurassic rocks, undivided (Jurassic)
Jurassic rocks, undivided - Unnamed units of green, gray, brown, and red shale, white to tan micritic limestone and dolostone, and white, fine- to coarse-grained sandstone and siltstone; unit contains nodules of chert and gypsum
Lower Ordovician rocks, undivided (Lower Ordovician)
Lower Ordovician rocks, undivided - Shakopee and Oneota Formations of the Prairie du Chien Group in the Hollandale embayment of southeastern Minnesota. Unit consists dominantly of dolostone and dolomitic limestone. The Shakopee also contains intervals of quartz arenite, including a pronounced basal unit named the New Richmond Member
Middle and Upper Ordovician rocks, undivided (Middle and Late Ordovician)
Middle and Upper Ordovician rocks, undivided - Sandstone and shaly sandstone of the Winnipeg Formation and limestone and dolomitic limestone of the Red River Formation along the east edge of the Williston Basin in northwestern Minnesota
Middle Ordovician rocks, undivided (Middle Ordovician)
Middle Ordovician rocks, undivided - Decorah Shale; limestone of the Platteville Formation; shaly rocks of the Glenwood Formation; and St. Peter Sandstone in the Hollandale embayment of southeastern Minnesota
North Shore Volcanic Group; Reversely polarized volcanic rocks, undivided (Middle Proterozoic)
North Shore Volcanic Group; Reversely polarized volcanic rocks, undivided - Mixed tholeiitic diabasic and porphyritic basalt, trachybasalt, and rhyolite in far northeastern Minnesota and porphyritic and diabasic basalt near Duluth. Includes units of a basal quartz arenite, Puckwunge Sandstone and Nopeming Formation, in northeastern Minnesota and near Duluth, respectively.
Solor Church Formation (Middle Proterozoic)
Solor Church Formation - Dark-red to dark-brown shale, siltstone, and lithic sandstone of fluvial origin in Scott and Carver Counties; metamorphosed to zeolite facies
Upper Cambrian, undivided (Late Cambrian)
Upper Cambrian, undivided - Jordan Sandstone; dolomite, glauconite, and silty glauconite rocks of the St. Lawerence and Franconia Formation; Ironton and Galesville Sandstones; sandy and shaly rocks of the Eau Claire Formation; and the Mt. Simon Sandstone.
Missouri
CHANNEL SANDSTONES (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian)
CHANNEL SANDSTONES
CHEROKEE GROUP- Cabaniss Subgroup, Krebs Subgroup (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Middle Desmonian])
CHEROKEE GROUP - Cabaniss Subgroup - cyclic deposits, shale, sandstone, clay and several workable coal beds. Krebs Subgroup - cyclic deposits, sandstone, siltstone, shale, clay and some workable coal beds
CHESTERIAN SERIES (Phanerozoic | Paleozoic | Carboniferous Mississippian-Late [Chesterian])
CHESTERIAN SERIES - FAYETTEVILLE FORMATION, BATESVILLE FORMATION, HINDVILLE LIMESTONE, VIENNA LIMESTONE, TAR SPRINGS SANDSTONE, GLEN DEAN FORMATION, HARDINSBURG FORMATION, GOLCONDA FORMATION, CYPRESS FORMATION, PAINT CREEK FORMATION, YANKEETOWN SANDSTONE, RENAULT FORMATION, AUX VASES SANDSTONE, STE. GENEVIEVE LIMESTONE
DEVONIAN SYSTEM (Phanerozoic | Paleozoic | Devonian-Early Devonian-Middle(?) Devonian-Late)
DEVONIAN SYSTEM - CHATTANOOGA SHALE, SYLAMORE SANDSTONE, FORTUNE FORMATION, HOLTS SUMMIT SANDSTONE, SNYDER CREEK SHALE, CEDAR VALLEY LIMESTONE, LOUISIANA LIMESTONE, SAVERTON SHALE, GRASSY CREEK SHALE, TURPIN SANDSTONE, BUSHBERG SANDSTONE, GLEN PARK LIMESTONE, St. LARENT LIMESTONE, BEAUVAIS SANDSTONE, GRAND TOWER LIMESTONE, CLEAR CREEK CHERT, LITTLE SALINE LIMESTONE, GRASSY KNOB CHERT, BAILEY FORMATION
DOUGLAS GROUP (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Upper Virgilian])
DOUGLAS GROUP - cyclic deposits, dominantly shale with sandstone, and limestone.
ELVINS GROUP- (INCLUDING DERBY-DOERUN DOLOMITE, DAVIS FORMATION), BONNETERRE DOLOMITE (Phanerozoic | Paleozoic | Cambrian-Furongian [Croixian])
ELVINS GROUP - (INCLUDING DERBY - DOERUN DOLOMITE - alternating thin dolomite, siltstone, and shale; DAVIS FORMATION - glauconitic shale with fine - grained sandstone, limestone, and dolomite); BONNETERRE DOLOMITE - dolomite, dolomitic limestone, and limestone; glauconitic in lower part
GASCONADE DOLOMITE (Phanerozoic | Paleozoic | Ordovician-Early [Ibexian])
GASCONADE DOLOMITE - coarse - crystalline cherty dolomite with a basal Gunter Sandstone Member.
GULFIAN SERIES (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian])
GULFIAN SERIES - Owl Creek Formation - massive, sandy, micaceous, fossilliferous, glauconitic marine clay, max 100 ft. McNairy Formation - unconsolidated sandstone with clay and gravel lenses, max of 250 ft.
HALE SANDSTONE (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early [Lower Morrowian])
HALE SANDSTONE, restricted to an isolated exposure in McDonald County, southwest Missouri
JOACHIM DOLOMITE, DUTCHTOWN FORMATION (Phanerozoic | Paleozoic | Ordovician-Middle [Mohawkian])
JOACHIM DOLOMITE, DUTCHTOWN FORMATION
KANSAS CITY GROUP (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Upper Missourian])
KANSAS CITY GROUP - cyclic deposits, limestone and shale with minor sandstone and coal.
KINDERHOOKIAN SERIES (Phanerozoic | Paleozoic | Carboniferous Mississippian-Early [Kinderhookian])
KINDERHOOKIAN SERIES - NORTHVIEW SHALE, SEDALIA FORMATION, COMPTON LIMESTONE, BACHELOR FORMATION CHOUTEAU GROUP, HANNIBAL SHALE, HORTON CREEK LIMESTONE
LAMOTTE SANDSTONE (Phanerozoic | Paleozoic | Cambrian-Furongian [Croixian])
LAMOTTE SANDSTONE - sandstone with some dolomitic and shaly lenses; coarse - graines to conglomeratic and arkosic at base
LANSING GROUP (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Upper Missourian])
LANSING GROUP - cyclic deposits of limestone and shale
LEEMON FORMATION, MAQUOKETA GROUP, CAPE LIMESTONE, KIMMSWICK LIMESTONE, NOIX-CYRENE LIMESTONE, MAQUOKETA SHALE (Phanerozoic | Paleozoic | Ordovician-Middle Ordovician-Late)
LEEMON FORMATION, MAQUOKETA GROUP INCLUDING: (GIRARDEAU LIMESTONE, ORCHARD CREEK SHALE, THEBES SANDSTONE, CAPE La CROIX SHALE), CAPE LIMESTONE, KIMMSWICK LIMESTONE, NOIX - CYRENE LIMESTONE, MAQUOKETA SHALE
MARMATON GROUP (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Middle Desmonian])
MARMATON GROUP - cyclic deposits, shale and limestone with sandstone, clay and several coal beds, some workable
PENNSYLVANIAN UNDIFFERENTIATED (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian)
PENNSYLVANIAN UNDIFFERENTIATED
PLEASANTON GROUP (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Upper Missourian])
PLEASANTON GROUP - dominantly shale and sandstone with minor coal.
ROUBIDOUX FORMATION (Phanerozoic | Paleozoic | Ordovician-Early [Ibexian])
ROUBIDOUX FORMATION - sandstone, chert and interbedded dolomite
SHAWNEE GROUP (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Upper Virgilian])
SHAWNEE GROUP - cyclic deposits, limestone and shale with sandstone and siltstone.
SMITHVILLE DOLOMITE, POWELL DOLOMITE, COTTER DOLOMITE, JEFFERSON CITY DOLOMITE (Phanerozoic | Paleozoic | Ordovician-Early [Ibexian])
SMITHVILLE DOLOMITE, POWELL DOLOMITE, COTTER DOLOMITE, JEFFERSON CITY DOLOMITE - fine crystalline, silty, cherty dolomite, and oolitic chert with local sandstone beds
ST. PETER SANDSTONE, EVERTON FORMATION (Phanerozoic | Paleozoic | Ordovician-Early Ordovician-Middle)
ST. PETER SANDSTONE, EVERTON FORMATION
TERTIARY SYSTEM (Phanerozoic | Cenozoic | Tertiary | Paleocene Eocene(?) Oligocene(?) Miocene(?) Pliocene-Early(?) Pliocene-Middle(?) Pliocene-Late)
TERTIARY SYSTEM - PLIOCENE SERIES - Mounds Gravel (Lafayette Formation) - ferruginous, chert gravel, max of 60 ft. EOCENE SERIES - Wilcox Group - includes Holly Springs Formation - x - bedded sandstone, clay and gravel, max of 1200 ft.; Ackerman Formation - clay with lens of sand and gravel, max of 100ft. PALEOCENE SERIES - Midway Group - includes Porters Creek Clay - bentonitic clay, max of 200 ft.; Clayton Formation - marl, fossiliferous, calcareous, limonitic, glauconitic sand and clay, max of 20 ft.,
UNDIFFERENTIATED (Phanerozoic | Paleozoic | Ordovician)
UNDIFFERENTIATED (ORDOVICIAN ROCKS)
WABAUNSEE GROUP (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Upper Virgilian])
WABAUNSEE GROUP - cyclic deposits, principally shale, sitlstone, sandstone with thin limestone beds and minor coal
WELDON RIVER-WARRENSBURG-MOBERLY CHANNEL SANDSTONE (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Upper Missourian])
WELDON RIVER - WARRENSBURG - MOBERLY CHANNEL SANDSTONE
Mississippi
Catahoula formation (Miocene)
Catahoula formation - Irregularly bedded gray sand and sandstone; mottled red and gray, green, and chocolate-colored clay; some quartzite, and some gravel; the Paynes Hammock sand, sandy limestone cross-bedded fine green sand, and thin-bedded sand and clay, is mapped with the underlying Chickasawhay limestone in eastern MS.
Chester group (Mississippian)
Chester group - Sandstone, shale, and limestone.
Tallahatta formation and Neshoba sand (Eocene)
Tallahatta formation and Neshoba sand - (Claiborne group), Southeast of Pearl River predominantly more or less glauconitic claystone and clay with lenses of sand and some sandstone; highly cross-bedded sand at base; northwest of Pearl river predominantly sand, locally glauconitic, containing claystone and clay lenses and abundant clay stringers; Neshoba sand, sparingly glauconitic fairly coarse sand not recognized southeast of Newton County or north of Yalobusha River.
Montana
Arikaree formation (Phanerozoic | Cenozoic | Tertiary)
Arikaree formation: gray sandstone with layers of concretions; contains volcanic ash and, locally, channels filled with conglomerate; known only in southeastern Montana.
Basal part of Cody shale (Phanerozoic | Mesozoic | Cretaceous-Late)
Basal part of Cody shale: gray and dark-gray shale with some sandstone beds; in north end of Big Horn Basin includes the Telegraph Creek formation.
Bearpaw shale (Phanerozoic | Mesozoic | Cretaceous-Late)
Bearpaw shale: Dark-gray and brownish clay shale; thick units of nonfissile bentonitic shale; calcareous and ferruginous concretions throughout; contains some thick bentonite beds.
Belle Fourche shale (Phanerozoic | Mesozoic | Cretaceous-Late)
Belle Fourche shale: dark blue-gray siliceous shale with many calcareous and ferruginous concretions and intercalated thin layers of bentonite.
Cambrian, undifferentiated (Phanerozoic | Paleozoic | Cambrian)
Cambrian, undifferentiated: comprises Deadwood formation, in south-central Montana, and Red Lion formation, Dry Creek shale, Hasmark formation, Pilgrim limestone, Silver Hill formation, Park shale, Meagher limestone, Wolsey shale, Flathead quartzite, and other units. In a few places quartzite of Cambrian age may be mapped with the Belt series or quartzite of Belt age with the Cambrian rocks.
Claggett formation (Phanerozoic | Mesozoic | Cretaceous-Late)
Claggett formation: chiefly dark-gray shale with iron-stained concretions; locally sandstone present; numerous bentonite beds near base.
Cretaceous, undifferentiated (Phanerozoic | Mesozoic | Cretaceous)
Cretaceous, undifferentiated: used in only a few areas, such as the Disturbed Belt east of Glacier National Park, where subdivision in difficult.
Eagle sandstone (Phanerozoic | Mesozoic | Cretaceous-Late)
Eagle sandstone: sandstone and shaly sandstone with lignite beds in basal part of upper unit (Keu). The Virgelle sandstone member (Kvi) at base is distinguished where possible. Near Yellowstone National Park rocks incorrectly called Laramide in early reports and now regarded as roughly equivalent to the Eagle sandstone are tentatively mapped as Eagle sandstone. Gray to buff massive cliff-forming sandstone with iron stained concretions in the upper part. In western Montana the Virgelle is a formation and in central Montana it is the basal member of the Eagle sandstone.
Eagle sandstone (Phanerozoic | Mesozoic | Cretaceous-Late)
Eagle sandstone: sandstone and shaly sandstone with lignite beds in basal part of upper unit (Keu). The Virgelle sandstone member (Kvi) at base is distinguished where possible. Near Yellowstone National Park rocks incorrectly called Laramide in early reports and now regarded as roughly equivalent to the Eagle sandstone are tentatively mapped as Eagle sandstone.
Fort Union formation (Phanerozoic | Cenozoic | Tertiary Cretaceous-Late | Paleocene)
Fort Union formation: Clay shale, siltstone, and sandstone; local lenses of impure limestone, and numerous lignitic beds; contains Tertiary plant and animal fossils but no dinosaurs; base generally placed at the lowest of the succession of lignite beds within it; includes the Tongue River member, Lebo shale member, and Tullock member.
Fox Hill sandstone (Phanerozoic | Mesozoic | Cretaceous-Late)
Fox Hills sandstone: Typically shaly sandstone grading upward into massive brownish sandstone with white sandstone of the Colgate member locally at top.
Hell Creek formation (Phanerozoic | Mesozoic Cenozoic | Cretaceous-Late Tertiary | Paleocene)
Hell Creek formation: somber-gray sandstone and greenish shaly clay and mudstone containing dinosaur bones; a few thin lignite and subbituminous coal beds.
Horsethief sandstone (Phanerozoic | Mesozoic | Cretaceous-Late)
Horsethief sandstone: shaly sandstone grading upward into massive brownish cliff-forming sandstone with local concentrations of magnetite in beds near top.
Judith River formation (Phanerozoic | Mesozoic | Cretaceous-Late)
Judith River formation: light-colored sandstone at top; lower third somber-gray siltstone and sandy shale; greenish-gray clay and some lignite beds; includes the Parkman sandstone member of south-central Montana.
Lennep sandstone (Phanerozoic | Mesozoic | Cretaceous-Late)
Lennep sandstone: mainly dark-brown andesitic sandstone with intercalated shale; locally contains thin coal beds.
Paleozoic rocks, undifferentiated (Phanerozoic | Paleozoic)
Paleozoic rocks, undifferentiated: in east-central Madison County where scale did not permit differentiation on map.
Pennsylvanian, undifferentiated (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian)
Pennsylvanian, undifferentiated: in western Montana is mainly the Quadrant quartzite but includes limestone and other rocks of Pennsylvanian age so far as present data permit. Farther east other formations of Pennsylvanian or possible Pennsylvanian age are included.
Pierre shale (Phanerozoic | Mesozoic | Cretaceous-Late)
Pierre shale: dark-gray clay shale with calcareous and ferruginous concretions and sandy members.
St. Mary River formation (Phanerozoic | Mesozoic | Cretaceous-Late)
St. Mary River formation: Greenish-gray clay with local nodular limestone and crossbedded sandstone.
Telegraph Creek formation (Phanerozoic | Mesozoic | Cretaceous-Late)
Telegraph Creek formation: buff mainly soft, fissile sandy shale with subordinate amounts of concretionary sandstone.
Thermopolis shale (Phanerozoic | Mesozoic | Cretaceous-Early)
Thermopolis shale: dark-gray shale with some sandstone. The subsurface consists of Muddy sandstone member or Newcastle sandstone member at top, Skull Creek shale member in middle, and Fall River sandstone or First Cat Creek sand of drillers at base.
Wasatch formation (Phanerozoic | Cenozoic | Tertiary)
Wasatch formation: Light-colored massive sandstone; drab-colored shale and coal in southeastern Montana; and variegated, dominantly red beds of clay and sandstone in north-central Montana.
White River formation (Phanerozoic | Cenozoic | Tertiary)
White River formation: Light-colored clay with minor beds of sandstone and local beds of nodular limestone.
Willow Creek formation (Phanerozoic | Cenozoic | Cretaceous-Late)
Willow Creek formation: Variegated clay and soft sandstone, chiefly maroon to chocolate brown; local lenses of purple-gray nodular limestone.
North Carolina
Beaufort Formation, Undivided (Tertiary)
Beaufort Formation, Undivided - Unnamed upper member: sand and silty clay, glauconitic, fossiliferous, and locally calcareous. Jericho Run Member: siliceous mudstone with sandstone lenses, thin bedded; basal phosphatic pebble conglomerate.
Cape Fear Formation (Cretaceous)
Cape Fear Formation - sandstone and sandy mudstone, yellowish gray to bluish gray, mottled red to yellowish orange, indurated, graded and laterally continuos bedding, blocky clay, faint cross-bedding, feldspar and mica common.
Middendorf Formation (Cretaceous)
Middendorf Formation - sand, sandstone, and mudstone, gray to pale gray with an orange cast, mottled; clay balls and iron-cemented concretions common, beds laterally discontinuous, cross-bedding common.
Newark Supergroup, Chatham Group; Chatham Group, Undivided (Triassic)
Chatham Group, Undivided - conglomerate, fanglomerate, sandstone, and mudstone. Conglomerate and fanglomerate shown by pattern.
Newark Supergroup, Chatham Group; Cumnock Formation (Triassic)
Cumnock Formation - sandstone and mudstone, gray to black; coal beds and carbonaceous shale. Grades into Pekin and Sanford formations.
Newark Supergroup, Chatham Group; Pekin Formation (Triassic)
Pekin Formation - conglomerate, sandstone, and mudstone.
Newark Supergroup, Chatham Group; Sanford Formation (Triassic)
Sanford Formation - conglomerate, fanglomerate, sandstone, and mudstone.
Newark Supergroup, Dan River Group; Cow Branch Formation (Triassic)
Cow Branch Formation - mudstone with minor sandstone, gray, laterally-continuous bedding. Intertongues with Stoneville and Pine Hall formations.
Newark Supergroup, Dan River Group; Dan River Group, Undivided (Triassic)
Dan River Group, Undivided - basin-margin conglomerate and sandstone, red to brown, interfingering with basin-center sandstone and mudstone, green to brown. Conglomerate shown by pattern.
Newark Supergroup, Dan River Group; Pine Hall Formation (Triassic)
Pine Hall Formation - sandstone, mudstone, and conglomerate, yellowish orange to brown.
Newark Supergroup, Dan River Group; Stoneville Formation (Triassic)
Stoneville Formation - conglomerate, sandstone, and mudstone, lenticular and laterally-gradational bedding.
Ocoee Supergroup, Great Smokey Group; Rich Butt Sandstone (Late Proterozoic)
Rich Butt Sandstone - feldspathic; interbedded with dark argillaceous layers and laminae. Stratigraphic position uncertain.
Ocoee Supergroup, Snowbird Group; Roaring Fork Sandstone (Late Proterozoic)
Roaring Fork Sandstone - greenish gray, fine to medium grained, locally cross-bedded, metamorphosed; interbedded metasiltstone and phyllite.
Rome Formation (Cambrian)
Rome Formation - shale and siltstone, variegated red to brown; interbedded fine-grained sandstone and shaly dolomite.
Terrace Deposits and Upland Sediment (Tertiary)
Terrace Deposits and Upland Sediment - gravel, clayey sand, and sand, minor iron-oxide cemented sandstone.
North Dakota
Bullion Creek Formation (Phanerozoic | Cenozoic | Tertiary | Paleocene)
Yellow-brown silt, sand, clay, sandstone, and lignite; river, lake, and swamp sediment; as thick as 200 meters (600 feet).
Cannonball Formation (Phanerozoic | Cenozoic | Tertiary | Paleocene)
Olive-brown sand, shale, and sandstone; marine shoreline and offshore sediment; as thick as 120 meters (400 feet).
Fox Hills Formation (Phanerozoic | Mesozoic | Cretaceous-Late)
Olive-brown sand, shale, and sandstone; marine shoreline and offshore sediment; as thick as 120 meters (400 feet).
Golden Valley Formation (Phanerozoic | Cenozoic | Tertiary | Paleocene Eocene)
Upper member: Yellow-brown micaceous sandstone, sand, silt, and clay; fluvial sediment; as thick as 60 meters (200 feet). Lower member: White or yellow clay, silt, and sand; a weatering zone developed on underlying unit; as thick as 20 meters (65 feet).
Hell Creek Formation (Phanerozoic | Mesozoic | Cretaceous-Late)
Gray sand, silt, clay, and sandstone; river sediment; as thick as 150 meters (500 feet).
Ludlow Formation (Phanerozoic | Cenozoic | Tertiary | Paleocene)
Gray-brown and yellow-brown silt, sand, clay and sandstone, and lignite; river, lake, and swamp sediment; as thick as 100 meters (300 feet).
Sentinel Butte Formation (Phanerozoic | Cenozoic | Tertiary | Paleocene)
Gray-brown silt, sand, clay, sandstone, and lignite; river, lake, and swamp sediment; as thick as 200 meters (600 feet).
Slope Formation (Phanerozoic | Cenozoic | Tertiary | Paleocene)
Gray-brown and yellow-brown silt, sand, clay, sandstone, and lignite; river, lake, and swamp sediment; as thick as 100 meters (300 feet).
Upper and Middle Tertiary Rock, Undivided (Phanerozoic | Cenozoic | Tertiary | Miocene Pliocene)
Butte caprock consisting of fluvial or lacustrine sandstone or limestone of Oligocene, Miocene, or Pliocene age; may include the White River Group in some areas; as thick as 120 meters (400 feet).
Nebraska
Admire Group (Phanerozoic | Paleozoic | Permian)
Shale and interbedded limestone. Shale is dark gray to light gray, brown, red, or green, sandy, calcareous, and fossiliferous. Interbedded dark- to light-gray, very thin to medium bedded, argillaceous, very fossiliferous limestone beds. Near top of unit a fine-grained, micaceous sandstone bed underlies a stromatolite limestone bed which has distinctive lobate bedding. Approx. max thickness 150 ft
Carlile Shale (Phanerozoic | Mesozoic | Cretaceous-Late)
Shale, limestone, and sandstone. At top, locally 5 feet of gray to pale-yellowish brown siltstone or very fine grained sandstone. Upper 200 feet of shale is drak gray to medium gray; locally contains ironstone concretions, and interbedded with thin siltstone. Lower 80 feet of shale is medium gray, calcareous, and contains many very thin bedded, fossiliferous, shaly limestone and calcareous shale layers. Approx. max thickness 300 ft.
Dakota Group (Phanerozoic | Mesozoic | Cretaceous-Early)
Upper part is white, light-gray, brownish-gray, yellow, redish-brown, and red sandstone and shale. Sandstone is very fine to coarse grained, friable, micaeous, crossbedded, and lenticular; locally contains gravel near base. contains numerous zones of ironstone and siltstone concretions of variable thickness. Middle part is light-gray, yellow, red brown and dark-gray, sandy carbonaceous shale; commonly contains a zone of concretions near top. Lower part is sandstone similar to that in upper except there are zones of siderite concretions and, locally a basal zone of chert pebbles. Approx. max thickness 600 ft.
Fox Hills Formation (Phanerozoic | Mesozoic | Cretaceous-Late)
Consists of fossiliferous, gray, ferruginous and yellowish fine-grained sandstone, arenaceous clays and a few interbeds of gray to brown sandy shale and coal totaling 172 ft thick at that section. Estimated thickness 500 ft.
Greenhorn Limestone and Graneros Shale (Phanerozoic | Mesozoic | Cretaceous-Late)
Greenhorn Limestone- medium- to light-gray limestone interbedded with argillaceous limestone, marl and calcareous shale; contains Inoceramus fossils. Upper and lower contacts gradational. Approx. max thickness 30 ft. Graneros Shale- medium- to dark-gray, partly calcareous shale. Interbeds of siltstone, sandstone, and carbonaceous shale, and thin bentonite layers in upper part. Approx. max thickness 60 ft.
Ogallala Group or Formation (Phanerozoic | Cenozoic | Tertiary | Miocene)
Silt, sand, sandstone, gravel and conglomerate. Predominantly interfingered fine- to coarse grained, poorly sorted, arkosic, fluvial deposits of light-gray, light-olive-gray, and grayish-green calcareous silt and sand, and locally poorly consolidated conglomerate, sandstone, and siltstone.
Wabaunsee Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Virgilian])
Shale, sandstone, and interbedded limestone. Shale is light gray to dark gray, greenish gray, red, or black; contains very thin layers of siltstone; locally very fossiliferous, carbonaceous. Sandstone is brownish gray to yellowish gray, or gray, argillaceous , and micaceous. Limestone is dark gray to medium gray, yellowish gray, thin bedded to thick bedded; very fossiliferous. Contains coal beds less than 1 ft. thick. Approx. max thickness 300 ft
New Hampshire
Fitch and Clough Formations, undivided (Silurian)
Fitch and Clough Formations, undivided.
New Jersey
Bellvale Sandstone (Middle Devonian)
Bellvale Sandstone (Bellvale Flags of Darton, 1894; Willard, 1937) - Upper beds are grayish-red to grayish-purple sandstone containing quartz pebbles as large as 3 cm (1.2 in) in diameter. Lower beds are light-olive-gray- to yellowish-gray- and greenish-black-weathering, medium-gray to medium-bluish-gray very thin to very thick bedded siltstone and sandstone cross-bedded, graded and interbedded with black to dark-gray shale that is locally fossiliferous. More sandstone in upper beds becomes finer downward. Lower contact conformable and placed where beds thicken and volume of shale and siltstone are about equal. The unit is 535 to 610 m (1,750-2,000 ft) thick.
Berkshire Valley and Poxono Island Formations, undivided (Upper Silurian)
Berkshire Valley and Poxono Island Formations, undivided - Thickness ranges from 76 m (250 ft) at Greenwood Lake to 122 m (400 ft) in Longwood Valley. Berkshire Valley Formation (Barnett, 1970) - Commonly yellowish-gray weathering, medium-gray to pinkish-gray, very thin to thin-bedded fossiliferous limestone interbedded with gray to greenish-gray calcareous siltstone and silty dolomite, medium-gray to light-gray dolomite conglomerate, and grayish-black, thinly laminated shale. Lower contact conformable. Thickness ranges from 27 to 38 m (90-125 ft) thick. Poxono Island Formation, (White, 1882; Barnett, 1970) - Very thin to medium-bedded sequence of medium-gray, greenish-gray, or yellowish-gray, mud-cracked dolomite; light-green, pitted, medium-grained calcareous sandstone, siltstone, and edgewise conglomerate containing gray dolomite; and quartz-pebble conglomerate containing angular to subangular pebbles as much as 2 cm (0.8 in.) long. Interbedded grayish-green shales at lower contact are transitional into underlying Longwood Shale. Thickness ranges from 49 to 84 m (160-275 ft) thick.
Bloomsburg Red Beds (Upper Silurian)
Bloomsburg Red Beds (White, 1883) (High Falls Shale of previous usage) - Grayish-red, thin- to thick-bedded, poorly to moderately well sorted, massive siltstone, sandstone, and local quartz-pebble conglomerate containing local planar to trough crossbedded laminations. Conglomerate consists of matrix-supported quartz pebbles in grayish-red, fine-grained sandstone matrix. Locally, near base of unit, is greenish-gray, light-gray, or grayish-orange, massive, planar tabular to trough crossbedded quartz sandstone to siltstone with subrounded grains. Lower part of formation marked by several upward-fining sequences of light-gray sandstone grading through grayish-red, fine-grained sandstone and siltstone to grayish-red, mudcracked siltstone and mudstone. Each sequence is 1 to 3 m (3-10 ft) thick. Lower contact placed at bottom of lowermost red sandstone. Thickness approximately 460 m (1,510 ft).
Boonton Formation (Lower Jurassic)
Boonton Formation (Olsen, 1980) - Reddish-brown to brownish-purple, fine-grained sandstone, siltstone, and mudstone; sandstone commonly micaceous, interbedded with siltstone and mudstone in fining-upward sequences mostly 1.5 to 4 m (5-13 ft) thick. Red, gray and brownish-purple siltstone and black, blocky, partly dolomitic siltstone and shale common in lower part. Irregular mudcracks, symmetrical ripple marks, and burrows, as well as gypsum, glauberite, and halite pseudomorphs are abundant in red mudstone and siltstone. Gray, fine-grained sandstone may have carbonized plant remains and reptile footprints in middle and upper parts of unit. Near Morristown, beds of quartz-pebble conglomerate (unit Jbcq) as much as 0.5 m (1.6 ft) thick interfinger with beds of sandstone, siltstone, and shale. Northeast of Boonton, beds of quartz-pebble conglomerate (not mapped separately as Jbcq) occur locally with conglomerate containing abundant clasts of gneiss and granite in matrix of reddish-brown sandstone and siltstone. Maximum thickness is about 500 m (1,640 ft).
Coeymans Formation, Kalkberg Limestone, Coeymans Limestone, Manlius Limestone, undivided (Lower Devonian)
Coeymans Formation, Kalkberg Limestone, Coeymans Limestone, Manlius Limestone, undivided - At New York border consists of fine-grained, chert-bearing, argillaceous limestone (Kalkberg Limestone) grading downward through coarse-grained limestone (Coeymans Limestone) into fine-grained limestone (Manlius Limestone). Toward southwest these units grade into fine- to coarse-grained limestone with a marked increase in quartz sand that comprises the Coeymans Formation (Epstein and others, 1967). Total thickness 27 m (90 ft). Coeymans Formation (Epstein and others, 1967) - Medium-light-gray, fine- to coarse-grained calcareous sandstone and medium-gray, fine- to coarse-grained, medium- to thick-bedded, locally irregularly-bedded, argillaceous to arenaceous limestone containing lenses of quartz sand and nodules of black chert. Grades downward into medium-gray, fine-grained, argillaceous and arenaceous limestone containing local beds of fine- to coarse-grained pebbly calcareous sandstone. Local bioherms consisting of light-gray to light-pinkish-gray, coarse-grained to very coarse biogenic limestone are unbedded and have sharp boundaries. Lower contact of unit abrupt. Formation thickness varies from 11 m (35 ft) in northeast to 24 m (80 ft) in southwest. Kalkberg Limestone (Chadwick, 1908) - Medium-gray-weathering, medium-dark-gray, fine-grained, very thin to massively bedded fossiliferous limestone. Grades downward into fine- to medium-grained, thin-bedded, fossiliferous argillaceous limestone containing nodules and lenses of dark-gray chert. Grades to the southwest into calcareous and arenaceous rocks of the upper part of the Coeymans Formation near Wallpack Center. Lower contact placed at base of lowest black chert. Approximately 12 m (40 ft) thick. Coeymans Limestone (Clarke and Schuchert, 1899) - Medium-gray weathering, medium-dark-gray, fine-to-coarse-grained, medium- to massively bedded fossiliferous limestone and local argillaceous limestone lenses. Unit is approximately 9 m (30 ft) thick. Between Duttonville and Millville, grades into biohermal and nonbiohermal facies of medium- to coarse-grained limestone of Coeymans Formation of Epstein and others (1967). Manlius Limestone (Vanuxem, 1840) - Medium-gray weathering, medium-dark- to dark-gray, very fine to fine-grained, unevenly bedded fossiliferous limestone. Some local medium-grained limestone, yellowish-gray shale partings and biostromes. Near Hainesville, unit grades into lower part of Coeymans Formation. Lower contact abrupt and placed at top of uppermost very fine grained argillaceous limestone. Thickness approximately 11 m (35 ft).
Feltville Formation (Lower Jurassic)
Feltville Formation (Olsen, 1980) - Interbedded brownish-red to light-grayish-red, fine- to coarse-grained sandstone, gray and black, coarse siltstone in upward-fining cycles, and silty mudstone. Fine-grained sandstone and siltstone are moderately well sorted, commonly cross-laminated, and have 15 percent or more feldspar; interbedded with brownish-red, indistinctly laminated, bioturbated calcareous mudstone. Thermally metamorphosed into hornfels where in contact with Preakness Basalt. Near the base are two thin, laterally continuous beds of black, carbonaceous limestone and gray, calcareous siltstone, each up to 3 m (10 ft) thick. These contain abundant fish, reptile, anthropod, and diagnostic plant fossils. Three or four, thin, gray to black siltstone and mudstone sequences occur in upper part of unit. Near Oakland, subrounded pebbles to cobbles of quartzite and quartz in a red siltstone and sandstone matrix (Jfc) interfinger with sandstone and siltstone of the Feltville Formation. Maximum thickness about 155 m (510 ft).
Feltville Formation (Lower Jurassic)
Feltville Formation - Mostly fine-grained, feldspathic sandstone, coarse siltstone, and silty mudstone, brownish-red to light-grayish-red. Fine-grained sandstone is moderately well sorted, cross laminated, and contains 15 percent or more feldspar; interbedded with mudstone, indistinctly laminated, bioturbated, and calcareous in places. A thin bed (0-2 m (0-7 ft) thick) of black, microlaminated carbonaceous limestone and gray calcareous mudstone occurs near the base and contains fish and plant fossils, and thermally mature hydrocarbons. Thickness of unit in the Sand Brook syncline is about 155 m (509 ft).
Feltville Formation Conglomerate and Sandstone facies (Lower Jurassic)
Feltville Formation Conglomerate and Sandstone facies - Near Oakland, subrounded pebbles to cobbles of quartzite and quartz in a red siltstone and sandstone matrix (Jfc) interfinger with sandstone and siltstone of the Feltville Formation.
Hardyston Quartzite (Lower Cambrian)
Hardyston Quartzite (Lower Cambrian) (Wolff and Brooks, 1898) - Light- to medium-gray and bluish-gray conglomeratic sandstone. Varies from pebble conglomerate, to fine-grained, well-cemented quartzite, to arkosic or dolomitic sandstone. Conglomerate contains subangular to subrounded white quartz pebbles up to 2.5 cm (1 in.). Lower contact unconformable. About 0 to 9 m (1-30 ft) thick.
Hardyston Quartzite (Lower Cambrian)
Hardyston Quartzite (Wolff and Brooks, 1898) - Medium- to light-gray, fine- to coarse-grained, medium- to thick-bedded quartzite, arkosic sandstone and dolomitic sandstone. Basal pebble to cobble conglomerate typically contains clasts of local basement affinities. Contains fragments of the trilobite Olenellus thompsoni of Early Cambrian age. Thickness approximately 0.5 to 62 m (1.6-200 ft).
High Point Member (Upper Ordovician)
High Point Member (Drake, 1991) - Medium-dark-gray, thin-bedded shale, siltstone and fine-grained sandstone, containing turbidite sequences Tbcde to Tcde of Bouma (1962). Interbedded with less abundant, light-yellowish-gray-weathering, medium-gray to medium-dark-gray, medium-grained, medium- to thick-bedded and massive, quartz- and calcareous-cemented quartz sandstone containing rip-ups of medium- to dark-gray shale and siltstone that commonly consist of Bouma (1962) turbidite sequences Tab to Ta. Restricted to northeast section of Martinsburg outcrop belt. Thermally metamorphosed near intrusive bodies. Grades along strike to the southwest into Ramseyburg Member by decrease in average grain size, absence of shale rip-ups, and lack of siliceous cement. Lower contact gradational and placed at base of lowermost thick-bedded graywacke or amalgamated graywacke containing shale rip-ups. Unit assigned to Orthograptus ruedemanni zone to Climacograptus spiniferus zone of Riva (1969, 1974) using graptolites collected by Parris and Cruikshank (1992). Thickness ranges from 0 to 1,370 m (0-4,500 ft).
Jutland Klippe Sequence, undifferentiated (Middle Ordovician to Upper Cambrian?)
Jutland Klippe Sequence, undifferentiated - Rocks of the Jutland klippe sequence occur in six isolated fragments of the Jutland klippe east of Jutland and two fragments of the Peapack klippe along the Peapack-Ralston fault in the New Jersey Highlands hinterland. The sequence is largely varicolored shale and sandstone, but contains lesser amounts of limestone, dolomite and pebble conglomerate. Lash and Drake (1984) correlate this sequence with the accretionary prism deposits of the Greenwich slice of the Hamburg klippe in eastern Pennsylvania. Rocks of the Jutland klippe sequence were folded and thrust over rocks of the Kittatinny Valley sequence during the Taconic orogeny and then were deformed during the Alleghanian orogeny and again during Mesozoic rifting of eastern North America.
Jutland Klippe Sequence Unit A (lower Middle Ordovician to Upper Cambrian)
Jutland Klippe Sequence Unit A of Perissoratis and others (1979) - Interbedded red, green, and tan shale, sandstone, and dark-gray, aphanitic to fine-grained limestone, which contains floating quartz-sand grains. Grades downward through interbedded sequence of red, green and brown shale to medium-gray to brown, fine- to coarse-grained sandstone and quartz-pebble conglomerate. Lower beds are dark-gray shale and siltstone containing minor dark-gray, aphanitic to fine-grained, medium-bedded limestone. Lower contact is a fault. Contains graptolites in the span of Anisograptus to Isograptus caduceus of Berry (1968) (Perissoratis and others, 1979) and conodonts of the Cordylodus proavus to Paroistodus proteus faunas of the North Atlantic Realm. Thickness is unknown.
Jutland Klippe Sequence Unit B (Middle Ordovician)
Jutland Klippe Sequence Unit B of Perissoratis and others (1979) - Heterogeneous sequence of interbedded red, green, tan and gray shale; interlaminated dolomite and shale; interbedded fine-grained graywacke siltstone and beds or lenses of sandstone; light-gray to pale-pinkish-gray quartzite; and interbedded fine-grained, thin-bedded limestone and red and green shale. Limestone locally resembles an intraformational conglomerate because it is disrupted, boudinaged, and surrounded by shale beds. Lower contact gradational and within interbedded sequence of thin- to medium-bedded sandstone, siltstone, and limestone. Perissoratis and others (1979) placed this contact at boundary between graptolite faunas Isograptus caduceus and Paraglossograptus etheridgei of Berry (1968). The youngest graptolites occur within Climacograptus bicornis zone of Berry (1968). Some shale beds contain conodonts (Ethington and others, 1958; Karklins and Repetski, 1989) and brachiopod fragments. Carbonate and pelitic rocks locally contain conodonts of Prioniodus triangularis to Pygodus anserinus faunas of North Atlantic Realm. Thickness varies due to structural complexity, but may be about 460 to 550 m (1,500-1,800 ft).
Kanouse and Esopus Formations and Connelly Conglomerate, undivided (Lower Devonian)
Kanouse and Esopus Formations and Connelly Conglomerate, undivided - Kanouse Sandstone (Kummel, 1908) - Medium-gray, light-brown, and grayish-red, fine- to coarse-grained, thin- to thick-bedded sparsely fossiliferous sandstone and pebble conglomerate. Basal conglomerate beds are interbedded with siltstone similar to the upper part of the Esopus Formation and contain well-sorted, subangular to subrounded, gray and white quartz pebbles less than 1 cm (0.4 in.) long. Lower contact gradational. About 14 m (46 ft) thick. Esopus Formation - (Vanuxem, 1842; Boucot, 1959) - Light- to dark-gray, laminated to thin-bedded siltstone interbedded with dark-gray to black mudstone, dusky-blue sandstone and siltstone, and yellowish-gray fossiliferous siltstone and sandstone. Lower contact probably conformable with the Connelly Conglomerate. The formation is about 100 m (330 ft) thick at Greenwood Lake and estimated at 55 m (180 ft) thick in Longwood Valley. Connelly Conglomerate (Chadwick, 1908) - Grayish-orange weathering, very light gray to yellowish-gray, thin-bedded quartz-pebble conglomerate. Quartz pebbles average 1 to 2 cm (0.4-0.8 in.), are subrounded to well rounded, and well sorted. The unit unconformably overlies the Berkshire Valley Formation. About 11 m (36 ft) thick.
Leithsville Formation (Middle and Lower Cambrian)
Leithsville Formation (Middle and Lower Cambrian) (Wherry, 1909) - Light- to dark-gray and lightolive-gray, fine- to medium-grained, thin- to medium-bedded dolomite. Grades downward through medium-gray, grayish-yellow, or pinkish-gray dolomite and dolomitic sandstone, siltstone and shale to medium-gray, medium-grained, medium-bedded dolomite containing quartz sand grains as stringers and lenses near the base. Lower contact gradational. Thickness ranges from 0 to 56 m (0-185 ft) due to erosion.
Leithsville Formation (Middle and Lower Cambrian)
Leithsville Formation (Wherry, 1909) - Thin- to thick-bedded dolomite containing subordinate siliciclastic rocks. Upper part is medium- to medium-dark-gray, fine- to medium-grained, pitted, friable, mottled and massive dolomite. Middle part is medium-gray, stylolitic, fine-grained, thin- to medium-bedded dolomite that is interbedded with shaly dolomite and, less commonly, vari-colored quartz sandstone, siltstone, and shale. Lower part is medium-gray, medium-grained, medium-bedded dolomite containing quartz-sand grains in stringers and lenses near the contact with the Hardyston Quartzite. Archaeocyathids of Early Cambrian age suggest an intraformational disconformity separating rocks of Middle and Early Cambrian age (Palmer and Rozanov, 1976). Thickness approximately 305 m (1,000 ft).
Lockatong Formation (Upper Triassic)
Lockatong Formation (Kummel, 1897) - Cyclically-deposited sequences consisting of light- to dark-gray, greenish-gray, and black, dolomitic or analcime-bearing silty argillite, laminated mudstone, silty to calcareous, argillaceous, very-fine-grained pyritic sandstone and siltstone, and minor silty limestone (Trl). Grayish-red, grayish-purple, and dark-brownish-red sequences (Trlr) common in upper half. Two types of cycles are recognized: detrital and chemical. Detrital cycles average 5.2 m (17 ft) thick and consist of basal, argillaceous, very fine grained sandstone to coarse siltstone; medial, dark-gray to black, laminated siltstone, silty mudstone, or silty limestone; and upper, light- to dark-gray, silty to dolomitic or analcime-rich mudstone, argillitic siltstone, or very-fine-grained sandstone. Chemical cycles are similar to detrital cycles, but thinner, averaging 3.2 m (10.5 ft). Cycles in northern Newark basin are thinner and have arkosic sandstone in lower and upper parts. Upper part of formation in northern basin composed mostly of light-gray to light-pinkish-gray or light-brown, coarse- to fine-grained, thick- to massive-bedded arkosic sandstone (Trla). Thermally metamorphosed into hornfels where intruded by diabase (Jd). Interfingers laterally and gradationally with quartz sandstone and conglomerate (Trls) and quartzite conglomerate (Trlcq) near Triassic border fault in southwestern area of map. Maximum thickness of Lockatong Formation about 1,070 m (3,510 ft).
Lockatong Formation (Upper Triassic)
Lockatong Formation - Predominantly cyclic lacustrine sequences of silty, dolomitic or analcime-bearing argillite; laminated mudstone; silty to calcareous, argillaceous very fine grained sandstone and pyritic siltstone; and minor silty limestone, mostly light- to dark-gray, greenishgray, and black. Grayish-red, grayish-purple, and dark-brownish-red sequences (Trlr) occur in some places, especially in upper half. Two types of cycles are recognized: freshwater-lake (detrital) and alkaline-lake (chemical) cycles. Freshwater-lake cycles average 5.2 m (17 ft) thick. They consist of basal, transgressive, fluvial to lake-margin deposits that are argillaceous, very fine grained sandstone to coarse siltstone with indistinct lamination, planar or cross lamination, or are disrupted by convolute bedding, desiccation cracks, root casts, soil-ped casts, and tubes. Medial lake-bottom deposits are laminated siltstones, silty mudstones, or silty limestones that are dark gray to black with calcite laminae and grains and lenses, or streaks of pyrite; fossils are common, including fish scales and articulated fish, conchostracans, plants, spores, and pollen. Upper regressive lake margin, playa lake, and mudflat deposits are light- to dark-gray silty mudstone to argillitic siltstone or very fine grained sandstone, mostly thick bedded to massive, with desiccation cracks, intraformational breccias, faint wavy laminations, burrows, euhedral pyrite grains, and dolomite or calcite specks. Alkaline-lake cycles are similar to freshwater-lake cycles, but are thinner, averaging 3 m (10 ft), have fewer fossils (mainly conchostracans), and commonly have red beds, extensive desiccation features, and abundant analcime and dolomite specks in the upper parts of cycles. Thickness near Byram is about 1,070 m (3,510 ft). The formation thins to the southeast and northeast; thickness near Princeton is less than 700 m (2,297 ft).
Lockatong Formation - Conglomerate facies (Upper Triassic)
Lockatong Formation Sandstone and Conglomerate Sandstone facies - Unit Trla interfingers laterally and gradationally with quartz sandstone and conglomerate (Trls) and quartzite conglomerate (Trlcq) near Triassic border fault in southwestern area of map.
Lockatong Formation red bed (Upper Triassic)
Lockatong Formation red bed - Cyclically-deposited sequences consisting of light- to dark-gray, greenish-gray, and black, dolomitic or analcime-bearing silty argillite, laminated mudstone, silty to calcareous, argillaceous, very-fine-grained pyritic sandstone and siltstone, and minor silty limestone (Trl). Grayish-red, grayish-purple, and dark-brownish-red sequences (Trlr) common in upper half.
Lockatong Formation red bed (Upper Triassic)
Lockatong Formation red bed - Predominantly cyclic lacustrine sequences of silty, dolomitic or analcime-bearing argillite; laminated mudstone; silty to calcareous, argillaceous very fine grained sandstone and pyritic siltstone; and minor silty limestone, mostly light- to dark-gray, greenishgray, and black. Grayish-red, grayish-purple, and dark-brownish-red sequences (Trlr) occur in some places, especially in upper half. Two types of cycles are recognized: freshwater-lake (detrital) and alkaline-lake (chemical) cycles. Freshwater-lake cycles average 5.2 m (17 ft) thick. They consist of basal, transgressive, fluvial to lake-margin deposits that are argillaceous, very fine grained sandstone to coarse siltstone with indistinct lamination, planar or cross lamination, or are disrupted by convolute bedding, desiccation cracks, root casts, soil-ped casts, and tubes. Medial lake-bottom deposits are laminated siltstones, silty mudstones, or silty limestones that are dark gray to black with calcite laminae and grains and lenses, or streaks of pyrite; fossils are common, including fish scales and articulated fish, conchostracans, plants, spores, and pollen. Upper regressive lake margin, playa lake, and mudflat deposits are light- to dark-gray silty mudstone to argillitic siltstone or very fine grained sandstone, mostly thick bedded to massive, with desiccation cracks, intraformational breccias, faint wavy laminations, burrows, euhedral pyrite grains, and dolomite or calcite specks. Alkaline-lake cycles are similar to freshwater-lake cycles, but are thinner, averaging 3 m (10 ft), have fewer fossils (mainly conchostracans), and commonly have red beds, extensive desiccation features, and abundant analcime and dolomite specks in the upper parts of cycles. Thickness near Byram is about 1,070 m (3,510 ft). The formation thins to the southeast and northeast; thickness near Princeton is less than 700 m (2,297 ft).
Lockatong Formation - Sandstone and Conglomerate facies (Upper Triassic)
Sandstone and Conglomerate Sandstone facies - Unit Trla interfingers laterally and gradationally with quartz sandstone and conglomerate (Trls) and quartzite conglomerate (Trlcq) near Triassic border fault in southwestern area of map.
Longwood Shale (Middle (?) and Upper Silurian)
Longwood Shale (Darton, 1894) - Dark-reddish-brown, thin- to very thick bedded shale interbedded with cross-bedded, very dark red, very thin to thin-bedded sandstone and siltstone. Lower contact conformable. About 100 m (330 ft) thick.
Marcellus Shale (Middle Devonian)
Marcellus Shale (Vanuxem, 1840) - Medium-gray weathering, dark-gray to grayish-black, thin- to thick-bedded, fossiliferous, fissile and limonite-stained locally arenaceous shale. Lower contact grades downward over 12 m (40 ft) from black shale through limy shale, into silty limestone of the Buttermilk Falls Limestone (documented in drill core data of Fletcher and Woodrow, 1970). Approximately 274 m (900 ft) thick.
Oriskany Group, undivided (Lower Devonian)
Oriskany Group, undivided (Willard, 1938) - Thickness ranges from 38 m (125 ft) in southwest to 52 m (170 ft) in northeast. Ridgely Sandstone (Swartz and others, 1913) - White-weathering, medium-gray, medium- to thick-bedded, carbonate-cemented quartz-pebble conglomerate and coarse quartz sandstone, which contain abundant brachiopods. Moderately well sorted, subrounded sand gains. Unit thins northeastward and pinches out at Peters Valley. Lower contact abrupt. Thickness ranges from 0 to 10 m (0-32 ft). Shriver Chert (Swartz and others, 1913) - Medium- to dark-gray-weathering, black to dark-gray, medium-to-thick-bedded siltstone and shale containing interbedded black chert and local chert-bearing limestone. Present only in southwestern part of outcrop area where lower contact is gradational with silty limestone of Glenarie Formation. Thickness ranges from 0 to 9 m (0-30 ft). Glenarie Formation (Chadwick, 1908) - Medium-gray-weathering, medium- to dark-gray, fine-grained, thin- to medium-bedded, fossiliferous, silty limestone, and local chert lenses. Unit thickens to northeast. Lower contact probably gradational. Thickness ranges from 17 to 52 m (55-170 ft).
Passaic Formation (Lower Jurassic and Upper Triassic)
Passaic Formation - Predominantly red beds consisting of argillaceous siltstone; silty mudstone; argillaceous, very fine grained sandstone; and shale; mostly reddish-brown to brownish-purple, and grayish-red. Red beds occur typically in 3- to 7-m (10- to 23-ft-)-thick, cyclic playa-lake-mudflat sequences and fining-upward fluvial sequences. Lamination is commonly indistinct due to burrowing, desiccation, and paleosol formation. Where layering is preserved, most bedforms are wavy parallel lamination and trough and climbing-ripple cross lamination. Calcite- or dolomite-filled vugs and flattened cavities, mostly 0.5 to 0.2 mm (0.02-0.08 in) across, occur mostly in the lower half. Sand-filled burrows, 2 to 5 mm (0.08-0.2 in) in diameter, are prevalent in the upper two-thirds of the unit. Desiccation cracks, intraformational breccias, and curled silt laminae are abundant in the lower half. Lake cycles, mostly 2 to 5 m (7-16 ft) thick, have a basal, greenish-gray, argillaceous siltstone; a medial, dark-gray to black, pyritic, carbonaceous, fossiliferous, and, in places, calcareous lake-bottom fissile mudstone or siltstone; and an upper thick-bedded, gray to reddish and purplish-gray argillaceous siltstone with desiccation cracks, intraformational breccias, burrows, and mineralized vugs. Thickness of the formation between Sourland Mountain and Sand Brook syncline is about 3,500 m (11,483 ft).
Passaic Formation Conglomerate and Sandstone facies (Lower Jurassic and Upper Triassic)
Passaic Formation Conglomerate and Sandstone facies - Conglomeratic sandstone (JTrpsc) is brownish-red pebble conglomerate, medium- to coarse-grained, feldspathic sandstone and micaceous siltstone; unit is planar to low-angle trough cross laminated, burrowed, and contains local pebble layers. Unit forms upward-fining sequences 0.5 to 2.5 m (1.6-8 ft) thick. Conglomeratic sandstone thickness exceeds 800 m (2,625 ft).
Passaic Formation gray bed (Lower Jurassic and Upper Triassic)
Passaic Formation gray bed - Upper Triassic gray lake deposits (Trpg) consist of gray to black silty mudstone, gray and greenish- to purplish-gray argillaceous siltstone, black shale, and medium- to dark-gray, argillaceous, fine-grained sandstone and are abundant in the lower half of the Passaic Formation. Gray lakebeds occur in groups of two to five cycles although they also occur as single cycles in some parts of the formation. Several lakebed sequences consisting of one or two thick groups of drab-colored beds as much as 30 m (98 ft) thick or more can be traced over tens of kilometers. Many gray-bed sequences are locally correlated within fault blocks; some can be correlated across major faults or intrusive rock units. Thickness of the (entire Passaic) formation between Sourland Mountain and Sand Brook syncline is about 3,500 m (11,483 ft).
Passaic Formation Limestone-clast Conglomerate facies (Lower Jurassic and Upper Triassic)
Passaic Formation Limestone-clast Conglomerate facies - Limestone conglomerate unit (JTrpcl) is medium-bedded to massive, pebble to boulder conglomerate. Clasts are subangular dolomitic limestone in matrix of brownish- to purplish-red sandstone to mudstone; matrix weathers light-gray to white near faults. Maximum thickness unknown.
Passaic Formation Mudstone facies (Lower Jurassic and Upper Triassic)
Passaic Formation Mudstone facies - Sandy mudstone (JTrpms) is reddish-brown to brownish-red, massive, silty to sandy mudstone and siltstone, which are bioturbated, ripple cross-laminated and interbedded with lenticular sandstone. To southwest where similar lithologic units also occur, they have not been mapped separately, but have been included in undivided unit JTrp.
Passaic Formation Quatzite-clast Conglomerate facies (Lower Jurassic and Upper Triassic)
Passaic Formation Quartzite-clast Conglomerate facies - Quartzite conglomerate unit (JTrpcq) is reddish-brown pebble conglomerate, pebbly sandstone, and sandstone, in upward-fining sequences 1 to 2 m (3-6 ft) thick. Clasts are subangular to subrounded, quartz and quartzite in sandstone matrix. Sandstone is medium to coarse grained, feldspathic (up to 20 percent feldspar), and locally contains pebble and cobble layers. Conglomerate thickness exceeds 850 m (2,790 ft).
Passaic Formation Sandstone and Siltstone facies (Lower Jurassic and Upper Triassic)
Passaic Formation Sandstone and Siltstone facies - Sandstone (JTrps) is interbedded grayish-red to brownish-red, medium- to fine-grained, medium- to thick-bedded sandstone and brownish-to-purplish-red coarse-grained siltstone; unit is planar to ripple cross-laminated, fissile, locally calcareous, containing desiccation cracks and root casts. Upward-fining cycles are 1.8 to 4.6 m (6-15 ft) thick. Sandstone beds are coarser and thicker near conglomerate units (JTrpcq, JTrpcl). Maximum thickness about 1,100 m (3,610 ft).
Poxono Island Formation (Upper Silurian)
Poxono Island Formation (White, 1882) - Greenish-gray, finely crystalline to aphanitic, thin- to medium-bedded, flaggy dolomite containing discontinuous lenses of disseminated, rounded quartz grains. Some local quartz sandstone beds and argillaceous dolomite. Lower contact gradational (Epstein, 1973). Formation poorly exposed; located by drill data. Thickness estimated at 183 m (600 ft) from well data.
Rondout and Decker Formations, undivided (Lower Devonian and Upper Silurian)
Rondout and Decker Formations, undivided - Rondout Formation (Clarke and Schuchert, 1899) - Upper part is medium-gray weathering, medium-dark-gray, very fine to fine-grained, medium-bedded, fossiliferous, argillaceous limestone. Middle part is light-medium-gray-weathering, medium-gray, laminated to medium-bedded, argillaceous dolomite. Locally contains deep desiccation polygons. Lower part is medium-gray-weathering, medium- to dark-gray, very fine to medium-grained, medium-bedded fossiliferous limestone. Silurian-Devonian boundary placed in middle of formation (Denkler and Harris, 1988). Lower contact abrupt and placed at top of highest calcareous quartz sandstone. Thickness approximately 12 m (40 ft). Decker Formation (White, 1882) - Light-gray- to yellowish-gray-weathering, light- to medium-gray, calcareous quartz siltstone, sandstone, and fine-pebble conglomerate locally interbedded with fossiliferous medium-gray, medium- to coarse-grained limestone and very fine grained, thin- to medium-bedded dolomite. Lower contact gradational. Thickness varies from 15 m (50 ft) near Duttonville to 25 m (82 ft) at Wallpack Center.
Shawangunk Formation (Middle and Lower Silurian)
Shawangunk Formation (Mather, 1840; Epstein and Epstein, 1972) - Upper part is medium- to medium-dark-gray, or dark-greenish-gray, medium- to thick-bedded sandstone and pebble conglomerate having well rounded grains, some of which are limonite stained. Conglomerate consists of matrix-supported quartz and subordinate shale pebbles as long as 5 cm (2 in.) in poorly to well-sorted, planar tabular to trough crossbedded sandstone. Local black to dark-greenish-gray, thin-bedded shale near upper contact. Middle part, occurring in southwest and sporadically in northeast, is light- to medium-dark-gray, greenish-gray, interbedded thin- to medium-bedded, planar tabular to trough cross-bedded shale and sandstone. Grains are well rounded and moderately to well sorted. Contains sparse graphite flakes. Lower part is light- to medium-gray to light-olive-gray, thin- to thick-bedded quartz and feldspathic sandstone, quartzite, and quartz-pebble conglomerate, which is matrix-supported, poorly to well sorted, cross to planar bedded. Clasts are primarily quartz and sparse dark-gray argillite and black chert. Sandstone is feldspathic and locally approaches an arkose in compostion. Lower contact unconformable and, at places, is a fault of small displacement. Thickness approximately 427 m (1,400 ft).
Skunnemunk Conglomerate (Middle Devonian)
Skunnemunk Conglomerate (Darton, 1894) - Grayish-purple to grayish-red, thin- to very thick bedded, locally cross-bedded, polymictic conglomerate and sandstone containing clasts of white vein quartz, red and green quartzite and sandstone, red and gray chert, and red shale; interbedded with medium-gray, thin-bedded sandstone and greenish-gray and grayish-red, mud-cracked shale. Conglomerate and sandstone matrix is primarily hematite and microcrystalline quartz. Conglomerate cobbles range to 16.5 cm (6.5 in) long, and average cobble size increases in upper part of unit. Lower contact conformable and gradational as defined by Kummel and Weller (1902). About 915 m (3,000 ft) thick.
Stockton Formation (Upper Triassic)
Stockton Formation (Kummel, 1897) - Light-gray, light-grayishbrown, yellowish- to pinkish-gray, or violet-gray to reddish-brown, medium- to coarse-grained arkosic sandstone and reddish- to purplish-brown mudstone, silty mudstone, argillaceous siltstone, and shale. Mudstone, siltstone and shale beds thicker and more numerous in central Newark basin west of Round Valley Reservoir. Sandstones mostly planar-bedded, with scoured bases containing pebble lags and mudstone rip-ups. Unit is coarser near Newark basin border fault, where poorly exposed, reddish-brown to pinkish-white, medium- to coarse-grained, feldspathic pebbly sandstone and conglomerate (Trss) and pebble to cobble quartzite conglomerate (Trscq). Maximum thickness of formation about 1,240 m (4,070 ft).
Stockton Formation Cobble Conglomerate and Sandstone facies (Upper Triassic)
Stockton Formation Cobble Conglomerate and Sandstone facies - Unit is coarser near Newark basin border fault, where poorly exposed, reddish-brown to pinkish-white, medium- to coarse-grained, feldspathic pebbly sandstone and conglomerate (Trss) and pebble to cobble quartzite conglomerate (Trscq).
Towaco Formation (Lower Jurassic)
Towaco Formation (Olsen, 1980) - Reddish-brown to brownish-purple, fine- to medium-grained micaceous sandstone, siltstone, and silty mudstone in upward-fining sequences 1 to 3 m (3-10 ft) thick. Distributed throughout formation are eight or more sequences of gray to greenish- or brownish-gray, fine-grained sandstone, siltstone and calcareous siltstone and black, microlaminated calcareous siltstone and mudstone containing diagnostic pollen, fish and dinosaur tracks. Sandstone is commonly trough cross laminated; siltstone is commonly planar laminated or bioturbated, but can be indistinctly laminated to massive. Thermally metamorphosed into hornfels where in contact with Hook Mountain Basalt. Conglomerate and conglomeratic sandstone with subrounded quartzite and quartz clasts in matrix of light-red sand to brownish-red silt (Jtc) interfingers with rocks of the Towaco Formation north and west of New Vernon. Maximum thickness is about 380 m (1,250 ft).
Towaco Formation Conglomerate and Sandstone facies (Lower Jurassic)
Towaco Formation Conglomerate and Sandstone facies - Conglomerate and conglomeratic sandstone with subrounded quartzite and quartz clasts in matrix of light-red sand to brownish-red silt (Jtc) interfingers with rocks of the Towaco Formation north and west of New Vernon.
New Mexico
Abo and Yeso Formations (Phanerozoic | Paleozoic | Permian)
Abo and Yeso Formations, undivided
Abo Formation (Phanerozoic | Paleozoic | Permian)
Abo Formation; red beds, arkosic at base, finer and more mature above; Wolfcampian; may include limestone beds of Pennsylvanian age (Virgilian) in Zuni Mountains. In Robledo Mountains the Abo may be considered a member of the Hueco Formation
Abo Formation, lower part (Phanerozoic | Paleozoic | Permian)
Lower part of Abo Formation; Wolfcampian, and in part Virgilian ?
Abo Formation, upper part (Phanerozoic | Paleozoic | Permian)
Upper part of Abo Formation; Wolfcampian
Bell Canyon Formation (Phanerozoic | Paleozoic | Permian)
Bell Canyon Formation; basin facies-sandstone, limestone, and shale; Guadalupian
Bull Canyon Formation of Chinle Group (Phanerozoic | Mesozoic | Triassic)
Bull Canyon Formation; Norian
Bursum Formation (Phanerozoic | Paleozoic | Permian)
Bursum Formation; shale, arkose, and limestone; earliest Permian
Cherry Canyon Formation (Phanerozoic | Paleozoic | Permian)
Cherry Canyon Formation; basin facies-sandstone, limestone, and shale
Chuska Sandstone (Phanerozoic | Cenozoic | Tertiary)
Chuska Sandstone; restricted to Chuska Mountains
Cliff House Sandstone (Phanerozoic | Mesozoic | Cretaceous)
Cliff House Sandstone; transgressive marine sandstone; Campanian
Cutler Formation (Phanerozoic | Paleozoic | Permian)
Cutler Formation; used in northern areas and Chama embayment only
Dakota Group (Phanerozoic | Mesozoic | Cretaceous)
Dakota Group of east-central and northeast New Mexico; in ascending order, Mesa Rica Sandstone, Pajarito Shale, and Romeroville Sandstone; includes the underlying Tucumcari Shale in Tucumcari area and Glencairn Formation in Union County. Encompasses both Upper and Lower Cretaceous rocks
Dakota Sandstone and Rio Salado Tongue of the Mancos Shale (Phanerozoic | Mesozoic | Cretaceous)
Dakota Sandstone and Rio Salado Tongue of the Mancos Shale. In northwest Socorro County locally includes overlying Tres Hermanos Formation
Entrada Sandstone (Phanerozoic | Mesozoic | Jurassic)
Entrada Sandstone, Middle Jurassic; Callovian
Fence Lake Formation (Phanerozoic | Cenozoic | Tertiary)
Fence Lake Formation; conglomerate and conglomeratic sandstone, coarse fluvial volcanoclastic sediments, minor eolian facies, and pedogenic carbonates of the southern Colorado Plateau region; Miocene
Gallup Sandstone (Phanerozoic | Mesozoic | Cretaceous)
Gallup Sandstone; generally regressive marine sandstone; Turonian
Gallup Sandstone and underlying D-Cross Tongue of Mancos Shale (Phanerozoic | Mesozoic | Cretaceous)
Gallup Sandstone and underlying D-Cross Tongue of the Mancos Shale; Turonian
Garita Creek Formation of Chinle Group (Phanerozoic | Mesozoic | Triassic)
Garita Creek Formation; Carnian
Gila Group (Phanerozoic | Cenozoic | Tertiary Quaternary)
Gila Group. Includes Mimbres Formation and several informal units in southwestern basins; Middle Pleistocene to uppermost Oligocene
Glorieta Sandstone (Phanerozoic | Paleozoic | Permian)
Glorieta Sandstone; texturally and mineralogically mature, high-silica quartz sandstone
Grayburg and Queen Fromations (Phanerozoic | Paleozoic | Permian)
Grayburg and Queen Formations; sandstone, gypsum, anhydrite, dolomite, and red mudstone; Guadalupian
Hosta Tongue of Point Lookout Sandstone (Phanerozoic | Mesozoic | Cretaceous)
Hosta Tongue of Point Lookout Sandstone; transgressive marine sandstone
Kirtland and Fruitland Formations (Phanerozoic | Mesozoic | Cretaceous)
Kirtland and Fruitland Formations; coal-bearing, coal primarily in the Fruitland; Campanian to Maastrichtian
La Ventana Tongue (Phanerozoic | Mesozoic | Cretaceous)
La Ventana Tongue of the Cliff House Sandstone
Mancos Formation and Beartooth Quartzite (Phanerozoic | Mesozoic | Cretaceous)
Mancos Formation and Beartooth Quartzite (and Sarten Sandstone); Mancos includes what was formerly referred to as Colorado Shale which in turn may include equivalents of Tres Hermanos Formation
McRae Formation (Phanerozoic | Mesozoic | Cretaceous)
McRae Formation; Engle basin - Cutter sag area; Maastrichtian
Mesaverde Group (Phanerozoic | Mesozoic | Cretaceous)
Mesaverde Group includes the Gallup Sandstone, Crevasse Canyon Formation, Point Lookout Sandstone, Menefee Formation, and Cliff House Sandstone
Moenkopi Formation (Phanerozoic | Mesozoic | Triassic)
Moenkopi Formation; Middle Triassic
Moreno Hill Formation and Atarque Sandstone (Phanerozoic | Mesozoic | Cretaceous)
Moreno Hill Formation and Atarque Sandstone; in Salt Lake coal field and extreme southern Zuni basin; Turonian
Mulatto Tongue of Mancos Shale (Phanerozoic | Mesozoic | Cretaceous)
Mulatto Tongue of Mancos Shale
Nacimiento Formation (Phanerozoic | Cenozoic | Tertiary)
Nacimiento Formation; Paleocene, San Juan Basin
Ojo Alamo Formation (Phanerozoic | Cenozoic | Tertiary)
Ojo Alamo Formation; Paleocene, San Juan Basin
Pescado Tongue of the Mancos Shale and Gallup Sandstone (Phanerozoic | Mesozoic | Cretaceous)
Pescado Tongue of the Mancos Shale and Gallup Sandstone; in Zuni Basin only. Pescado is chrono-stratigraphic equivalent of Juana Lopez Member of Mancos Shale; Turonian
Pictured Cliffs Sandstone (Phanerozoic | Mesozoic | Cretaceous)
Pictured Cliffs Sandstone; prominent cliff-forming marine sandstone
Point Lookout Sandstone (Phanerozoic | Mesozoic | Cretaceous)
Point Lookout Sandstone; regressive marine sandstone in McKinley and Sandoval Counties. The lower, Hosta Tongue, of Point Lookout is transgressive and is separated from main body by the Satan Tongue of Mancos Shale; Santonian - Campanian
Poison Canyon and Raton Fromations (Phanerozoic | Mesozoic Cenozoic | Cretaceous Tertiary)
Poison Canyon and Raton Formations; undivided
Poison Canyon Formation (Phanerozoic | Cenozoic | Tertiary)
Poison Canyon Formation; Paleocene, Raton Basin
Quartermaster Formation (Phanerozoic | Paleozoic | Permian)
Quartermaster Formation; red sandstone and siltstone; Upper Permian
Quatermaster and Rustler Formations (Phanerozoic | Paleozoic | Permian)
Quartermaster and Rustler Formations; Upper Permian
Raton Formation (Phanerozoic | Mesozoic Cenozoic | Cretaceous Tertiary)
Raton Formation; in Raton Basin; unit contains conformable K/T boundary
Redonda Formation of Chinle Group (Phanerozoic | Mesozoic | Triassic)
Redonda Formation
Rock Point Formation of Chinle Group (Phanerozoic | Mesozoic | Triassic)
Rock Point Formation of Chinle Group; Upper Triassic. May locally include Lukachukai Member of Wingate Sandstone
Salado Formation (Phanerozoic | Paleozoic | Permian)
Salado Formation; evaporite sequence; Upper Permian
Sandia Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian)
Sandia Formation; predominately clastic unit (commonly arkosic) with minor black shales, and limestone in lower part; locally includes Osha Canyon Formation in Nacimiento Mountains
Santa Rosa Formation of Chinle Group (Phanerozoic | Mesozoic | Triassic)
Santa Rosa Formation; Carnian; includes Moenkopi Formation (Middle Triassic) at base in most areas
Tres Hermanos Formation (Phanerozoic | Mesozoic | Cretaceous)
Tres Hermanos Formation; formerly designated as Lower Gallup Sandstone in the Zuni Basin; Turonian
Vermejo Formation and Trinidad Sandstone (Phanerozoic | Mesozoic | Cretaceous)
Vermejo Formation and Trinidad Sandstone; Maastrichtian
Yesa Formation (Phanerozoic | Paleozoic | Permian)
Yeso Formation; sandstones, siltstones, anhydrite, gypsum, halite, and dolomite; Leonardian
Yeso, Glorieta, and San Andres Formations, undivided (Phanerozoic | Paleozoic | Permian)
Yeso, Glorieta and San Andres Formations, undivided
Zuni and Entrada Sandstones (Phanerozoic | Mesozoic | Jurassic)
Zuni and Entrada Sandstones, undivided
Zuni Sandstone (Phanerozoic | Mesozoic | Jurassic)
Zuni Sandstone; consists of undivided equivalents of the Summerville Formation and Bluff Sandstone; restricted to Zuni Basin area
Nevada
Antler Sequence of Silberling and Roberts (1962) (Pennsylvanian to Late Permian )
ANTLER SEQUENCE OF SILBERLING AND ROBERTS (1962) (Middle Pennsylvanian to Early or Late Permian) (Guadalupian)-Conglomerate, sandy to conglomeratic limestone, limestone, sandstone, and calcareous shale. Thin detrital and carbonate sequence within main part of Antler orogenic belt. Includes units such as Sunflower Formation of Bushnell (1967) in Elko County, Battle Formation, Antler Peak Limestone, and Edna Mountain Formation in Lander and western Eureka Counties, and Wildcat Peak Formation in northern Nye County
Argillaceous limestone, chert, and shale (Devonian)
ARGILLACEOUS LIMESTONE, CHERT, AND SHALE-Elko and Eureka Counties
Ash-flow tuffs and tuffaceous sedimentary rocks (Middle Miocene to Late Miocene)
ASH-FLOW TUFFS AND TUFFACEOUS SEDIMENTARY ROCKS
Aztec Sandstone (Early Jurassic)
AZTEC SANDSTONE (Triassic? And Jurassic)-Friable fine- to medium-grained sandstone with conspicuous large-scale cross strata; considered eolian. Age based on correlation with Navajo Sandstone
Banbury Formation (Middle Miocene to Late Miocene)
BANBURY FORMATION-Basalt, gravel, and tuffaceous sediments locally. Northeast Humboldt County and northwest Elko County
Cherty limestone and sparse dolomite, shale, and sandstone (Permian)
CHERTY LIMESTONE AND SPARSE DOLOMITE, SHALE, AND SANDSTONE (Lower and Upper Permian)-Includes units such as Park City Group and equivalent rocks in northern Nevada and Toroweap Formation and Kaibab Limestone in southern Nevada
Chinle Formation and associated rocks (Late Triassic)
CHINLE FORMATION AND ASSOCIATED ROCKS (Upper Triassic)-Continental deposits of variegated bentonitic claystone, siltstone, and clayey sandstone; ledge-forming sandstone; and red siltstone
Conglomerate, limestone, meta-andesite, phyllite, and shale (Devonian to Mississippian)
CONGLOMERATE, LIMESTONE, META-ANDESITE, PHYLLITE, AND SHALE-Includes Grossman, Banner, Nelson, and Mountain City Formation. Northern Elko County
Conglomerate, sandstone, shale, and dolomite of Diablo Formation below and shale, sandstone, and conglomerate of Candelaria Formation above (Early Permian to Early Triassic)
CONGLOMERATE, SANDSTONE, SHALE, AND DOLOMITE OF DIABLO FORMATION BELOW AND SHALE, SANDSTONE, AND CONGLOMERATE OF CANDELARIA FORMATION ABOVE (Lower or Upper Permian to Lower Triassic)-Mineral, Esmeralda, and northwestern Nye Counties
Continental deposits of siltstone, shale, conglomerate, and limestone (Cretaceous)
CONTINENTAL DEPOSITS OF SILTSTONE, SHALE, CONGLOMERATE, AND LIMESTONE-Includes units such as King Lear Formation in Humboldt County, Newark Canyon Formation in Eureka County, Willow Tank Formation and baseline Sandstone in Clark County
Continental sedimentary rocks (Late Cretaceous to Early Miocene)
CONTINENTAL SEDIMENTARY ROCKS-Clark County
Continental sedimentary rocks (Late Cretaceous to Eocene)
CONTINENTAL SEDIMENTARY ROCKS-Includes units such as Pansy Lee Conglomerate in Humboldt County, part of Cretaceous(?) and Tertiary rocks of Kleinhampl and Ziony (1967) in northern Nye County, and part of "older clastic rocks" of Tschanz and Pampeyan (1970) in Lincoln County
Dolomite, limestone, and minor amounts of sandstone and quartzite (Devonian)
DOLOMITE, LIMESTONE, AND MINOR AMOUNTS OF SANDSTONE AND QUARTZITE-Includes units such as Sevy and Simonson Dolomites, Guilmette and Nevada Formations, and Devils Gate Limestone.
Dunlap Formation (Early Jurassic to Middle Jurassic)
DUNLAP FORMATION (Lower and Middle Jurassic)-Conglomerate, sandstone, greenstone, felsite, and tuff. Locally contemporaneous with folding and thrusting. Mineral County and adjacent parts of Esmeralda and Nye Counties
Harmony Formation (Late Cambrian)
HARMONY FORMATION (Upper Cambrian)-Feldspathic and arkosic sandstone and minor amounts of shale, limestone, and chert.
Havallah sequence of Silberling and Roberts (1962) (Mississippian to Permian)
HAVALLAH SEQUENCE OF SILBERLING AND ROBERTS (1962)-Chert, argillite, shale, greenstone, and minor amounts of siltstone, sandstone, conglomerate, and limestone. Includes Schoonover Formation of Fagan (1962) and Reservation Hill Formation in Elko County, Farrel Canyon Formation in southwestern Humboldt County, Havallah and Pumpernickel Formations in Pershing, Lander, and parts of Humboldt Counties, and rocks originally considered a part of the Pablo and Excelsior Formations in northern Nye, northern Esmeralda, and southern Mineral Counties. Assignment of some rocks to the Havallah sequence in the East Range, Pershing County, is highly uncertain. Includes rocks ranging in age from Late Mississippian to Early Permian
Horse Spring Formation (Late Oligocene to Middle Miocene)
HORSE SPRING FORMATION-Tuffaceous sedimentary rocks, southern Nevada
Limestone and dolomite, locally thick sequences of shale and siltstone (Late Cambrian to Middle Cambrian)
LIMESTONE AND DOLOMITE, LOCALLY THICK SEQUENCES OF SHALE AND SILTSTONE-Includes units such as Pioche Shale, Eldorado Dolomite, Geddes Limestone, Secret Canyon Shale, Hamburg Dolomite, Dunderberg Shale, and Windfall Formation of northern Nevada and Carrara, Bonanza King, and Nopah Formations of southern Nevada.
Limestone and minor amounts of dolomite and shale (Mississippian)
LIMESTONE AND MINOR AMOUNTS OF DOLOMITE AND SHALE-Includes units such as Rogers Spring and Monte Cristo Limestones
Limestone and sparse dolomite, siltstone, and sandstone (Mississippian to Early Permian)
LIMESTONE AND SPARSE DOLOMITE, SILTSTONE, AND SANDSTONE-Includes units such as undivided Riepe Spring Limestone of Steele (1960) and Ely Limestone or their equivalent in Elko, White Pine, and northern Lincoln Counties and most of the Bird Spring Formation and Callville Limestone in Clark and southern Lincoln Counties. Includes some stratigraphically higher Permian rocks in Leppy Peak, easternmost Elko County.
Limestone, dolomite, and shale (Mississippian to Permian)
LIMESTONE, DOLOMITE, AND SHALE (Upper Paleozoic)-Includes Van Duzer Limestone of Decker (1962)
Limestone, minor amounts of dolomite, shale, and sandstone; locally thick conglomerate units (Triassic)
LIMESTONE, MINOR AMOUNTS OF DOLOMITE, SHALE, AND SANDSTONE; LOCALLY THICK CONGLOMERATE UNITS (Lower, Middle, and Upper Triassic)-Includes Tobin, Dixie Valley, Favret, Augusta Mountain, and Cane Spring Formations and Star Peak Group in central Nevada and Grantsville and Luning Formations in west-central Nevada
Massive limestone (Mississippian)
MASSIVE LIMESTONE-In the San Antonio Mountains, western Nye County
Moenkopi Formation, Thaynes Formation, and related rocks (Early Triassic to Middle Triassic)
MOENKOPI FORMATION, THAYNES FORMATION, AND RELATED ROCKS (Lower Triassic)-Marine deposits of siltstone, limestone, and sparse conglomerate
Phyllitc siltstone, quartzite, and lesser amounts of limestone and dolomite (Late Proterozoic to Early Cambrian)
PHYLLITIC SILTSTONE, QUARTZITE, AND LESSER AMOUNTS OF LIMESTONE AND DOLOMITE-Includes Reed Dolomite; Deep Spring, Campito, Poleta, Harkless, and Saline Valley Formations; and Mule Spring Limestone
Phyllite, shale, and limestone (Middle Cambrian to Ordovician)
PHYLLITE, SHALE, AND LIMESTONE-Locally includes chert and quartzite. Includes Tennessee Mountain Formation of Bushnell (1967) in western Elko County, Broad Canyon sequence of Means (1962) in Lander County, and rocks originally mapped as Palmetto Formation in Toiyabe and Toquima Ranges, northern Nye County
Quartzite and minor amounts of conglomerate, phyllitic siltstone, limestone, and dolomite (Late Proterozoic to Early Cambrian)
QUARTZITE AND MINOR AMOUNTS OF CONGLOMERATE, PHYLLITIC SILTSTONE, LIMESTONE, AND DOLOMITE-Includes Prospect Mountain Quartzite, Osgood Mountain Quartzite, and Gold Hill Formation in northern Nevada, and Stirling Quartzite, Wood Canyon Formation, and Zabriskie Quartzite in southern Nevada.
Sandstone and quartzite (Cambrian)
SANDSTONE AND QUARTZITE-Includes Tapeats Sandstone and related rocks. Rests on Precambrian metamorphic rocks.
Sandy and silty limestone, conglomerate, and siltstone (Pennsylvanian to Late Permian)
SANDY AND SILTY LIMESTONE, CONGLOMERATE, AND SILTSTONE (Upper Pennsylvanian to Upper Permian)-Includes units such as Strathearn Formation of Dott (1955) and Buckskin Mountain, Beacon Flat, and Carlin Canyon Formations of Dott (1955)
Scott Canyon Formation (Early Cambrian to Middle Cambrian)
SCOTT CANYON FORMATION (Lower or Middle Cambrian)-Chert, shale, greenstone, and sparse limestone and quartzite. Southeast Humboldt County and northwest Lander County.
Sedimentary rocks (Late Cretaceous to Oligocene)
SEDIMENTARY ROCKS-Includes Sheep Pass Formation (Eocene) and related units and unnamed tuffaceous sedimentary rocks
Shale and chert (Silurian)
SHALE AND CHERT-Includes Fourmile Canyon Formation in Eureka County and Noh Formation of Riva (1970) and unnamed rocks in Elko County.
Shale, chert, and minor amounts of quartzite, greenstone, and limestone (Ordovician)
SHALE, CHERT, AND MINOR AMOUNTS OF QUARTZITE, GREENSTONE, AND LIMESTONE-Includes units such as Vinini Formation of north-central Nevada, Palmetto Formation in southern and central parts of Esmeralda County, and Comus Formation in Humboldt County. Locally includes rocks of Silurian and Devonian age.
Shale, mudstone, siltstone, sandstone, and carbonate rock; sparse volcanic rock (Late Triassic to Early Jurassic)
SHALE, MUDSTONE, SILTSTONE, SANDSTONE, AND CARBONATE ROCK; SPARSE VOLCANIC ROCK (Upper Triassic and Lower Jurassic)-Includes Auld Lang Syne Group, Nightingale sequence of Bonham (1969), and Gabbs and Sunrise Formations
Shale, sandstone, volcanogenic clastic rocks, andesite, rhyolite, and locally thick carbonate units (Late Triassic to Early Cretaceous)
SHALE, SANDSTONE, VOLCANOGENIC CLASTIC ROCKS, ANDESITE, RHYOLITE, AND LOCALLY THICK CARBONATE UNITS-Undivided sequence locally containing recognizable equivalents of the Luning and Dunlap Formations
Shale, siliceous siltstone, chert, and minor amounts of limestone (Devonian)
SHALE, SILICEOUS SILTSTONE, CHERT, AND MINOR AMOUNTS OF LIMESTONE-Includes Cockalorum Wash Formation of northern Nye County and Woodruff Formation and unnamed rocks in Elko County
Shale, siltstone, sandstone, chert-pebble conglomerate, and limestone (Devonian to Mississippian)
SHALE, SILTSTONE, SANDSTONE, CHERT-PEBBLE CONGLOMERATE, AND LIMESTONE-Includes units such as Pilot Shale, Joana Limestone, Chainman Shale, and Diamond Peak Formation in northern and eastern Nevada and Narrow Canyon Limestone, Mercury Limestone, and Eleana Formation in southern Nevada
Siliceous and volcanic rocks (Mississippian)
SILICEOUS AND VOLCANIC ROCKS-In Humboldt County, consists of altered pillow lavas, coarse volcanic breccias, clastic limestone, and minor amounts of sandstone, shale, siliceous shale, and chert of the Goughs Canyon Formation (Lower and Upper Mississippian). In the East Range, Pershing County, consists of quartzite, conglomerate, slate, limestone, chert, and greenstone of the Inskip Formation (Mississippian?).
Siltstone, sandstone, limestone, and dolomite (commonly silty or sandy) and gypsum (Early Permian)
SILTSTONE, SANDSTONE, LIMESTONE, AND DOLOMITE (COMMONLY SILTY OR SANDY), AND GYPSUM (Lower Permian)-Includes units such as Rib Hill Sandstone and Pequop Formation of Steele (1959) in Elko County, Rib Hill Sandstone and Arcturus Formation in White Pine County, Queantoweap Sandstone of NcNair (1951), Hermit Shale, and Coconino Sandstone in Clark and southern Lincoln Counties.
Slaven Chert (Devonian)
SLAVEN CHERT-Chert and sparse limy sandstone, siltstone, and limestone. Lander County
Tuffaceous sedimentary rocks (Late Eocene to Late Miocene)
TUFFACEOUS SEDIMENTARY ROCKS-Locally includes minor amounts of tuff
Tuffaceous sedimentary rocks (Early Oligocene to Early Miocene)
TUFFACEOUS SEDIMENTARY ROCKS-Locally includes minor amounts of tuff
Volcanic flows and flow breccias, chiefly of andesitic composition, tuffs, sparse sandstone and graywacke (Permian to Jurassic)
VOLCANIC FLOWS AND FLOW BRECCIAS, CHIEFLY OF ANDESITIC COMPOSITION, TUFFS, SPARSE SANDSTONE AND GRAYWACKE-Includes Happy Creek Volcanic Series and related rocks in Humboldt County and similar rocks in Washoe and Pershing Counties; includes andesite breccias and volcanogenic sedimentary rocks in Mineral County
Volcanogenic sedimentary rocks, tuff, andesite and felsitic flows, and carbonate rocks (Permian to Jurassic (?))
VOLCANOGENIC SEDIMENTARY ROCKS, TUFF, ANDESITIC AND FELSITIC FLOWS, AND CARBONATE ROCKS-Age uncertain. Mineral, Esmeralda, and Northwest Nye Counties
Wyman Formation (Late Proterozoic)
WYMAN FORMATION-Phyllite and phyllitic siltstone and minor amounts of limestone, dolomite, and sandstone
New York
Beekmantown Group (in part) (Cambrian)
Beekmantown Group (in part) - In Champlain Valley: Whitehall Formation-dolostone, limestone (with Cryptozoon reefs); Ticonderoga Formation-dolostone (locally cherty), sandstone. In Vermont: Clarendon Springs Dolostone; Danby Formation-sandstone, quartzite, dolostone.
Bloomsburg Formation (Upper Silurian)
Bloomsburg Formation - shale, sandstone; Guymard Quartzite; Otisville Shale; Shawangunk Conglomerate-sandstone, conglomerate.
Brunswick Formation (Upper Triassic)
Brunswick Formation - sandstone, siltstone and mudstone.
Brunswick Formation (Upper Triassic)
Brunswick Formation - mudstone, sandstone and arkose.
Brunswick Formation (Upper Triassic)
Brunswick Formation - sandstone and conglomerate.
Brunswick Formation, undivided (Upper Triassic)
Brunswick Formation, undivided - includes the units: TRbg: sandstone and conglomerate; TRbs: sandstone, siltstone, mudstone; TRba: mudstone, sandstone, and arkose.
Clinton Group (Lower Silurian)
Clinton Group - Herkimer Sandstone; Kirkland Hematite; Willowvale Shale; Westmoreland Hematite; Sauquoit Formation-sandstone, shale; Oneida Conglomerate.
Clinton Group (Silurian)
Clinton Group - Herkimer Sandstone including Joslin Hill and Jordanville Members; Kirkland Hematite; Willowvale Shale; Westmoreland Hematite; Sauquoit Formation-sandstone, shale; Otsquago Sandstone; Oneida Conglomerate.
Conneaut Group, undivided (Upper Devonian)
Conneaut Group, undivided - Germania Formation-shale, sandstone; Whitesville Formation-shale, sandstone; Hinsdale Sandstone; Wellsville Formation-shale, sandstone; Cuba Sandstone.
Conneaut Group, undivided (Upper Devonian)
Conneaut Group, undivided - In west: Ellicott and Dexterville Formations-shale, siltstone. In east: Germania Formation-shale, sandstone; Whitesville Formation-shale, sandstone; Hinsdale Sandstone; Wellsville Formation-shale, sandstone; Cuba Sandstone.
Connoquenessing and Sharon Formations (Lower Pennsylvanian)
Connoquenessing and Sharon Formations - sandstone, shale; Sharon Formation-shale, sandstone, conglomerate; Olean Conglomerate 50-100 ft. (15-30 m).
Cuyahoga and Knapp Formations (Lower Mississippian)
Cuyahoga and Knapp Formations - Cuyahoga Formation-shale, sandstone; Corry Sandstone; Knapp Formation-shale, conglomerate 60-100 ft. (20-30 m).
"Enfield" and Kattel Formations (Upper Devonian)
"Enfield" and Kattel Formations - shale, siltstone, sandstone.
Honesdale Formation (Upper Devonian)
Honesdale Formation - sandstone, shale.
Honesdale Formation (Upper Devonian)
Honesdale Formation - sandstone, shale.
Irondequoit Limestone thru Kodak Sandstone (Lower Silurian)
Irondequoit Limestone thru Kodak Sandstone - includes: Irondequoit Limestone, Rockway Dolostone, Hickory Corners Limestone, Neahga Shale, and Kodak Sandstone.
Irondequoit Limestone thru Kodak Sandstone (Lower Silurian)
Irondequoit Limestone thru Kodak Sandstone - includes: Irondequoit Limestone, Williamson Shale; Wolcott Furnace Hematite; Wolcott Limestone; Sodus Shale; Bear Creek Shale; Wallington Limestone; Furnaceville Hematite; Maplewood Shale; Kodak Sandstone.
Lower Walton Formation (Upper Devonian)
Lower Walton Formation - shale, sandstone, conglomerate.
Lower Walton Formation (Upper Devonian)
Lower Walton Formation - shale, sandstone, conglomerate.
Ludlowville Formation (Middle Devonian)
Ludlowville Formation - In west: Deep Run Shale, Tichenor Limestone, Wanakah and Ledyard Shales, Centerfield Limestone Members. In east: King Ferry Shale and other members, Stone Mill Sandstone Member.
Ludlowville Formation (Middle Devonian)
Ludlowville Formation - Deep Run Shale, Tichenor Limestone, Wanakah and Ledyard Shales, Centerfield Limestone Members.
Machias Formation (Upper Devonian)
Machias Formation - shale, siltstone; Rushford Sandstone; Caneadea, Canisteo, and Hume Shales; Canaseraga Sandstone; South Wales and Dunkirk Shales; In Pennsylvania: Towanda Formation-shale, sandstone.
Machias Formation (Upper Devonian)
Machias Formation - shale, siltstone; Rushford Sandstone; Caneadea, Canisteo, and Hume Shales; Canaseraga Sandstone; South Wales and Dunkirk Shales.
Marcellus Formation (Middle Devonian)
Marcellus Formation - Pecksport, Solsville, Otsego, and Chittenango shale and sandstone Members, Cherry Valley Limestone, and Union Springs Shale Members.
Medina Group (Lower Silurian)
Medina Group - Grimsby Formation-sandstone, shale.
Medina Group (Lower Silurian)
Medina Group - consists of: Thorold Sandstone; Grimsby Formation-sandstone, shale; Power Glen and Cabot Head Shales; Whirlpool Sandstone.
Moscow Formation (Middle Devonian)
Moscow Formation - in west: Cooperstown and Portland Point shale and sandstone Members; In east: "Manorkill" and Portland Point shale and sandstone Members.
Moscow Formation (Middle Devonian)
Moscow Formation - shale, sandstone.
New Milford Formation (Upper Devonian)
New Milford Formation - "New Milford" Formation: sandstone, shale.
Normanskill Shale (Middle Ordovician)
Normanskill Shale - minor mudstone, sandstone.
Nunda Formation (Upper Devonian)
Nunda Formation - sandstone, shale.
Nunda Formation (Upper Devonian)
Nunda Formation - sandstone, shale.
Nunda Formation, West Hill Formation (Upper Devonian)
Nunda Formation, West Hill Formation - Nunda: sandstone, shale; West Hill: shale, siltstone; Corning Shale.
Oneonta Formation (Middle - Upper Devonian)
Oneonta Formation - shale, sandstone.
Oneonta Formation (Middle - Upper Devonian)
Oneonta Formation - shale, sandstone, conglomerate.
Oneonta Formation (Middle - Upper Devonian)
Oneonta Formation - shale, sandstone.
Onondaga and Bois Blanc Limestones (Middle Devonian)
Onondaga and Bois Blanc Limestones - In New York: Onondaga Limestone-Seneca, Morehouse (cherty), and Clarence Limestone Members, Edgecliff cherty Limestone Member, local coral bioherms; Bois Blanc Limestone-sandy, thin, discontinous. In Ontario: Dundee Limestone; Lucas Formation-dolostone, limestone (Anderdon); Amherstburg Formation-limestone, dolostone, sandstone (Sylvania); Bois Blanc Formation-dolostone, limestone, sandstone (Springvale).
Oriskany Formation (Lower Devonian)
Oriskany Formation - sandstone, arenaceous limestone.
Oriskany Sandstone (Lower Devonian)
Oriskany Sandstone.
Oriskany Sandstone (Lower Devonian)
Oriskany Sandstone.
Oswayo and Venango Formations (Upper Devonian)
Oswayo and Venango Formations - shale, siltstone, sandstone; replaced eastwardly by Cattaraugus Formation-shale, sandstone, conglomerate.
Oswego Sandstone (Upper Ordovician)
Oswego Sandstone
Oswego Sandstone (Upper Ordovician)
Oswego Sandstone
Oswego Sandstone (Upper Ordovician)
Oswego Sandstone
Panther Mountain Formation (Middle Devonian)
Panther Mountain Formation - shale, siltstone, sandstone.
Panther Mountain Formation (Middle Devonian)
Panther Mountain Formation - shale, siltstone, sandstone.
Plattekill and Ashokan Formations (Middle Devonian)
Plattekill Formation - shale, sandstone; Ashokan Formation-shale, sandstone.
Plattekill and Ashokan Formations (Middle Devonian)
Plattekill Formation - shale, sandstone; Ashokan Formation-shale, sandstone.
Potsdam Sandstone (Cambrian)
Potsdam Sandstone
Potsdam Sandstone (Cambrian)
Potsdam Sandstone (Covey Hill in Quebec)
Quassaic Quartzite (Upper Ordovician)
Quassaic Quartzite - quartzite, sandstone, conglomerate.
Rondout Formation (Upper Silurian)
Rondout Formation - dolostone, limestone; Binnewater Sandstone; High Falls Shale; Warwarsing Limestone; Decker Limestone; Bossardville Limestone; Poxono Island Formation-shale, dolostone.
Schenectady Formation (Upper Ordovician)
Schenectady Formation - graywacke, sandstone, siltstone, shale.
Skaneateles Formation (Middle Devonian)
Skaneateles Formation - In west: Levanna Shale and Stafford Limestone Members; In east: Butternut, Pompey, and Delphi Station Shale Members, Mottville Sandstone Member.
Slide Mountain Formation (Upper Devonian)
Slide Mountain Formation - sandstone, shale, conglomerate.
Slide Mountain Formation (Upper Devonian)
Slide Mountain Formation - sandstone, shale, conglomerate.
Slide Mountain Formation (Upper Devonian)
Slide Mountain Formation - sandstone, shale, conglomerate.
Theresa Formation (Cambrian - Lower Ordovician)
Theresa Formation - dolostone, sandstone (Chateauguay in Quebec).
Theresa (Galway) Formation (Cambrian)
Theresa (Galway) Formation - dolostone, sandstone, shale.
Unadilla, Laurens, New Lisbon, and Gilboa Formations (Middle Devonian)
Unadilla, Laurens, New Lisbon, and Gilboa Formations - shale, siltstone, sandstone.
Undifferentiated Hamilton Group (Middle Devonian)
Undifferentiated Hamilton Group - shale, siltstone. In eastern Orange County: Skunnemunk Formation-sandstone, conglomerate; Bellvale Formation-shale, sandstone; Cornwall Shale.
Undifferentiated Lower Devonian and Silurian rocks (Lower Devonian - Silurian)
Undifferentiated Lower Devonian and Silurian rocks - in northern Ulster County: Port Ewen thru Manlius Limestones; Rondout Dolostone; Binnewater Sandstone; High Falls Shale. In Orange County: Kanhouse Sandstone; Woodbury Creek Formation-shale, sandstone; Esopus Shale; Connelly Conglomerate; Central Valley Sandstone; New Scotland Limestone thru Rondout Dolostone; Decker Limestone; Poxono Island Formation-shale, dolostone; Longwood Shale; Green Pond Conglomerate.
Undifferentiated Lower Hamilton Group (Middle Devonian)
Undifferentiated Lower Hamilton Group - Panther Mountain, Mount Marion, Stony Hollow, and Union Springs shales and sandstones.
Undifferentiated Lower Hamilton Group (Middle Devonian)
Undifferentiated Lower Hamilton Group - shale and sandstone.
Undifferentiated Medina Group and Queenston Formation (Upper Ordovician - Lower Silurian)
Undifferentiated Medina Group and Queenston Formation - Grimsby Formation-sandstones, shale; and Queenston Formation-siltstone, shale.
Undifferentiated Medina Group and Queenston Formation (Upper Ordovician - Lower Silurian)
Undifferentiated Medina Group and Queenston Formation - Grimsby Formation-sandstones, shale; and Queenston Formation-shale, siltstone.
Upper Walton Formation (Upper Devonian)
Upper Walton Formation - shale, sandstone, conglomerate.
Upper Walton Formation (Upper Devonian)
Upper Walton Formation - shale, sandstone, conglomerate.
Wiscoy Formation (Upper Devonian)
Wiscoy Formation - sandstone, shale; Hanover and Pipe Creek Shales.
Wiscoy Formation (Upper Devonian)
Wiscoy Formation - sandstone, shale; Hanover and Pipe Creek Shales.
Ohio
Allegheny and Pottsville Groups, Undivided (Pennsylvanian)
Allegheny and Pottsville Groups, Undivided - Shale, siltstone, and underclay: Shale, black, gray, and olive; clayey to silty; locally contains marine fossils; calcareous in part. Siltstone, gray, greenish and olive; clayey to sandy; thin bedded to medium bedded; locally contain marine fossils. Underclay, gray and olive; generally 3 feet or less in thickness; clayey to silty; commonly rooted and underlying coal beds; nonbedded; locally varies from flint to plastic clay. Sandstone, light to medium gray weathers to shades of yellow-brown; mostly very fine to medium grained, locally quartzose and conglomeratic in lower one-third of unit; thin to massive to cross bedded; locally calcareous; Limestone, flint and coal. Limestone, black to light gray; micritic to medium grained; locally grades into flint; thin to medium bedded to discoidal concretions containing marine fossils; locally nonmarine, micritic limestones occur beneath coal beds in upper one third of unit. Coal, mostly banded bituminous, locally cannel; thin to locally as much as 12 feet thick; generally in discrete beds but locally contain shale partings and split into multiple beds. Lateral and vertical lithic variability and gradation common. Unit as much as 700 feet thick.
Berea Sandstone and Bedford Shale, Undivided (Devonian)
Berea Sandstone and Bedford Shale, Undivided - Sandstone and shale; upper portion sandstone; brown, weathers light brown to reddish brown; thin to thick bedded, planar to lenticular bedding; minor shale interbeds; 5 to 75 feet thick, locally 100 to 125 feet thickness in Lorain, Cuyahoga, and Medina Counties; lower portion shale; gray to brown, locally reddish brown; thin to medium bedded, planar to lenticular bedding; interbedded siltstone and sandstone, ripple marks in siltstone beds; 80 to 180 feet thick, locally thin to absent where Berea Sandstone is thick.
Black Hand Sandstone Member of Cuyahoga Formation (Mississippian)
Black Hand Sandstone Member of Cuyahoga Formation - Sandstone and conglomerate; yellow-gray to white, weathers shades yellow, brown, red, and gray; very fine grained to pebbles, mostly medium to coarse grained with lenses and layers of pebbles; massive to crossbedded to laminated; grades laterally into shale and siltstone; quartzose.
Conemaugh Group (Pennsylvanian)
Conemaugh Group - Shale, siltstone, and mudstone: Shale, black, gray, green and red; clayey to silty; locally contains marine fossils in lower half of unit; calcareous in part. Siltstone, gray, green and red, locally variegated; clayed to sandy; thin bedded to nonbedded. Mudstone, black, gray, green, red, and yellow, variegated in part; clayey to silty; locally calcareous; commonly nonbedded. Sandstone, green-gray weathers to shades of yellow-brown; mostly very fine to medium grained, locally conglomeratic; thin to massive to cross bedded; locally calcareous. Limestone and coal; thin and discontinuous. Limestone, black, gray and green; micritic to coarse grained; thin bedded to concretionary with marine fossils common in lower half of interval; thin to medium bedded, nonmarine limestone common in upper half of unit. Coal, thin, bituminous, impure; very locally thick enough for economic development. Lateral and vertical lithic variability and gradation common. Unit as much as 500 feet thick.
Detroit River Group (Devonian)
Detroit River Group - Dolomite; brown to gray; medium to thick bedded; laminated; nodules or interbeds of anhydrite and/or gypsum; basal part becomes sandy dolomite or fine-grained sandstone; as much as 170 feet thick.
Dunkard Group (Permian and/or Pennsylvanian)
Dunkard Group - Mudstone, shale, and siltstone (60-70 percent); shades of red, yellow, olive, and/or brown in southern areas of Ohio to gray, green and black in northern areas; clayey to sandy; nonbedded to thin bedded; locally calcareous. Sandstone (25-35 percent); blue-gray weathers to shades of yellow-brown; fine grained to locally conglomeratic; thin to massive to cross bedded. Limestone and coal (5 percent): Limestone, gray, micritic, clayey to silty, thin to medium bedded in northern areas of Ohio, nodular bedded to argillaceous in southern areas. Coal, black, banded, thin, discontinuous, impure; poorly developed in southern areas of Ohio. Limestones and coals best developed in lower 90 to 200 feet. Lateral and vertical lithic variability and gradation common. Unit greater than 600 feet thick in southeast Ohio.
Maxville Limestone; Rushville, Logan, and Cuyhoga Formations, Undivided (Mississippian)
Maxville Limestone; Rushville, Logan, and Cuyhoga Formations, Undivided - Shale, siltstone, and sandstone, interbedded; various shades of gray, yellow to brown weather similar color; sandstone, silty to granular, local stringers of quartz pebbles. Shale, clayey to silty, locally fossiliferous. Medium to dark gray, thin to thick bedded limestone locally preserved at top of interval where unit crops out in southern half of state. Lithologies percentages vary in different areas where unit crops out; laterial and vertical gradation common at regional scale.
Mississippian and Devonian Undifferentiated (Devonian and/or Mississippian)
Mississippian and Devonian Undifferentiated - Sandstone and shale, interbedded. Occurs only in Serpent Mound Impact Structure.
Monongahela Group (Pennsylvanian)
Monongahela Group - Shale, siltstone, and mudstone; black, red, gray and green to variegated red and yellow in the southeastern areas of Ohio; clayey to sandy; nonbedded to thin bedded; locally calcareous. Sandstone, greenish-gray weathers to shades of yellow-brown, silty to locally conglomeratic; thin to massive to cross bedded; locally calcareous. Limestone, gray, micritic, clayey to silty, thin to medium bedded; generally more common in middle and lower portions of unit. Coal, banded, bituminous, thin to as much as 8 feet thick in central and northern areas, thinner to absent in southeastern Ohio. Lateral and vertical lithic variability and gradation common. Unit as much as 350 feet thick.
Sunbury Shale, Berea Sandstone, and Bedford Shale, Undivided (Devonian and/or Mississippian)
Sunbury Shale, Berea Sandstone, and Bedford Shale, Undivided - Shale and sandstone; upper 10 to 50 feet shale; black to brown, weathers light brown; carbonaceous; thin, planar bedding. Underlain by 10 to 50 feet sandstone; brown, weathers light brown to reddish brown; thin to thick bedded, planar to lenticular bedding; minor shale interbeds. Basal 80 to 100 feet shale and interbedded sandstone; gray to brown, weathers light gray to light brown; thin to medium bedded, planar to lenticular bedding; thick. Interval thickness ranges from 100 to 200 feet.
Oklahoma
Ada Group or Ada Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late)
ENID- "Ada Group"- Mainly shale with many limestone layers that are thinner and pinch out southward, where fine-grained sandstones are thicker and more numerous. Near Kansas border, group includes (descending): "Auburn shale" (50 feet thick) at top, underlain by "Wakarusa Limestone," IPaw (2 feet thick), unnamed shale (40 feet thick), "Rulo Limestone" (3 feet thick), unnamed shale (18 feet thick), "Happy Hollow Limestone" (2 feet thick), unnamed shale and sandstone (60 feet thick), "Bird Creek Limestone," IPab (2 feet thick; called "Church Limestone" in Kansas), "Severy-Aarde Shale" (70 feet thick), "Turkey Run Limestone," IPat (2 feet thick; called "Coal Creek Limestone" in Kansas), unnamed shale (30 feet thick), "Pearsonia Limestone" (3 feet thick), unnamed shale (15 feet thick), "Little Hominy Limestone" (22 feet thick), "Deer Creek Limestone (15 feet thick), unnamed shale (10 feet thick), "Plummer Limestone" (2 feet thick), unnamed shale (35 feet thick), and "Beil Limestone Member" (10 feet thick) of "Lecompton Limestone" at base. Total thickness, about 400 feet (120 m). OKLAHOMA CITY- "Ada Group"- Mostly orange-brown fine-grained sandstone and red-brown to gray shale; grades southward into chert conglomerates. Includes the following thin limestone beds and shale units north of North Canadian River (descending): "Auburn Shale" (80 feet thick), "Wakarusa Limestone," IPaw (1 to 6 feet thick), unnamed shale (95 feet thick), "Bird Creek Limestone," IPab (1 to 9 feet thick), "Severy-Aarde Shale" (45 feet thick), "Turkey Run Limestone," IPat (1 foot thick), unnamed shale (45 feet thick), and "Lecompton Limestone" (1.5 to 10 feet thick), at base. Total thickness of group ranges from 100 feet in south to 280 feet in north. ARDMORE-SHERMAN- "Ada Formation"- (= Collings Ranch Conglomerate) Shale, red-brown to gray, bituminous sandstone, and limestone conglomerate; thickness, 100 to 1,400 feet (subsurface), decreasing southward.
Antlers Sand or Antlers Sandstone (Phanerozoic | Mesozoic | Cretaceous-Early )
ARDMORE-SHERMAN- "Antlers Sand" Sand, white to yellow, medium-grained, weakly indurated, with varicolored clays. Contains arkosic conglomerates near Arbuckle Mountains and "Baum Limestone" near Mannsville anticline. Thickness, 200 to 700 feet. McALESTER TEXARKANA- "Antlers Sandstone" Sandstone and sand, white to reddish-yellow to orange-brown to gray, fine- to coarse-grained, quartzose, crossbedded, moderately to weakly indurated, interbedded with varicolored clays and conglomerates; contains fossil wood and dinosaurs; rests unconformably upon Ouachita rocks but conformably upon DeQueen Limestone; thickness, 0 to 320 feet, thickening southeastward to 900 feet in subsurface.
Atoka, Bloyd and Hale Formations Undifferentiated (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early Pennsylvanian-Middle)
FORT SMITH- IPu Undifferentiated. Atoka, Bloyd, and Hale Formations. IPat "Atoka Formation," shale and sandstone, IPbh "Bloyd Formation," shale and limestone; and "Hale Formation," limestone and sandstone.
Atoka Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
TULSA- IPat "Atoka Formation," shale, siltstone, sandstone, and thin limestone. FORT SMITH- IPat "Atoka Formation," shale and sandstone. ARDMORE-SHERMAN- Shale, dark-gray, and sandstone, buff to white, fine- to coarse-grained, with some chert conglomerates; thickness, 800 to 3,000 feet. McALESTER TEXARKANA- Shale, gray to tan, illitic, chloritic, with many sandstones, fine- to coarse-grained, quartzose, micaceous, well- to poorly sorted; "Fanshawe" and "Red Oak Sandstones" in middle and "Spiro Sandstone" at base; thickness, 3,000 to 10,000 feet, increasing southeastward in subsurface, south of growth faults.
Barnsdall Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
ENID- Formation is mainly fine- to medium-grained sandstone, overlain by shale. At top is a thick shale, with "Okesa Sandstone Member" in middle and "Birch Creek Limestone" (called "South Bend Limestone") at base. Birch Creek extends southward from Kansas border to Township 23 N., where limestone grades into overlying Okesa Sandstone. South of Township 23 N., Okesa grades downward into underlying "Torpedo Sandstone" and underlying Wann Formation. Total thickness ranges from 45 to 200 feet (14 to 60 m). OKLAHOMA CITY- Mostly fine-grained sandstone overlain by shale; may grade northward into "Wann Formation". Thickness ranges from about 80 to 200 feet.
Bison Formation or Bison Shale (Phanerozoic | Paleozoic | Permian )
WOODWARD- "Bison Formation"- Mostly orange-brown to greenish-gray fine-grained sandstone. Thickness ranges up to 120 feet. ENID- "Bison Formation"-Mainly red-brown shale and greenish-gray and orange-brown calcitic siltstone with minor sandstone in Garfield County. Thickness, about 120 feet (35 m). (Hennessey Group) CLINTON- "Bison Formation," Pbi, is exposed as orange-brown and greenish-gray, fine-grained sandstone and siltstone. The Bison is gradational southward into reddish-brown shale; it thins southward and is about 120 feet thick. OKLAHOMA CITY- "Bison Formation"-Mostly red-brown shale; grades northward into many thin greenish-gray calcitic siltstones and some orange-brown fine-grained sandstones and siltstones. "Reeding Sandstone Bed" at base. Thickness ranges from 95 feet in south to 120 feet in north. (Hennessey Group). ARDMORE-SHERMAN- "Bison Shale"-Shale, gray to red-brown, calcareous, blocky; thickness, 50 to 90 feet, decreasing southward. (Hennessey Group)
Blakely Sandstone (Phanerozoic | Paleozoic | Ordovician-Early)
McALESTER TEXARKANA- Sandstone, gray to brown, fine- to coarse-grained, quartzose, micaceous; grades into beds above, with sharp quartzitic contact below; thickness, 10 to 15 feet, with maximum thickness in Arkansas 400 feet. Occurs in POTATO HILLS, BROKEN BOW UPLIFT or ADJACENT SMALLER UPLIFTS IN SOUTHEASTERN PART OF OUACHITA MOUNTAINS
Blaylock Sandstone (Phanerozoic | Paleozoic | Silurian)
McALESTER TEXARKANA- Sandstone, greenish-gray, fine grained, well indurated, alternating with dark-gray to brown phyllites and shales in lower 100 feet; occurs only in Broken Bow Uplift and adjacent area; thickness, 670 to 804 feet, with maximum thickness in Arkansas 1,500 feet. Occurs in POTATO HILLS, BROKEN BOW UPLIFT or ADJACENT SMALLER UPLIFTS IN SOUTHEASTERN PART OF OUACHITA MOUNTAINS
Bloyd and Hale Formations (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early)
TULSA- "Bloyd Formation," limestone and shale. "Hale Formation," limestone and sandstone. FORT SMITH- IPbh "Bloyd Formation," shale and limestone; and "Hale Formation," limestone and sandstone.
Bluejacket Sandstone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
ARDMORE-SHERMAN- "Bluejacket Sandstone," IPbj, sandstone, at base, of Boggy FM, 8 to 12 feet thick, with 2-foot "Secor coal" 50 feet above top of Bluejacket. McALESTER TEXARKANA- Sandstone, tan, fine- to coarse-grained, micaceous, quartzose, moderately to well-indurated; erodes into a mappable escarpment; thickness, 12 to 266 feet, increasing eastward.
Boggy Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
TULSA- Shale, sandstone, and coal. FORT SMITH- Shale, sandstone, and coal; includes Bluejacket Sandstone Member at base. ARDMORE-SHERMAN- Shale and sandstone, blue-gray to brown, fine- to coarse- grained, with some thin limestone lenses and a coal bed 2.5 feet thick about 400 feet above base. Thickness, 1,250 to 2,800 feet. "Bluejacket Sandstone," IPbj, at base, 8 to 12 feet thick, with 2-foot "Secor coal" 50 feet above top of Bluejacket. (Lower Franks Conglomerate) McALESTER TEXARKANA- Shale, brown, to blue-gray, illitic, chloritic, with many sandstones, fine- to coarse-grained, micaceous, quartzose, moderately to well-indurated, with "Secor coal" about 50 feet above base; thickness, 2,140 to 4,000 feet, increasing eastward.
Bokchito Formation (Phanerozoic | Mesozoic | Cretaceous-Early )
ARDMORE-SHERMAN- Clay, illitic, kaolinitic, with some tan limestones and sandstones. Subdivided into "Pawpaw Clay" at top, 40 to 60 feet thick; "Quarry Limestone," 13 feet thick; "Weno Clay," 100 to 135 feet thick; and basal "Denton Clay," 50 to 70 feet thick.
Bromide + Tulip Creek and McLish Formations (Phanerozoic | Paleozoic | Ordovician-Middle)
ARDMORE-SHERMAN- Limestone, buff; shale, grayish-green; and sandstone, brown to white, fine- to medium-grained: approximate sequence of rocks in each formation, from top to bottom. Thickness, 750 to 1,400 feet, thinning eastward. (Simpson Group) Occurs in the ARBUCKLE MTNS
Calvin Sandstone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
OKLAHOMA CITY- Medium-grained, thin-bedded to massive sandstone nd silty shale. Thickness ranges from 230 to about 440 feet. FORT SMITH- Shale and sandstone ARDMORE-SHERMAN- Sandstone, brown, medium-grained, with some gray shale; thickness, 40 to 320 feet, thinner southward.
Cedar Hill Sandstone (Phanerozoic | Paleozoic | Permian )
WOODWARD- Orange-brown to greenish-gray fine-grained sandstone and siltstone, with some red-brown shale. Thickness ranges up to 180 feet, with more sandstone to the north and more shale to the south. ENID- Mainly orange-brown, fine-grained quartzose sandstone. Thickness about 180 feet (55 m). (El Reno Group) CLINTON- "Cedar Hill Sandstone," Pch, greenish-gray sandstone and reddish-brown shales; thickness, about 180 feet; gradational southward into Duncan Sandstone. OKLAHOMA CITY- Lenticular beds of orange-brown fine-grained sandstone and red-brown shale; lower part grades southward into "Duncan Sandstone". "Piedmont Sandstone Bed" at base. Thickness, 180 feet (only lower 80 feet exposed in mapped area). (El Reno Group)
Chanute Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
ENID- Mainly fine-grained micaceous sandstone and coarse-grained, crossbedded sandstone separated by shale. Locally Chanute contains thin coal seams. Thickness ranges from about 10 to 150 feet (3 to 45 m). TULSA- Thin- to thick-bedded, fine- to coarse-grained sandstone and shale. OKLAHOMA CITY- Mainly fine- to medium-grained sandstone 3 to 20 feet thick, overlain by shale 20 to 80 feet thick. Total thickness ranges from about 25 to 90 feet.
Chattanooga + Fernvale + Fite + Tyner + Burgen + Cotter Formations (Phanerozoic | Paleozoic | Ordovician-Early Ordovician-Middle(?) Ordovician-Late(?) Silurian(?) Devonian(?) Carboniferous Mississippian-Early(?) Mississippian-Middle(?) Mississippian-Late)
TULSA- "Chattanooga Formation," shale and minor sandstone. "Fernvale Formation," limestone. "Fite Formation," limestone "Tyner Formation," shale and dolomite "Burgen Sandstone," sandstone and minor dolomite and shale. "Cotter Formation," dolomite and minor sandstone.
Chickasha Formation (Phanerozoic | Paleozoic | Permian )
WOODWARD- The "Chickasha Formation" member of Flower Pot Shale (Pc) is a deltaic tongue of red-brown to greenish-gray to orange-brown cross-bedded mudstone conglomerate, siltstone, shale, and fine-grained sandstone, about 30 feet thick, in the middle of the Flowerpot Shale, pinching out northward. CLINTON- "Chickasha Formation," Pc, reddish-brown to maroon mudstone conglomerate with some shale, silstone, and fine- to coarse-grained sandstone; thickness, about 600 feet; gradational northward and westward into the Flowerpot Shale and the Blaine Formation and westward into Dog Creek Shale. OKLAHOMA CITY-Variegated mudstone conglomerate and red-brown to orange- brown silty shale and siltstone, with minor amounts of orange-brown fine-grained sandstone; upper part grades northward into "Dog Creek Shale", "Blaine Formation", "Flowerpot Shale", and upper part of "Cedar Hills Sandstone"; lower part grades into "Duncan Sandstone". Thickness, about 100 feet near Chickasha and 300 feet near Okarche. (El Reno Group) ARDMORE-SHERMAN- Mudstone conglomerate, siltstone, and sandstone, red-brown; thickness, 100 to 200 feet, decreasing southeastward. (El Reno Group)
Cloud Chief Formation (Phanerozoic | Paleozoic | Permian )
WOODWARD- Red-brown and greenish-gray shale and siltstone with some orange-brown fine-grained sandstone and siltstone. At base are two or more thin, pink to maroon to greenish-gray dolomite beds and (or) gypsum beds ("Moccasin Creek Bed") eroding into a mappable escarpment. About 25 feet above the base is a white to light-gray dolomite ("Day Creek Bed") not mapped. Thickness ranges up to 160 feet, with top eroded in many places. CLINTON- Reddish-brown to orange-brown shale, interbedded with siltstone and sandstone in the middle part and some dolomite and much gypsum in lower part; thickness about 400 feet, thinning northward to about 175 feet. The "Moccasin Creek Gypsum Member" is at the base. LAWTON- Represented in this area by the "Moccasin Creek Gypsum Member," which is about 30 feet (9 m) thick.
Coffeyville and Checkerboard Formations or Checkerboard Limestone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
ENID- "Coffeyville Formation" is mainly shale interbedded with fine-to medium-grained sandstone. Locally formation contains thin coal seams. Thickness ranges from 175 to 470 feet (50 to 140 m). Underlying "Checkerboard Limestone" is crystalline limestone 2 to 15 feet (1 to 5 m) thick. TULSA- "Coffeyville Formation," shale and thin-bedded sandstone. "Checkerboard Formation," limestone and some shale. OKLAHOMA CITY- "Coffeyville Formation," mainly shale interbedded with fine- to medium-grained sandstone locally containing chert and limestone conglomerate and thin coal seams; thickness, 150 to 470 feet. Underlying "Checkerboard Limestone," crystalline limestone 2.5 to 5 feet thick.
Coffeyville or Francis Formation (restricted) (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
ARDMORE-SHERMAN- Shale, dark-blue, 20 to 70 feet thick, with "DeNay Limestone," yellow, massive, 2 to 6 feet thick at base, and 20 feet or more of buff fine- to coarse-grained sandstone and chert conglomerate at top. (Upper Franks Conglomerate)
Cool Creek and McKenzie Hill Formations (Phanerozoic | Paleozoic | Ordovician-Early)
LAWTON- "Cool Creek Formation" and "McKenzie Hill Formation," Ocm, limestone and conglomerate with abundant quartz sand and cherty zones; thickness, approximately 2,000 feet (600 m). (Upper part of Arbuckle Group) ARDMORE-SHERMAN- Limestone, gray to tan, fine-grained, cherty, gradational eastward into dolomites and sandstones; thickness, 1,500 to 2,300 feet, decreasing eastward. (Arbuckle Group) Occurs in the ARBUCKLE MTNS
Crystal Mountain Sandstone (Phanerozoic | Paleozoic | Ordovician-Early)
McALESTER TEXARKANA- Sandstone, pink to light-gray to dark-gray, fine- to coarse-grained, quartzose, with well-rounded, frosted grains, quartzitic, fractured in many places, with many quartz and orthoclase veins; 14-foot chert- and limestone-pebble conglomerate occurs at base; thickness, 500 feet or more, with maximum thickness in Arkansas 850 feet (called Lower Cool Creek in Arbuckle Mountains and Roubidoux Sandstone in Ozarks). Occurs in POTATO HILLS, BROKEN BOW UPLIFT or ADJACENT SMALLER UPLIFTS IN SOUTHEASTERN PART OF OUACHITA MOUNTAINS
Dakota Group (Phanerozoic | Mesozoic | Cretaceous-Early )
CLINTON- Outliers of the "Kiowa Formation," Kk, dark-gray shale with some thin beds of fossiliferous tan limestone, range in thickness from a few feet to about 20 feet. Associated in some places is a 5- to 10-foot, gray to brown, coarse-grained sandstone and conglomerate assigned to the overlying "Dakota Group," Kd, (lower sandstone part).
Dakota Sandstone (Phanerozoic | Mesozoic | Cretaceous-Early )
CIMARRON- Buff to light-brown, fine- to medium-grained, thin bedded to massive sandstone with interbedded shales.
Deese Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
ARDMORE-SHERMAN- Member of Glenn Fm, mainly massive sandstone, conglomerate and shale. Base of "Confederate Limestone" down to top of "Otterville Limestone;" thickness, 9,700 feet. Occurs in the ARDMORE BASIN
Dewey Formation or Dewey Limestone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
ENID- "Dewey Limestone"- Mainly medium-crystalline limestone and shale. Thickness ranges from 0 to 60 feet (0 to 18 m). TULSA- "Dewey Formation"- Limestone and some shale. (Mapped with the Chanute formation south of Bartlesville) OKLAHOMA CITY- "Dewey Limestone"- Mainly sandy limestone or calcareous sandstone containing limestone lenses 1.5 to 20 feet thick, overlain by shale 5 to 50 feet thick. Total thickness ranges from 20 to 60 feet.
Dexter Member of Woodbine Formation (Phanerozoic | Mesozoic | Cretaceous-Late )
ARDMORE-SHERMAN- sandstone, shale, and lignite, moderately to weakly indurated, about 100 feet thick.
Dockum Group (Phanerozoic | Mesozoic | Triassic-Late )
CIMARRON- Upper shale unit: Varicolored siltstone or claystone, conglomerate, fine-grained sandstone, and limestone. Lower sandstone unit: Varicolored, fine- to coarse-grained sandstone with some clay and interbedded shale.
Doe Creek Lentil of Marlow Formation (Phanerozoic | Paleozoic | Permian )
WOODWARD- In Woods and Woodward Counties, the "Doe Creek Lentil" (Pmd) is a coarse-grained calcareous sandstone with algal clumps and invertebrate fossils, ranging up to 70 feet thick from the base of the Marlow to the Relay Creek Bed, cropping out in a narrow band of high hills striking northeast.
Dog Creek Shale (Phanerozoic | Paleozoic | Permian )
WOODWARD- Red-brown shale and silty shale, with gypsum, dolomite, and orange-brown sandstone. In upper part are many thin,dense light-gray dolomite beds, the basal one of which is named "Southard Bed" (unmapped); in lower part is much satin-spar gypsum with a greenish-gray dolomite at top termed "Watonga Bed" (unmapped). Thickness ranges from 30 feet or less at Kansas border to 100 feet in southern part of area. CLINTON- "Dog Creek Shale," Pdc, reddish-brown shale with thin beds of siltstone and dolomite; thickness, about 220 feet; gradational eastward into the Chickasha Formation. OKLAHOMA CITY- Mostly red-brown silty shale and some fine-grained sandstone. Contains one or two layers of thin dolomite (or gypsum) in lower part; basal part grades southward into "Chickasha Formation". Thickness averages about 200 feet. (El Reno Group) LAWTON- "Dog Creek Shale," Pdc, reddish-brown silty shale, 85 to 190 feet (26 to 58 m) thick. (El Reno Group) ARDMORE-SHERMAN- Shale, red-brown, blocky, silty, weakly indurated, gradational southward into "Chickasha Formation;" thickness, 0 to about 130 feet. (El Reno Group)
Dornick Hills Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
ARDMORE-SHERMAN- Series of tan shales with limestones, limestone conglomerate and sandstone. Top of "Otterville Limestone" down to base of "Lake Ardmore Sandstone;" thickness 1,800 feet. Occurs in the ARDMORE BASIN
Duncan Sandstone (Phanerozoic | Paleozoic | Permian )
CLINTON- "Duncan Sandstone," Pd, light-gray and reddish-brown, cross-bedded, fine-grained sandstone and mudstone conglomerate with some interbedded yellowish-gray and reddish-brown shales; thickness, about 200 feet; gradational into the Cedar Hills Sandstone northward and into the Flowerpot Shale northward and westward. OKLAHOMA CITY- Mainly red-brown to orange-brown fine-grained sandstone, with some mudstone conglomerate and shale; grades northward into "Cedar Hills Sandstone" and "Chickasha Formation". Thickness, 450 feet near Chickasha, 300 feet near Oklahoma City, and 100 feet or more near Okarche. (El Reno Group) ARDMORE-SHERMAN- Sandstone, white to buff, fine- to coarse-grained, moderately indurated, with interbedded mudstone conglomerates and siltstones; thickness, 100 to 400 feet, decreasing southeastward. (El Reno Group)
Eagle Ford Formation (Phanerozoic | Mesozoic | Cretaceous-Late )
ARDMORE-SHERMAN- Shale, dark-gray, plastic; thickness, about 50 feet; top eroded.
Elk City Sandstone (Phanerozoic | Paleozoic | Permian )
CLINTON- Reddish-brown, fine-grained sandstone with minor amounts of silt and clay, weakly cemented by iron oxide, calcium carbonate, and gypsum; maximum thickness 185 feet, top eroded.
El Reno Group (Phanerozoic | Paleozoic | Permian )
CLINTON- Primarily evaporites and reddish-brown shale, with deltaic clastics to the southeast. Where separate formations have not been distinguished, the "El Reno Group" is mapped as Per; El Reno Group. Includes: "Dog Creek Shale," Pdc, reddish-brown shale with thin beds of siltstone and dolomite; thickness, about 220 feet; gradational eastward into the Chickasha Formation. "Blaine Formation," Pb, 3 to 4 gypsum and dolomite beds, about 100 to 200 feet thick, separated by reddish-brown shale. Gradational southward and eastward into Chickasha Formation. "Flowerpot Shale," Pf, reddish-brown shale containing several salt and gypsum beds in the upper part. Thickness, about 300 to 450 feet; gradational southward and eastward into Chickasha Formation and Duncan Sandstone. "Cedar Hill Sandstone," Pch, greenish-gray sandstone and reddish-brown shales; thickness, about 180 feet; gradational southward into Duncan Sandstone. "Chickasha Formation," Pc, reddish-brown to maroon mudstone conglomerate with some shale, silstone, and fine- to coarse-grained sandstone; thickness, about 600 feet; gradational northward and westward into the Flowerpot Shale and the Blaine Formation and westward into Dog Creek Shale. "Duncan Sandstone," Pd, light-gray and reddish-brown, cross-bedded, fine-grained sandstone and mudstone conglomerate with some interbedded yellowish-gray and reddish-brown shales; thickness, about 200 feet; gradational into the Cedar Hills Sandstone northward and into the Flowerpot Shale northward and westward. LAWTON- Primarily evaporites and reddish-brown shale, with deltaic clastics to the east. In the eastern part of the quadrangle, separate formations have not been distinguished, and the "El Reno Group" is mapped as Per; in the western part of the quadrangle, the group has been mapped as four separate formations. "El Reno Group undifferentiated," Per, in northeastern part of the quadrangle, includes "Chickasha Formation" sandstone, shale, and siltstone, 400 to 580 feet (120 to 180 m) thick-and underlying "Duncan Sandstone" (equivalent to San Angelo Sandstone)-sandstone with some shale, 100 to 250 feet (30 to 76 m) thick.
Exeter (Entrada) Sandstone (Phanerozoic | Mesozoic | Jurassic-Late )
CIMARRON- Massive, white to buff, fine- to medium-grained sandstone 0 to 50 +/- feet thick.
Flowerpot Shale (Phanerozoic | Paleozoic | Permian )
WOODWARD- Red-brown silty shale with some thin gypsum and dolomite beds in upper 50 feet and fine-grained sandstones in upper part to north. The middle and upper parts contain 50 feet or more of rock salt in the immediate subsurface, giving origin to the Ferguson Salt Plain in Blaine County and the Big and Little Salt Plains in Woods and Harper Counties on the Cimarron River. Thickness ranges from 180 feet in north part to 430 feet in south part. The "Chickasha Formation" (Pc) is a deltaic tongue of red-brown to greenish-gray to orange-brown cross-bedded mudstone conglomerate, siltstone, shale, and fine-grained sandstone, about 30 feet thick, in the middle of the Flowerpot Shale, pinching out northward. CLINTON- "Flowerpot Shale," Pf, reddish-brown shale containing several salt and gypsum beds in the upper part. Thickness, about 300 to 450 feet; gradational southward and eastward into Chickasha Formation and Duncan Sandstone. OKLAHOMA CITY- Mostly red-brown silty clay shale with stringers of gypsum (satin spar and selenite); grades southward into "Chickasha Formation". Thickness, 20 to 40 feet. (El Reno Group) LAWTON- "Flowerpot Shale," Pf, reddish-brown and greenish-gray shale, interbedded with greenish-gray siltstone; thickness, about 175 to 195 feet (53 to 59 m).
Garber Sandstone (Phanerozoic | Paleozoic | Permian )
ENID- Mostly orange-brown, fine- to medium-grained quartzose sandstone and conglomerate, grading northward into shale and calcitic siltstone. Thickness, about 600 feet (180 m). (Sumner Group) OKLAHOMA CITY- Mostly orange-brown to red-brown fine-grained sandstone, irregularly bedded with red-brown shale and some chert and mudstone conglomerate. Thickness ranges from 150 feet in south to 400 feet or more in north. (Sumner Group) LAWTON- "Garber Sandstone," Pg, reddish-brown, fine-grained sandstone and mudstone conglomerate, 160 to 210 feet (49 to 64 m) thick, containing a basal sandstone, the "Asphaltum Sandstone Bed," about 10 to 60 feet (3 to 18 m) thick.(Sumner Group) ARDMORE-SHERMAN- Sandstone, red-brown, fine- to coarse-grained; thickness, about 110 to 150 feet, including Fairmont Shale west of Elmore City, Garvin County
Goddard Shale (Phanerozoic | Paleozoic | Carboniferous Mississippian-Late)
ARDMORE-SHERMAN- 1. Mainly shale, gray, limonitic; thickness, 3,600 feet in Ardmore Basin, 240-450 feet on Lawrence uplift. In places includes "Rod Club" and "Overbrook Sandstones" and "Union Valley Formation-Wapanucka" shale. Occurs in the ARBUCKLE MTNS 2. Shale, gray, limonitic; estimated thickness, 500 feet, but may be 2,500 Occurs in the OUACHITA MNTS McALESTER TEXARKANA- Shale, gray to black, with some sandstones and ironstone concretions; thickness, 500 feet or more. Occurs in the OUACHITA MTNS NORTH OF TI VALLEY FAULT
Hartshorne Sandstone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
ARDMORE-SHERMAN- Sandstone, gray to white, medium- to coarse-grained with interbedded middle gray shale and "Lower Hartshorne coal;" thickness, 10 to 300 feet. McALESTER TEXARKANA- Sandstone, tan to gray to white, fine- to coarse-grained, micaceous, quartzose, moderately to well-indurated, with some interbedded gray shale; "Lower Hartshorne coal" in middle and "Upper Hartshorne coal" at top; thickness, 100 to 350 feet, increasing eastward.
Hennessey Group (Phanerozoic | Paleozoic | Permian )
CLINTON- Reddish-brown shale with some thin, greenish-gray siltstone and orange-brown sandstone and siltstone beds; thickness, about 500 feet. The "Hennessey Group" is not subdivided in the southern part of the Clinton quadrangle; in the northeastern corner of the quadrangle, the upper part of the "Bison Formation," Pbi, is exposed as orange-brown and greenish-gray, fine-grained sandstone and siltstone. The Bison is gradational southward into reddish-brown shale; it thins southward and is about 120 feet thick. LAWTON- "Hennessey Group," Phy, reddish-brown to gray shale with some tan sandstones, 130 to 200 feet (40 to 60 m) thick (locally unconformable on Cambrian igneous rocks).
Hilltop Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
OKLAHOMA CITY- Mainly shale, grading upward into massive siltstone and fine- grained sandstone; grades northward into "Barnsdall Formation", "Chanute Formation", and "Dewey Limestone". Thickness ranges from 0 to 200 feet. ARDMORE-SHERMAN- Shale, blue-gray to red-brown, with buff siltstones and fine-grained sandstones at top; thickness, about 70 feet.
Holdenville and Lenapah Formations (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
TULSA- "Holdenville Formation," shale and minor sandstone and limestone. "Lenapah Formation", limestone and shale. (Map unit only in Tulsa County)
Holdenville Formation or Holdenville Shale (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
OKLAHOMA CITY- "Holdenville Shale"- Mainly clay shale with some interbedded fine-grained calcareous sandstone locally containing beds of crystalline limestone. Thickness ranges from 100 to 280 feet. FORT SMITH- "Holdenville Shale"- Shale, thin sandstone and minor limestones. ARDMORE-SHERMAN- "Holdenville Formation"- Shale, blue-gray, with light-brown sandstones and chert conglomerates and 2 prominent limestones--the upper, or "Sasakwa Limestone," white, fine-grained, 1 to 15 feet thick, 35 feet below the top, and the lower, or "Homer Limestone," dark-brown, sandy, 2 to 10 feet thick, 40 to 70 feet below the Sasakwa. Thickness, 210 to 260 feet. (Upper Franks Conglomerate)
Hoxbar Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
ARDMORE-SHERMAN- Upper most member of Glenn Fm, consisting of brown limestone, white sandstone, and shale. "Zuckerman Sandstone" (top eroded) down to base of "Confederate Limestone;" thickness, 2,800 feet. Occurs in the ARDMORE BASIN
Jackfork Group or Jackfork Sandstone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early)
ARDMORE-SHERMAN- "Jackfork Sandstone"- Sandstone, gray, white, and tan, coarse-grained, cherty, with gray shale and some boulders up to 7 feet in diameter; thickness 1,150 to 5,000 feet Occurs in the OUACHITA MNTS McALESTER TEXARKANA- "Jackfork Group"- Sandstone, tan to gray, fine- to coarse-grained, quartzose, with some mica, poorly to well-indurated, quartzitic has some gray shale and several maroon shales; black, white-speckled "Chickasaw Creek Chert" is at base; thickness, 1,500 to 6,000 feet or more. Occurs in the OUACHITA MTNS SOUTH OF TI VALLEY FAULT
Kindblade Formation (Phanerozoic | Paleozoic | Ordovician-Early)
ARDMORE-SHERMAN- Limestone, gray to tan, fine-grained, gradational eastward into tan fine- to coarse-grained dolomite; some tan to gray sandstone and shale; thickness, 1,875 to 3,000 feet, decreasing eastward. (Arbuckle Group) Individual Fm description not found. Occurs in the ARBUCKLE MTNS
Kingman Formation or Kingman Siltstone (Phanerozoic | Paleozoic | Permian )
WOODWARD- "Kingman Formation"- Orange-brown to greenish-gray fine-grained sandstone and siltstone, with some red-brown shale. Thickness is about 70 feet. ENID- "Kingman Siltstone"- Mainly red-brown with several thin layers of greenish-gray and orange-brown calcitic siltstone. Thickness, about 70 feet (20 m). (Hennessey Group) OKLAHOMA CITY- "Kingman Siltstone"- Orange-brown to greenish- gray, even bedded siltstones with some fine-grain sandstone and red-brown shale; grades southward into "Purcell Sandstone". Thickness, 30 feet. (Hennessey Group)
Kiowa Formation (Phanerozoic | Mesozoic | Cretaceous-Early )
WOODWARD- Gray and yellow shale and limestone, with many "Texigryphaea" shells locally. At base is 5 to 10 feet of greenish-gray sandstone in places. Thickness ranges up to 140 feet with top eroded. CLINTON- Outliers of the "Kiowa Formation," Kk, dark-gray shale with some thin beds of fossiliferous tan limestone, range in thickness from a few feet to about 20 feet. Associated in some places is a 5- to 10-foot, gray to brown, coarse-grained sandstone and conglomerate assigned to the overlying "Dakota Group," Kd, (lower sandstone part).
Labette Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
TULSA- Shale and thin sandstone and limestone.
Lewisville Member of Woodbine Formation (Phanerozoic | Mesozoic | Cretaceous-Late )
ARDMORE-SHERMAN- mostly shale and weakly indurated sandstone, about 75 feet thick.
Limestone Gap (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early)
McALESTER TEXARKANA- Shale and sandstone, gray to tan, illitic, chloritic, micaceous, quartzose, fine- to coarse-grained, moderately to well-indurated, with some ironstone concretions and many bottom marks; thickness, approximately 1,000 feet, pinching out in subsurface near Ti Valley Fault. Fault. Occurs in the OUACHITA MTNS NORTH OF TI VALLEY FAULT.
Lower part of Arbuckle Group and Timbered Hills Group (Phanerozoic | Paleozoic | Cambrian-Furongian)
LAWTON- Limestone, dolomite, siltstone, sandstone, conglomerate, and shale, with glauconitic and hematitic zones; thickness, 1,200 to 2,000 feet (370 to 600 m), faulted in isolated areas. Lower part of "Arbuckle Group" includes "Signal Mountain Formation, Royer Dolomite," and "Fort Sill Limestone; Timbered Hills Group" includes "Honey Creek Formation" and "Reagan Sandstone."
Lynn Mountain Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early)
McALESTER TEXARKANA- Shale, gray to tan, with many fine- to coarse-grained, quartzose, micaceous sandstone with many bottom markings; top eroded; thickness, 3,000 to 7,000 feet or more; unconformable upon Goddard, Delaware Creek, Woodford, and older beds that are exposed north and west of Ti Valley Fault. Occurs in the OUACHITA MTNS
Marlow Formation (Phanerozoic | Paleozoic | Permian )
WOODWARD- Orange-brown fine-grained sandstone and siltstone, with some interbedded red-brown shale and silty shale in upper part and some thin gypsum beds at base, about 35 feet above base, and at top. The upper two gypsum and (or) dolomite beds are generally pink to maroon and less than 1 foot thick; they may erode into mappable escarpments about 20 feet apart, being named "Emanuel Bed" at top (mapped) and "Relay Creek Bed" 15 to 20 feet below the top (not mapped). In places the basal Marlow is a greenish-gray medium-grained sandstone. In Woods and Woodward Counties, the "Doe Creek Lentil" (Pmd) is a coarse-grained calcareous sandstone with algal clumps and invertebrate fossils, ranging up to 70 feet thick from the base of the Marlow to the Relay Creek Bed, cropping out in a narrow band of high hills striking northeast. Thickness is about 120 feet, with top eroded at many places. CLINTON- "Marlow Formation," Pm, orange-brown, fine-grained sandstone and siltstone, about 100 to 130 feet thick, thinning northward. This formation has 2 gypsum and (or) dolomite beds in upper 20 feet--the "Emanuel Bed" (at top) and the "Relay Creek Bed" (20 feet below top). Two thin, pale shales occur; the first is 1 foot below the top ("Gracemont") and the second is 55 feet above the base (unnamed). OKLAHOMA CITY- Mostly orange-brown fine-grained gypsiferous sandstone, with some red-brown shale. Contains 10 feet of calcitic sandstone lenses near middle and 2 thin dolomites (or gypsums) at top. Exposed thickness, about 50 feet (top 50 to 75 feet eroded). (Whitehorse Group) LAWTON- "Marlow Formation," Pm, very fine-grained sandstone with some silty shale; thickness, about 90 to 130 feet (27 to 40 m); contains 2 thin gypsum and (or) dolomite beds in upper 20 feet (6 m)-the "Emanuel Bed" (at top) and the "Relay Creek Bed" (20 feet below top). (Whitehorse Group) ARDMORE-SHERMAN- Sandstone, orange-brown, fine- to medium-grained, moderately indurated, with "Verden Sandstone Lentil," Pmv, 10 feet thick near middle, and "Relay Creek" and "Emanuel" dolomite and gypsum beds at top; thickness, 105 to 135 feet. (Whitehorse Group)
McAlester and Hartshorne Formations (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
TULSA- "McAlester and Hartshorne Formations", shale and some sandstone and coal. FORT SMITH- IPmh "McAlester" and "Hartshorne Formations" (undifferentiated), shale, sandstone, and coal.
McAlester Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
ARDMORE-SHERMAN- Shale, gray, with "Upper Hartshorne coal" 1 to 50 feet above base, 500 to 600 feet thick; overlain by dark-gray shale with many buff fine-grained sandstones, 595 to 1,030 feet thick; overlain by dark-gray shale, 300 to 925 feet thick, with "McAlester coal," 1 to 3 feet thick, a few feet above base. Total thickness ranges from 1,150 to 2,420 feet. (Lower Franks Conglomerate) McALESTER TEXARKANA- Shale, gray, illitic, chloritic, with many tan to gray sandstones, fine- to coarse-grained, micaceous, quartzose; "McAlester and Stigler coals" 600 to 800 feet or more below top; thickness, 2,000 to 2,830 feet, increasing eastward
Mesozoic rocks undifferentiated (Phanerozoic | Mesozoic | Triassic-Early Triassic-Middle(?) Triassic-Late(?) Jurassic(?) Cretaceous-Early(?) Cretaceous-Middle(?) Cretaceous-Late)
TEXAS- Red shale containing thin layers of yellow and gray clay and indistinctly bedded fine-grained buff, red, white, and gray sandstone. May include beds of Cretaceous, Jurassic, and Triassic ages. Their exposed thickness is less than 100 feet.
Missouri Mountain and Polk Creek Shales (Phanerozoic | Paleozoic | Ordovician-Late Silurian)
McALESTER TEXARKANA- Shale, greenish-gray to maroon to black; grades into phyllite in Broken Bow Uplift; contains some thin sandstones and gray conglomerates; a fossiliferous limestone occurs in Southeast quarter section 29, Township 4 South, Range 23 East; mapped as SmOp in Potato Hills, where it is included with Polk Creek Shale; thickness, 60 to 110 feet or less. Occurs in POTATO HILLS, BROKEN BOW UPLIFT or ADJACENT SMALLER UPLIFTS IN SOUTHEASTERN PART OF OUACHITA MOUNTAINS
Missouri Mountain Shale (Phanerozoic | Paleozoic | Silurian)
McALESTER TEXARKANA- Shale, greenish-gray to maroon to black; grades into phyllite in Broken Bow Uplift; contains some thin sandstones and gray conglomerates; a fossiliferous limestone occurs in Southeast quarter section 29, Township 4 South, Range 23 East; mapped as SmOp in Potato Hills, where it is included with Polk Creek Shale; thickness, 60 to 110 feet or less. Occurs in POTATO HILLS, BROKEN BOW UPLIFT or ADJACENT SMALLER UPLIFTS IN SOUTHEASTERN PART OF OUACHITA MOUNTAINS
Missouri Mountain Shale and Blaylock Sandstone (Phanerozoic | Paleozoic | Silurian)
ARDMORE-SHERMAN- "Missouri Mountain Shale," shale, black to gray-green to red; thickness, 100 feet; underlain by sandstone, several feet thick, correlated as "Blaylock." Occurs in the OUACHITA MNTS
Morrison Formation (Phanerozoic | Mesozoic | Jurassic-Late )
CIMARRON- Varicolored fine-grained sandstone, limestone, dolomite, shale, and conglomerate 0 to 470 +/- feet thick.
Morrowan-Atokan (?) rocks undifferentiated (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early Pennsylvanian-Middle)
ARDMORE-SHERMAN- Shale and sandstone, gray to brown, fine- to coarse-grained; thickness, 5,000 to 9,000 feet. Occurs in the OUACHITA MNTS
Morrowan rocks undifferentiated (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early)
ARDMORE-SHERMAN- Shale and sandstone, gray to brown, fine- to coarse- grained;estimated thickness, 3,000 feet Occurs in the OUACHITA MNTS.
Nellie Bly Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
TULSA- Shale and thin sandstone. ARDMORE-SHERMAN- Shale, siltstone, fine-grained sandstone, chert conglomerate, limestone, and limestone conglomerate, dark-gray to buff; thickness, 200 to 300 feet.
Nellie Bly Formation and Hogshooter Limestone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
ENID- "Nellie Bly Formation" consists mainly of shale with a few layers of fine- to medium-grained sandstone. Thickness ranges from 80 to 550 feet (25 to 170 m). Underlying "Hogshooter Limestone" is massive crinoidal limestone 1 to 50 feet (0.3 to 14 m) thick. OKLAHOMA CITY- "Nellie Bly Formation," mainly shale with many fine-grained sandstone beds and limestone beds locally in upper part; thickness, about 250 to about 550 feet. Underlying"Hogshooter Limestone," massive crinoidal limestone 1 to 15 feet thick.
Nowata Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
TULSA- Shale and minor sandstone and limestone.
Oil Creek and Joins Formation (Phanerozoic | Paleozoic | Ordovician-Middle)
ARDMORE-SHERMAN- Limestone, gray to tan, granular, with greenish-gray shale and brown fine- to medium-grained sandstone; thickness, 600 to 1,100 feet, decreasing eastward. (Simpson Group) Occurs in the ARBUCKLE MTNS
Oolagah Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
TULSA- Thin-bedded limestone and some shale in the southern part of the area. North of Oolagah, in western Rogers County, the map unit, IPol, includes the following formations: "Altamont Formation," limestone and minor shale; "Bandera Formation," shale and thin sandstone; "Pawnee Formation," limestone and minor shale.
Oscar Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late)
ENID- Mainly shale with many layers of limestones that pinch out southward, where fine-grained arkosic sandstones are thicker and more numerous. Near Kansas border, sequence is (descending): "Herington Limestone" (20 feet thick) at top, "Enterprise Shale" (45 feet thick), "Winfield Limestone, "IPowi (8 feet thick), "Gage Shale" (80 feet thick), "Towanda Limestone" (3 feet thick), "Holmesville Shale" (25 feet thick), "Fort Riley Limestone," IPofr (30 feet thick) and underlying Florence Flint, IPofr (8 feet thick), "Blue Springs Shale" (60 feet thick), "Kinney Limestone" (5 feet thick), "Wymore Shale" (22 feet thick), "Wreford Limestone," IPowr (25 feet thick), "Speiser Shale" (38 feet thick), "Funston Limestone (4 feet thick), "Blue Rapids Shale" (15 feet thick), "Crouse Limestone" (6 feet thick), "Easly Creek Shale" (12 feet thick), "Bader Limestone" (5 feet thick), "Stearns Shale" (10 feet thick), "Morrill Limestone" (2 feet thick), "Florena Shale" (6 feet thick), "Cottonwood Limestone," IPoc (3 feet thick), "Eskridge Shale" (6 feet thick), and "Neva Limestone" (25 feet thick) at base. Total thickness, about 400 feet. OKLAHOMA CITY- Red-brown to gray shale and orange-brown fine-grained, crossbedded sandstone; grades southward into arkosic sandstone and conglomerate. Includes "Herington Limestone" at top inPayne County, "Neva Limestone" (0.2 to 1.2 feet thick) at basein Lincoln County, and "Hart Limestone" (4 to 10 feet thick)at base in Pottawatomie County. In Payne County, includesthin stringers of "Winfield Limestone," IPowi (75 feet belowtop), "Fort Riley Limestone," IPofr (245 feet below top),"Wreford Limestone," IPowr (345 feet below top), and"Cottonwood Limestone," IPoc (525 feet below top). Thickness ranges from 300 feet in south to 600 feet in north. LAWTON- Shale, sandstone, and arkose, 300 to 500 feet (90 to 150 m) thick, base covered. ARDMORE-SHERMAN- Shale, red-brown to gray, with arkosic sandstones and limestone conglomerates near Arbuckle Mountains; "Hart Limestone" at base; thickness, 300 to 500 feet, decreasing southeastward. (Pontotoc Group)
Pawpaw Sandstone and McNutt Limestone (Phanerozoic | Mesozoic | Cretaceous-Early )
McALESTER TEXARKANA- "Pawpaw Sandstone," sandstone, yellowish- to reddish-gray, fine-grained, with gray to reddish-purple sandy clay; thickness, 35 feet. "McNutt Limestone" at base, limestone, grayish-brown, arenaceous, with "Rastellum quadriplicatum;" thickness, 2 to 3 feet.
Permian rocks undifferentiated (Phanerozoic | Paleozoic | Permian)
TEXAS- Red to dark reddish-brown shale, sandstone, and siltstone. Gypsum occurs in all rock units as a cementing agent, as tiny flakes, as thin irregular veinlets, and as discontinuous beds ranging from less than an inch to more than 30 feet thick. Maximum thickness exceeds 2,000 feet. BEAVER- Red shale, sandstone, and siltstone, are predominant rocks with lesser amounts of limestone, dolomite, gypsum, and salt. The undifferentiated Permian rocks include the Whitehorse Group, the Cloud Chief Formation, and the Quartermaster Formation; also included are local outcrops in the southwestern part of the county, which maybe Triassic in age, 3,800 feet thick
Pitkin + Fayetteville + Batesville + Hindsville + Moorefield Formations (Phanerozoic | Paleozoic | Carboniferous Mississippian-Late)
TULSA- "Pitkin Formation," limestone. "Fayetteville Formation," shale and thin limestone "Batesville Formation," fine-grained sandstone "Hindsville Formation," limestone and shale "Moorefield Formation," limestone, shale, and siltstone.
Pleistocene and Pliocene deposits, undifferentiated (Phanerozoic | Cenozoic | Tertiary Quaternary | Pliocene Pleistocene)
TEXAS- Interfingering beds, tongues, and lenses of sand, silt, clay, gravel, sandstone, caliche, limestone, conglomerate, and volcanic ash. Includes Ogallala and Laverne Formations of Pliocene age and younger deposits of Pleistocene age. Locally the units are tightly cemented by calcium carbonate; other places, they are very poorly consolidated and nearly free of cementing materials. Thickness ranges from 0 to about 800 feet.
Post Oak Conglomerate (Phanerozoic | Paleozoic | Permian )
LAWTON- "Post Oak Conglomerate," Ppo, limestone conglomerate near limestone outcrops; contains zeolite-opal ("Tepee Creek Formation") locally, near gabbro and anorthosite outcrops; arkosic gravel and cobbles near igneous outcrops. These rock types are interbedded with sand, silt, clay, and shale, as much as 500 feet (150 m) thick at surface but several thousand feet thick in subsurface, extending down section into Pennsylvanian rocks.
Purcell Sandstone (Phanerozoic | Paleozoic | Permian )
OKLAHOMA CITY- Red-brown to maroon fine- to coarse-grained sandstone, mudstone conglomerate, and red- brown shale. Thickness, 150 feet. (Hennessey Group) ARDMORE-SHERMAN- Sandstone, red-brown to maroon and greenish-gray, fine- to coarse-grained, with some shale and mudstone conglomerate; thickness, 90 to 150 feet, decreasing southward. (Hennessey Group).
Purgatoire Formation (Phanerozoic | Mesozoic | Cretaceous-Early )
CIMARRON- Kiowa Shale Member: Gray to black fossiliferous shale with sandstone in the upper part. Thickness ranges from 0 to 50 +/- feet. Cheyenne Sandstone Member: Massive, white to buff, fine- to medium-grained sandstone, containing some conglomerate in the lower part, from 0 to 120 +/- feet thick.
Red Branch Member of Woodbine Formation (Phanerozoic | Mesozoic | Cretaceous-Late )
ARDMORE-SHERMAN- indurated sandstone, shale, and lignite, about 75 feet thick, erodes to an escarpment; and basal Dexter Member.
Rush Springs Formation (Phanerozoic | Paleozoic | Permian )
WOODWARD- Orange-brown fine-grained sandstone, commonly crossbedded, with some interbedded red-brown shale, silty shale, and gypsum beds. In southern part of area, about 30 feet below top is a thin massive gypsum bed ("Weatherford Bed" or "One Horse Bed"), not mapped here. About 100 feet lower is another thin gypsum bed ("Old Crow Bed") not mapped here. Thickness is about 190 feet in southern part and 90 feet near Kansas border, with top eroded in many places. CLINTON- "Rush Springs Formation," Pr, orange-brown, cross-bedded, fine-grained sandstone with some dolomite and gypsum beds. Thickness, about 300 feet, thinning northward to about 186 feet. LAWTON- "Rush Springs Formation," Pr, very fine-grained, cross-bedded sandstone, 136 to 300 feet (41 to 90 m) thick. The "Weatherford Gypsum Bed," Prw, contains gypsum and dolomite and is as much as 60 feet (18 m) thick in the upper part of the Rush Springs. (Whitehorse Group) ARDMORE-SHERMAN- Sandstone, orange-brown, fine- to medium-grained, moderately indurated, with "Weatherford Gypsum Bed," Prw, 2 to 15 feet thick, near top. Thickness, about 280 feet, top eroded (Whitehorse Group)
Salt Plains Formation (Phanerozoic | Paleozoic | Permian )
WOODWARD- Orange-brown fine-grained sandstone and siltstone, with a greenish-gray sandstone in middle 30 feet ("Crisfield Sandstone Member") unmapped. Thickness ranges up to 160 feet. ENID- Mainly red-brown shale with several thin beds of orange-brown, fine-grained sandstone. Thickness about 160 feet (50 m). (Hennessey Group) OKLAHOMA CITY- Red-brown blocky shale orange-brown siltstone, grades southward into Pp "Purcell Sandstone" in Norman area. Thickness, 200 feet. (Hennessey Group)
San Angelo Sandstone (Phanerozoic | Paleozoic | Permian )
LAWTON- "San Angelo Sandstone," Psa, interstratified sandstone, mudstone conglomerate, and shale, as much as 80 feet (24 m) thick.
Savanna and McAlester Formations (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
FORT SMITH- IPsm "Savanna" and "McAlester Formations" (undifferentiated; T. 15 N., Rs. 18, 19 E.), shale and minor sandstones
Savanna Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
TULSA- "Savanna Formation," shale and thin sandstone, limestone, and coal. FORT SMITH- IPsa "Savanna Formation," shale, sandstone, and coal ARDMORE-SHERMAN- Sandstone and shale, gray to brown, fine- to coarse- grained, cherty, with several thin coal seams near middle; thickness, 1,120 to 1,600 feet (Lower Franks Conglomerate) McALESTER TEXARKANA- Shale, tan to brown, illitic, chloritic, and sandstone, fine-to coarse-grained, micaceous, quartzose, with several thin coal seams in middle, one of which is "Cavanal coal;" thickness, 1,470 to 2,000 feet, increasing eastward.
Savanna + McAlester + Hartshorne + Atoka Formations (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
TULSA- "Savanna, McAlester, Hartshorne, and Atoka Formations," shale, sandstone, siltstone, limestone, and coal.
Savanna + McAlester + Hartshorne Formations (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
TULSA- "Savanna, McAlester, and Hartshorne Formations," shale and some sandstone, limestone, and coal
Seminole Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
TULSA- Shale, sandstone, and thin coal beds. OKLAHOMA CITY- Chert conglomerate, shale, and fine-grained sandstone containing coal seams in upper part locally. Thickness ranges from 100 to 375 feet. FORT SMITH- Sandy shale, sandstone, and thin coal seams. ARDMORE-SHERMAN- Shale, gray-green, with buff fine-grained sandstones, chert conglomerates, and limy sandstones; thickness, about 120 feet. (Upper Franks Conglomerate)
Senora Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
TULSA- Shale with thin and lenticular sandstone, minor limestone, and coal. OKLAHOMA CITY- Mainly fine-grained micaceous sandstone and shale locally containing coal beds. Thickness ranges from about 500 to 950 feet. FORT SMITH- Shale, sandstone, and thin coal seams. ARDMORE-SHERMAN- Shale, gray, and light-brown medium-grained sandstone; thickness, 150 to 500 feet, decreasing southwestward. Subdivided into lower sandstone, 350 feet thick, and upper shale, 150 feet thick.
Stanley Group or Stanley Shale (Phanerozoic | Paleozoic | Carboniferous Mississippian)
ARDMORE-SHERMAN- "Stanley Shale"- Shale, dark-gray, siliceous,with some gray to buff fine-grained sandstones; thickness,10,000 feet Occurs in the OUACHITA MNTS McALESTER TEXARKANA- "Stanley Group"- Shale, olive-green to gray, illitic, chloritic, with many5- to 30-foot-thick beds of poorly sorted, micaceous, quartzose sandstones and some thin siliceous cherty beds and black shales; several tuff beds occur in basal 1,000 feet and are indicated by red line in Stanley exposures as designated on map; many asphaltite, lead, and quartz veins occur along fault zones; mostly Chesterian age; thickness, 7,500 to 14,000 feet or more. Occurs in the OUACHITA MTNS SOUTH OF TI VALLEY FAULT
Stuart Shale (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
OKLAHOMA CITY- Mostly laminated clay shale and minor amounts of silty sandstone. Thickness ranges from 80 to 180 feet. FORT SMITH- Shale and minor sandstone. ARDMORE-SHERMAN- Shale, blue to dark-gray, with some fine- to medium-grained brown sandstones; thickness, 80 to 300 feet, decreasing southwestward. McALESTER TEXARKANA- Shale, blue to dark-gray, with some fine- to medium-grained sandstones; top eroded; lower 20 feet exposed.
Tallant Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
ENID- Alternating layers of shale and fine- to medium-grained sandstone. Thickness ranges from 75 to 250 feet (23 to 75 m). OKLAHOMA CITY- Mostly fine- to medium-grained sandstone 10 to 60 feet thick overlain by shale 25 to 65 feet thick. Cut out by "Vamoosa Formation" in central part of area. Total thickness ranges from 0 to 100 feet.
Templeton Member of Woodbine Formation (Phanerozoic | Mesozoic | Cretaceous-Late )
ARDMORE-SHERMAN- indurated sandstone and shale, about 75 feet thick, erodes to an escarpment; (Woodbine Formation)
Thurman Sandstone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
OKLAHOMA CITY- Mainly medium-grained, silty sandstone with cherty conglomerate at base. Only a few feet exposed in quadrangle. FORT SMITH- Sandstone and shale. ARDMORE-SHERMAN- Sandstone, brown, fine- to coarse-grained, with some gray shale and basal 50-foot chert conglomerate; thickness, 80 to 250 feet, decreasing southwestward. McALESTER TEXARKANA- Sandstone, brown, fine- to coarse-grained, with some gray shale and a basal 50-foot chert conglomerate; grades northward into Boggy Formation; top eroded at many places; thickness, 200 feet.
Timbered Hills Group (Phanerozoic | Paleozoic | Cambrian-Furongian)
ARDMORE-SHERMAN- "Honey Creek Limestone," above, is gray, fine grained; grades eastward into dolomite; thickness 90 to 250 feet. "Reagan Sandstone," at base, is brown, coarse grained; thickness, 60 to 450 feet. Occurs in the ARBUCKLE MTNS
Tokio Formation (Phanerozoic | Mesozoic | Cretaceous-Late )
McALESTER TEXARKANA- Sand, light-gray, fine- to coarse-grained, quartzose, poorly sorted, crossbedded, and gray clay shale, with many cylindrical pipe structures, petrified wood and invertebrates; same as Bonham Marl and Austin Chalk of Texas; thickness ranges from 88 to 380 feet, increasing eastward; reaches thickness of 595 feet in subsurface southeastward.
Torpedo Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
TULSA- Thin-bedded to massive medium-grained sandstone and shale
Undifferentiated, Mississisippian, Devonian, Silurian, and Ordovician (Phanerozoic | Paleozoic | Ordovician-Early Ordovician-Middle(?) Ordovician-Late(?) Silurian(?) Devonian(?) Carboniferous Mississippian-Early(?) Mississippian-Middle(?) Mississippian-Late)
FORT SMITH- Mississisippian, Devonian, Silurian, and Ordovician Rocks, Undifferentiated Mississippian and Devonian. "Chattanooga Shale," shale. Devonian. "Sallisaw Formation," limestone, sandstone, and chert; and "Frisco Formation," limestone. Silurian. "Quarry Mountain Formation," limestone; "Tenkiller Formation," limestone; and "Blackgum Formation," limestone and dolomite. Ordovician. "Sylvan Shale," shale; "Fernvale Limestone," limestone; "Fite Limestone," limestone; "Tyner Formation," shale, sandstone, dolomite, and limestone; "Burgen Sandstone," sandstone and minor shales and limestones; and "Cotter Dolomite," dolomite.
Union Valley Formation (with sandstone) (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early)
ARDMORE-SHERMAN- Limestone, gray, fine- to medium-grained, IPul, 12 to 25 feet thick; with sandstone, IPus, below, fine- to medium-grained, about 150 to 260 feet thick. Occurs in the ARBUCKLE MTNS
Upper Holdenville Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
ENID- Mainly shale with interbedded fine-grained sandstone locally containing beds of limestone. Only a few feet is exposed in quadrangle
Vamoosa Group or Vamoosa Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late)
ENID- "Vamoosa Group"- Alternating layers of shale and fine- to coarse-grained sandstone, with some thin limestones. Sandstone layers are thicker, coarser grained, and more numerous southward. Group near Kansas border includes (descending): unnamed shale and sandstone (160 feet thick) at top, "Plattsmouth Limestone, "IPvap (14 to 23 feet thick), unnamed shale and sandstone (15 to 90 feet thick), "Leavenworth Limestone," IPvale (4 feet thick), unnamed shale and sandstone (170 feet thick) "Labadie Limestone," IPval (6 to 23 feet thick; may also be called "Haskell Limestone"), unnamed shale and sandstone (60 to 100 feet thick), "Bowring Limestone," IPvab (2 feet thick; may also be called "Westphalia Limestone"), unnamed shale (5 to 10 feet thick), and basal "Cheshewalla Sandstone (7 to 20 feet thick; also called "Tonganoxie Sandstone"). Total thickness about 630 feet (190 m) OKLAHOMA CITY- "Vamoosa Formation"- Alternating thin to massive layers of fine- to coarse-grained sandstone and sandy, silty shale containing some chert conglomerate in middle and lower parts of formation. Thickness ranges about 200 to about 690 feet. ARDMORE-SHERMAN- "Vamoosa Formation"- Shale, sandstone, and chert conglomerate; red-brown to buff fine- to coarse-grained sandstone. Subdivided into 12 members, each with coarse clastics at base overlain by shale. Thickness, about 125 to 260 feet (to 1,000 feet in subsurface), decreasing southward.
Vamoosa + Tallant + Barnsdall Formations (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
TULSA- "Vamoosa Formation," shale, sandstone, siltstone, and thin limestone. "Tallant Formation," shale, sandstone, and thin limestone. "Barnsdall Formation," shale, siltstone, sandstone, and thin limestone
Vanoss Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late)
ENID- Alternating layers of limestone and shale to north, grading southward into limestone, shale, and fine-grained arkosic sandstone. Locally group contains thin coal seams. Near Kansas border, group includes (descending): "Salem Point Shale" (12 feet thick) at top, underlain by "Burr Limestone" (8 feet thick), "Legion Shale" (4 feet thick), "Sallyards Limestone" (3 feet thick), "Roca Shale" (15 feet thick), "Red Eagle Limestone," IPvre (20 feet thick), "Johnson Shale" (35 feet thick), "Long Creek Limestone," IPvlc (10 feet thick), unnamed shale (3 feet thick), "Hughes Creek Limestone (15 feet thick), unnamed shale (12 feet thick), "Americus Limestone, "IPvam, (12 feet thick), "Oaks Shale" (3 feet thick), "Houchen Creek Limestone (8 feet thick), "Stine Shale" (20 feet thick), "Five Point Limestone" (3 feet thick), unnamed shale (12 feet thick), "Brownville Limestone, IPvb (8 feet thick), "Pony Creek Shale" (40 feet thick), "Grayhorse Limestone," IPvg (5 feet thick), unnamed shale (12 feet thick), "Nebraska City Limestone" (5 feet thick), "French Creek Shale" (12 feet thick), "Jim Creek Limestone" (3 feet thick), "Friedrich Shale" (30 feet thick), "Grandhaven Limestone" (2 feet thick), "Dry Shale" (25 feet thick), "Dover Limestone" (30 feet thick), "Willard-Langdon Shale" (110 feet thick), "Elmont Limestone," IPve (10 feet thick), "Stonebreaker Shale" (20 feet thick), and "Reading Limestone" (20 feet thick) at base. Total thickness, about 500 feet (150 m). OKLAHOMA CITY- Red-brown to gray shale and orange-brown fine-grained, crossbedded sandstone; grades southward into arkosic sandstoneand conglomerate. Includes many thin limestone beds and shale units north of North Canadian River (descending): "Roca Shale"(75 feet thick), "Red Eagle Limestone," IPvre (3 to 8 feetthick), "Johnson Shale" (60 feet thick), "Long Creek Limestone," IPvlc (9 to 12 feet thick), "Hughes Creek Shale" (52 feet thick), "Americus Limestone," IPva (1.0 to 2.5 feetthick), "Admire Shale" (70 feet thick), "BrownvilleLimestone," IPvb (1 to 3 feet thick), "Pony Creek Shale" (75 feet thick), "Grayhorse Limestone," IPvg (1 foot thick), unnamed shale (70 feet thick), "Elmont Limestone," IPve (1.2to 7.8 feet thick), "Stonebreaker Shale" (60 feet thick), and"Reading Limestone" (1.5 feet thick), at base. Totalthickness of group ranges from 250 feet in south to 490 feet in north. ARDMORE-SHERMAN- Shale, maroon, arkose, and limestone conglomerate; thickness, 250 to 900 feet (subsurface), decreasing southward. (Pontotoc Group)
Verden Sandstone Lentil of Marlow Formation (Phanerozoic | Paleozoic | Permian )
CLINTON- The "Verden Sandstone Lentil," Pmv, is a coarse-grained, calcareous, fossiliferous sandstone (2 to 10 feet thick) that occurs in the middle of the Marlow, about 25 feet below the Relay Creek Bed and 85 to 95 feet above the base. ARDMORE-SHERMAN- "Verden Sandstone Lentil," Pmv, sandstone, 10 feet thick near middle of Marlow Formation
Viola Limestone and Bromide Formation (Phanerozoic | Paleozoic | Ordovician-Late)
CLINTON- Limestone, limestone and shale interbedded, and sandstone; thickness, about 900 feet; one outlier is shown in southern part of quadrangle. Simpson and lower units are covered. LAWTON- Limestone, interbedded limestone and shale, and sandstone; thickness about 900 feet (270 m), faulted in isolated areas, top eroded, base covered.
Wann and Iola Formations or Iola Limestone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
ENID- "Wann Formation" consists of shale and fine- to medium-grained sandstone with many thin layers of fossiliferous limestone. Thickness ranges from 50 to 400 feet (15 to 122 m). "Iola Limestone" is mainly limestone, calcareous sandstone, and shale and underlies Wann. Thickness ranges 4 to 100 feet (1 to 30 m). TULSA- "Wann Formation," shale with thin sandstone and limestone. "Iola Formation," limestone and shale. OKLAHOMA CITY- "Wann Formation," shale and fine- to medium-grained sandstone; thickness, 40 to 180 feet. Underlying "Iola Limestone," mainly fine-grained calcareous sandstone and limestone with some shale; thickness, 15 to 20 feet.
Wapanucka Formation and Chickachoc Chert (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early)
ARDMORE-SHERMAN- Limestone, gray to brown, spicular, granular to oolitic; alternates with gray shale and calcareous sandstone; thickness, 270 to 720 feet. Chert content increases southeastward. Occurs in the OUACHITA MTNS McALESTER TEXARKANA- Limestone, gray to brown, oolitic to granular, with sponge-spicular chert in middle 50 to 114 feet with overlying and underlying calcareous sandstones and shales; thickness, 600 to 700 feet, pinching out in subsurface near Ti Valley Fault. Occurs in the OUACHITA MTNS, NORTH OF TI VALLEY FAULT.
Wellington Formation (Phanerozoic | Paleozoic | Permian )
ENID- Mostly red-brown shale to north, grading into fine-grained sandstone and mudstone conglomerate southward into Logan County. Thickness, about 850 feet (260 m). (Sumner Group) OKLAHOMA CITY- Red-brown shale and orange-brown fine-grained sandstone, containing much maroon mudstone conglomerate and chert conglomerate to south. Thickness ranges from about 150 feet in south to 500 feet in north. (Sumner Group) LAWTON- Maroon shale, about 130 feet (40 m) thick, with greenish-gray and black sandstone of the "Ryan Sandstone Bed" at base. (Sumner Group) ARDMORE-SHERMAN- Shale, red-brown, with several 20- to 30-foot bituminous sandstones at base ("Ryan"); thickness, about 100 to 200 feet, decreasing southeastward.
Weno Clay and Soper Limestone (Phanerozoic | Mesozoic | Cretaceous-Early )
McALESTER TEXARKANA- "Weno Clay", clay and shale, brownish-gray, with selenite gypsum; interbedded with red- to yellow-brown fine-grained sandstones; thickness, 30 to 53 feet. "Soper Limestone" at base, limestone, gray-brown to red-brown, compact, fossiliferous, with "Rastellum carinatum;" thickness, 1 to 2 feet.
West Spring Creek and Kindblade Formations (Phanerozoic | Paleozoic | Ordovician-Early)
LAWTON- "West Spring Creek Formation" and "Kindblade Formation," Owk, dolomite, dolomitic sandstone, conglomerate, and limestone; thickness, approximately 2,000 feet (600 m). (Upper part of Arbuckle Group). ARDMORE-SHERMAN- Limestone, gray to tan, fine-grained, gradational eastward into tan fine- to coarse-grained dolomite; some tan to gray sandstone and shale; thickness, 1,875 to 3,000 feet, decreasing eastward. (Arbuckle Group) Individual Fm description not found. Occurs in the ARBUCKLE MTNS
West Spring Creek Formation (Phanerozoic | Paleozoic | Ordovician-Early)
ARDMORE-SHERMAN- Limestone, gray to tan, fine-grained, gradational eastward into tan fine- to coarse-grained dolomite; some tan to gray sandstone and shale; thickness, 1,875 to 3,000 feet, decreasing eastward. (Arbuckle Group) Individual Fm description not found Occurs in the ARBUCKLE MTNS
Wetumka Shale (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
OKLAHOMA CITY- Mainly sandy, silty, laminated shale 100 to 200 feet thick FORT SMITH- Shale, minor sandstones, and minor limestones. ARDMORE-SHERMAN- Shale, blue-gray, with some sandstones and siltstones; thickness, 120 to 250 feet
Wewoka Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle)
OKLAHOMA CITY- Interbedded fine- to medium-grained sandstone and calcareous shale. Thickness ranges from 400 to 750 feet. FORT SMITH- Shale, sandstone, and minor limestones ARDMORE-SHERMAN- Shale, blue-gray, sandstone, chert conglomerate, and limestone conglomerate; thickness, 400 feet.
Whitehorse Group (Phanerozoic | Paleozoic | Permian )
CLINTON- Predominantly orange-brown, fine-grained sandstone, the "Whitehorse Group" is mapped as Pwh where separate formations have not been distinguished and as the "Rush Springs Formation" and the "Marlow Formation" where identified. "Rush Springs Formation," Pr, orange-brown, cross-bedded, fine-grained sandstone with some dolomite and gypsum beds. Thickness, about 300 feet, thinning northward to about 186 feet. The "Weatherford Gypsum Bed," Prw, is about 30 to 60 feet below the top (mapped in southeastern part only). "Marlow Formation," Pm, orange-brown, fine-grained sandstone and siltstone, about 100 to 130 feet thick, thinning northward. This formation has 2 gypsum and (or) dolomite beds in upper 20 feet--the "Emanuel Bed" (at top) and the "Relay Creek Bed" (20 feet below top). Two thin, pale shales occur; the first is 1 foot below the top ("Gracemont") and the second is 55 feet above the base (unnamed). The "Verden Sandstone Lentil," Pmv, is a coarse-grained, calcareous, fossiliferous sandstone (2 to 10 feet thick) that occurs in the middle of the Marlow, about 25 feet below the Relay Creek Bed and 85 to 95 feet above the base. LAWTON- Predominantly orange-brown, fine-grained sandstone, the "Whitehorse Group" is mapped as Pwh where separate formations have not been distinguished and as the "Rush Springs Formation" and the "Marlow Formation" where identified. "Whitehorse Group undifferentiated," Pwh, fine-grained sandstone and siltstone as much as 100 feet (30 m) thick in western part of quadrangle, interbedded with gypsum beds 3 to 10 feet (1 to 3 m) thick.
Womble Formation or Womble Shale (Phanerozoic | Paleozoic | Ordovician-Early Ordovician-Middle)
ARDMORE-SHERMAN- "Womble Shale"- Shale, black to green; thickness, 250 feet, base covered. Occurs in the OUACHITA MNTS. McALESTER TEXARKANA- "Womble Formation"- Sandstone, phyllites, and shales, greenish-gray to dark-gray to black, weathering red-brown; some black to brown cherty limestones occur in upper part; Middle Ordovician graptolites are found in upper part, and Lower Ordovician graptolites in lower part; basal part faulted; estimated thickness, 1,000 feet or more, with maximum thickness in Arkansas 3,500 feet. Occurs in POTATO HILLS, BROKEN BOW UPLIFT or ADJACENT SMALLER UPLIFTS IN SOUTHEASTERN PART OF OUACHITA MOUNTAINS
Woodbine Formation (Phanerozoic | Mesozoic | Cretaceous-Late)
McALESTER TEXARKANA- Sand, dark-green, yellowish-red, white, gray, fine- to coarse-grained, tuffaceous in upper part; crossbedded, quartzose, and brownish-red noncalcareous clay; some gravel lentils with little to no quartz and some lignites and fossil plants; rests unconformably upon successively older Cretaceous units eastward; thickness, 325 to 455 feet, increasing eastward.
Oregon
Alsea Formation (Oligocene and upper Eocene) (Late Eocene to Oligocene)
Massive to thick-bedded tuffaceous marine siltstone and fine-grained sandstone; locally concretionary. Foraminiferal assemblages assigned to the Zemorrian and upper Refugian Stages (Kleinpell, 1938; Rau, 1975) and molluscan fauna assigned (Snavely and others, 1976a) to the Lincoln and lower Blakeley Stages of Weaver and others (1944)
Clastic sedimentary rocks (Upper and Lower Cretaceous) (Early to Late Cretaceous)
Locally fossiliferous sandstone and conglomerate; marine fossils indicate Early Cretaceous (Albian) age (Jones, 1960). Includes the Hornbrook Formation of Peck and others (1956), the Grove Creek strata of Jones (1960) and Page and others (1977), Hunters Cove Formation, Cape Sebastian Sandstone, Humbug Mountain Conglomerate, and Rocky Point Formation (Dott, 1971; Blake and others, 1985) and clastic sedimentary rocks on the West Fork of the Illinois River near Waldo (Imlay and others, 1959), about 12 km south of Cave Junction
Continental sedimentary rocks (upper and middle Miocene) (Middle Miocene to Late Miocene)
Poorly sorted and poorly bedded, fine- to coarse-grained tuffaceous siltstone, sandstone, pebble conglomerate, agglomerate, volcanic cobble conglomerate, air-fall tuff, and rare basaltic andesite flows equivalent to those in unit Tba. Included in the Miocene Sardine Formation by Peck and others (1964)
Cowlitz Formation (upper and middle Eocene) (Middle Eocene to Late Eocene)
Micaceous, arkosic to basaltic marine sandstone, siltstone, and mudstone. Foraminiferal assemblages are referred to the upper Narizian Stage of Mallory (1959) in Newton and Van Atta (1976)
Fisher and Eugene Formations and correlative rocks (Oligocene and upper Eocene) (Late Eocene to Oligocene)
Thin to moderately thick bedded, coarse- to fine-grained arkosic and micaceous sandstone and siltstone, locally highly pumiceous, of the marine Eugene Formation; and coeval and older andesitic lapilli tuff, breccia, water-laid and air-fall silicic ash of the continental Fisher and Colestin Formations; upper parts of the Fisher Formation apparently lap onto and interfinger with the Eugene Formation. Megafauna in the Eugene Formation were assigned an Oligocene age by Vokes and others (1951) and foraminifers have been assigned to the upper part of the lower Refugian Stage (McDougall, 1980), or of late Eocene age. Basalt lava flows in the Fisher Formation have yielded isotopic ages as old as 40 Ma (Lux, 1982), and south of the latitude of Cottage Grove the Fisher is overlain by a welded tuff in unit Tu dated at about 35 Ma. North of Eugene, rocks of this unit are overlain unconformably by continental volcanogenic rocks of unit Tu, including an ash-flow tuff with a K-Ar age of 30.9 +/- 0.4 Ma
Marine Eugene Formation, where mapped separately (Late Eocene to Oligocene)
Marine Eugene Formation, where mapped separately (Late Eocene to Oligocene)
Marine facies (Middle Eocene to Late Eocene)
Basaltic clastic rocks and pillow lavas, locally mapped separately by Wells and others (1983). Foraminiferal assemblages are assigned to the lower part of the Narizian Stage of Mallory (1959); see Wells and others (1983) for summary
Marine facies (Middle Eocene to Late Eocene)
Basaltic clastic rocks and pillow lavas, locally mapped separately by Wells and others (1983). Foraminiferal assemblages are assigned to the lower part of the Narizian Stage of Mallory (1959); see Wells and others (1983) for summary
Marine sandstone and siltstone (middle Eocene) (Middle Eocene)
Thin- to thick-bedded, crossbedded, well-sorted, fine- to medium-grain sandstone, siltstone, and mudstone; characterized by sparse fine white mica; shallow marine depositional setting at least partly of deltaic origin. Contains foraminiferal and molluscan faunas of early middle Eocene age. Included by Diller (1898) in the upper part of the Umpqua Formation, by Baldwin (1974) and Ryberg (1984) in the Flournoy Formation of the Umpqua Group, and by Molenaar (1985) in Camas Valley and the White Tail Ridge Members of Baldwin (1974) of the Umpqua Formation
Marine sandstone, siltstone, and mudstone (lower Eocene and Paleocene?) (Paleocene to Early Eocene)
Rhythmically interbedded sandstone, siltstone, and mudstone with minor conglomerate; deposited in deep-sea fan depositional setting on submarine basalts of the Siletz River Volcanics. Contains foraminiferal faunas referred to the Penutian Stage of early Eocene age and locally contains assemblages of probable Paleocene age (McKeel and Lipps, 1975; P.D. Snavely, Jr. and David Bukry, written communication, 1980). Included by Diller (1898) in the Umpqua Formation; Baldwin (1974) and Ryberg (1984) mostly mapped unit as sedimentary rocks of the Roseburg Formation of the Umpqua Group; according to Heller and Ryberg (1983) and Molenaar (1985), may be partly correlative with the Lookingglass Formation of Baldwin (1974). Includes lower Eocene-Paleocene turbidite sedimentary rocks exposed at Five Mile Point, about 11 km north of Bandon, that are considered by Snavely and others (1980) to represent allochtonous terrane
Marine sedimentary and tuffaceous rocks (middle Miocene to upper Eocene) (Late Eocene to Middle Miocene)
Tuffaceous and arkosic sandstone, locally fossiliferous, tuffaceous siltstone, tuff, glauconitic sandstone, minor conglomerate layers and lenses, and a few thin coal beds. Includes Scappoose Formation (Trimble, 1963; Wells and others, 1983), mudstone of Oswald West (Niem and Van Atta, 1973; Wells and others, 1983), Pittsburg Bluff Formation (see Wells and others, 1983), and Smuggler Cove and Northrup Creek formations (informal names) of Niem and Niem (1985)
Marine sedimentary rocks (lower Miocene and Oligocene) (Oligocene to Early Miocene)
Fossiliferous marine tuffaceous arkosic sandstone, and lesser conglomerate, sandstone, claystone, nonmarine volcanic sedimentary rocks, and minor coal. Molluscan and vertebrate (Cetacea) fossils indicate late Oligocene and Miocene age (Orr and Miller, 1983; Miller and Orr, 1984b). Includes Butte Creek beds of Harper (1946), and several Miocene and late Oligocene units of Miller and Orr (1984a, b)
Marine sedimentary rocks (lower Pliocene? and upper Miocene) (Late Miocene to Early Pliocene)
Massive, thick-bedded sandstone with minor interbeds of siltstone; local fossiliferous conglomerate lenses. Includes principally the Empire Formation of Baldwin (in Beaulieu and Hughes, 1975), originally considered of Pliocene age, but, on the basis of contained molluscan assemblage, now restricted to a late Miocene age (Addicott, 1983)
Marine sedimentary rocks (middle and lower Miocene) (Early Miocene to Middle Miocene)
Fine- to medium-grained Marine siltstone and sandstone that commonly contains tuff beds. Includes the Astoria Formation, which is mostly micaceous and carbonaceous sandstone, and the middle Miocene Gnat Creek Formation of Niem and Niem (1985), which overlies Frenchmen Springs Member of the Wanapum Basalt east of Astoria. The Astoria Formation locally contains calcareous concretions and sulfide nodules; foraminifers in formation are assigned to the Saucesian and Relizian Stages (Kleinpell, 1938; Rau, 1981) and molluscan fossils to the Newportian Stage of Addicott (1976, 1981). Also includes Nye Mudstone, which is massive to poorly bedded siltstone and mudstone; foraminiferal assemblages assigned to the Saucesian Stage (Kleinpell, 1938; Rau, 1981) and molluscan fauna to Pillarian(?) Stage (Armentrout, 1981)
Marine sedimentary rocks (Upper Triassic? and Upper and Middle Triassic) (Early Triassic)
Black, green, and gray argillite, mudstone, and shale; graywacke, sandy limestone, tuff, and some coarse volcaniclastic rocks; chert, sandstone comprised of chert clasts, and chert pebble conglomerate; thin-bedded and massive limestone. Locally contains some interbedded lava flows, mostly spilite or keratophyre. In places metamorphosed. Invertebrate marine fauna indicates unit mostly of Late Triassic (Karnian and Norian) age. Includes the Begg and Brisbois Formations of Dickinson and Vigrass (1965; Vester Formation of Brown and Thayer, 1966) and the Rail Cabin Argillite of Dickinson and Vigrass (1965); Fields Creek Formation and Laycock and Murderers Creek Graywackes of Brown and Thayer (1966); Martin Bridge Formation and lower sedimentary series in and near the Wallowa Mountains (Prostka, 1962; Nolf, 1966); and Doyle Creek and Wild Sheep Creek Formations (Vallier, 1977). Probably partly age correlative with rocks of the Applegate Group (Wells and Peck, 1961) of southwestern Oregon
Marine siltstone, sandstone, and conglomerate (lower Eocene) (Early Eocene)
Cobble and pebble conglomerate, pebbly sandstone, lithic sandstone, siltstone, and mudstone; massive to thin bedded; shelf and slope depositional setting. Contains foraminiferal faunas referred to the Penutian Stage of early Eocene age. Included by Diller (1898) in the Umpqua Formation; Baldwin (1974) and Ryberg (1984) included it in the Lookingglass Formation of the Umpqua Group of Baldwin; may be partly a shelf and slope facies of the sedimentary rocks of the Roseburg Formation of Baldwin (1974) according to Molenaar (1985) and Heller and Ryberg (1983)
Melange (Jurassic) (Jurassic)
Structurally complex mixture of basaltic rocks, serpentinite, chert, argillite, conglomerate, silty sandstone, and lenses of marble composing the melange of the Takilma area of Smith and others (1982)
Myrtle Group (Lower Cretaceous and Upper Jurassic) (Late Jurassic to Early Cretaceous)
Conglomerate, sandstone, siltstone, and limestone. Locally fossiliferous. As shown, includes Riddle and Days Creek Formations (Imlay and others, 1959; Jones, 1969)
Nonmarine sedimentary rocks (Eocene) (Eocene)
Continentally derived conglomerate, pebble conglomerate, sandstone, siltstone, and mudstone containing abundant biotite and muscovite. Dominantly nonvolcanic; clastic material derived from underlying older rocks
Sedimentary and volcanic rocks, partly metamorphosed (Permian and Permian?) (Permian)
Epiclastic and volcaniclastic rocks, chert, limestone, and lava flows of mid- or Early Permian(?) age that are moderately to intensely metamorphosed. Includes part of Hunsaker Creek Formation of Vallier (1977), in the eastern Blue Mountains province, composed mostly of keratophyre flows, keratophyric volcaniclastic rocks and minor spilite, mudstone, and limestone. In Wheeler County, includes phyllite, chert, and fusulinid-bearing crystalline limestone of probable Early Permian (Wolfcampian?) age (Oles and Enlows, 1971), associated with phyllite, chlorite, and muscovite schist, and lawsonite-crossite blueschist (Swanson, 1969b)
Sedimentary rocks of Dothan Formation and related rocks (Lower Cretaceous and Upper Jurassic) (Late Jurassic to Late Cretaceous)
Sandstone, conglomerate, graywacke, rhythmically banded chert lenses. Includes western Dothan and Otter Point Formations of M.C. Blake, Jr. and AS. Jayko (unpublished data, 1985) in Curry and southern Coos Counties
Sedimentary rocks (Oligocene and upper Eocene) (Late Eocene to Oligocene)
Marine shale siltstone, sandstone, and conglomerate, in places partly composed of tuffaceous and basaltic debris; interbeds of arkosic, glauconitic, and quartzose sandstone. Foraminifers are referable to the Refugian and Zemorrian Stages (see marine sedimentary rocks-units Toes and Toem-of Wells and others, 1983). Includes Bastendorff Formation of Baldwin (1974)
Sedimentary rocks, partly metamorphosed (Paleozoic) (Paleozoic)
Well-bedded limestone, fossiliferous cherty limestone, calcareous and carbonaceous sandstone, chert grit, argillite, and some conglomerate. In places foliated and metamorphosed. Includes fault slivers of Devonian rocks (Kleweno and Jeffords, 1961), Coffee Creek Formation of Mississippian age, Spotted Ridge Formation of Pennsylvanian age (Merriam and Berthiaume, 1943; Mamay and Read, 1956), and Paleozoic sedimentary and metamorphosed sedimentary and volcanic rocks, including sericite schist, amphibolite, and hornblende-garnet schist of Brown and Thayer (1966)
Sedimentary rocks (Pleistocene and Pliocene) (Pliocene to Pleistocene)
Semiconsolidated lacustrine and fluvial ashy and palagonitic sedimentary rocks, mostly tuffaceous sandstone and siltstone; locally contains abundant palagonitized basaltic debris and some pebble conglomerate. Includes alluvial gravel and mudflow deposits of Walters Hill and Springwater Formations (Trimble, 1963). In places, grades laterally through palagonite tuff and breccia into basalt flows
Siletz River Volcanics and related rocks (middle and lower Eocene and Paleocene) (Paleocene to Middle Eocene)
Aphanitic to porphyritic, vesicular pillow flows, tuff-breccias, massive lava flows and sills of tholeiitic and alkalic basalt. Upper part of sequence contains numerous interbeds of basaltic siltstone and sandstone, basaltic tuff, and locally derived basalt conglomerate. Rocks of unit pervasively zeolitized and veined with calcite. Most of these rocks are of marine origin and have been interpreted as oceanic crust and seamounts (Snavely and others, 1968). Foraminiferal assemblages referred to the Ulatisian and Penutian Stages (Snavely and others, 1969); K-Ar ages range from 50.7 +/- 3.1 to 58.1 +/- 1.5 Ma (Duncan, 1982); includes the lower part of the Roseburg Formation of Baldwin (1974), which has yielded K-Ar ages as old as 62 Ma
Tillamook Volcanics (upper and middle Eocene) (Middle Eocene to Late Eocene)
Subaerial basaltic flows and breccia and submarine basaltic breccia, pillow lavas, lapilli and augite-rich tuff with interbeds of basaltic sandstone, siltstone, and conglomerate. Includes some basaltic andesite and, near the top of the sequence, some dacite. Potassium-argon ages on middle and lower parts of sequence range from about 43 to 46 Ma (Magill and others, 1981): one potassium-argon age from dacite near top of sequence is about 40 Ma (see Wells and others, 1983)
Tuffaceous sedimentary rocks and tuff (Pliocene and Miocene) (Miocene to Pliocene)
Semiconsolidated to well-consolidated mostly lacustrine tuffaceous sandstone, siltstone, mudstone, concretionary claystone, conglomerate, pumicite, diatomite, air-fall and water-deposited vitric ash, palagonitic tuff and tuff breccia, and fluvial sandstone and conglomerate. Palagonitic tuff and breccia grade laterally into altered and unaltered basalt flows of unit Tob. In places includes layers of fluvial conglomerate and, in parts of the Deschutes-Umatilla Plateau, extensive deposits of fanglomerate composed mostly of Miocene basalt debris and silt. Also includes thin, welded and nonwelded ash-flow tuffs. Vertebrate and plant fossils indicate rocks of unit are mostly of Clarendonian and Hemphillian (late Miocene and Pliocene) age. Potassium-argon ages on interbedded basalt flows and ash-flow tuffs range from about 4 to 10 Ma. Includes the Drewsey Formation of Shotwell and others (1963); sedimentary parts of the Rattlesnake Formation of Brown and Thayer (1966); an interstratified ash-flow tuff has been radiometrically dated by potassium-argon methods at about 6.6 Ma (see Fiebelkorn and others, 1983); Bully Creek Formation of Kittleman and others (1967); Dalles Formation of Newcomb (1966, 1969); Shutler Formation of Hodge (1932), McKay beds of Hogenson (1964) and Newcomb (1966) (see also Shotwell, 1956); Kern Basin Formation of Corcoran and others (1962); Rome beds of Baldwin (1976); parts of the (now obsolete) Danforth Formation of Piper and others (1939), Idaho Group of Malde and Powers (1962), Thousand Creek Beds of Merriam (1910); the Madras (or Deschutes) Formation, the "Simtustus formation" of Smith (1984), and the Yonna Formation (Newcomb, 1958). In areas west of Cascade crest, includes the Sandy River Mudstone and the Troutdale Formation of Trimble (1963) and the lower Pliocene Helvetia Formation of Schlicker and Deacon (1967)
Tuffaceous sedimentary rocks, tuffs, pumicites, and silicic flows (Miocene) (Miocene)
Moderately well indurated lacustrine and fluvial (flood-plain) deposits of tuff, pumicite, palagonite tuff, and lesser siltstone, arkosic sandstone, and pebble and cobble conglomerate. Locally contains some lignite beds. Former glass in silicic vitroclastic debris commonly crystallized and altered to secondary silica minerals, alkali feldspar, zeolites, and clay minerals. Contains some welded and nonwelded ash-flow tuffs, and minor rhyolite flows. Widespread and abundant vertebrate fossils and minor plant fossils indicate that most of unit is of middle Miocene (Barstovian) age; parts of unit between Goose Lake and Warner Valley may include rocks of early Miocene age. Locally interlayered with and locally overlies basalt and andesite flows of unit Tmb. Overlies and locally interfingers with Picture Gorge Basalt (Thayer and Brown, 1966) and with Miocene basalt south of Prineville. Includes Mascall Formation of Merriam (1901), Sucker (Succor) Creek Formation of Corcoran and others (1962) and Kittleman and others (1967), Drip Spring Formation of Kittleman and others (1965, 1967), Trout Creek Formation of Smith (1926), and "rocks of Miocene age" of Malde and Powers (1962) in the southern Owyhee Upland province. In southeast Oregon, some of these rocks represent caldera and moat-fill deposits
Tuffaceous siltstone and sandstone (upper and middle Eocene) (Middle Eocene to Late Eocene)
Thick- to thin-bedded marine tuffaceous mudstone, siltstone, and sandstone; fine to coarse grained. Contains calcareous concretions and, in places, is carbonaceous and micaceous. Includes the Nestucca Formation, which contains a foraminiferal assemblage assigned to the upper Narizian and lowermost Refugian Stages (Snavely and others, 1969; McKeel, 1980); the Spencer Formation, which contains Narizian Stage foraminifers; the Keasey Formation, which contains upper Narizian and lower Refugian Stage foraminifers (McDougall, 1975, 1980); the Coaledo and Bateman Formations of Baldwin (1974); upper Eocene sandstone of Bela (1981); and the Sager Creek formation (informal name) of Niem and Niem (1985)
Tyee Formation (middle Eocene) (Middle Eocene)
Very thick sequence of rhymically bedded, medium- to fine-grained micaceous, feldspathic, lithic, or arkosic marine sandstone and micaceous carbonaceous siltstone; contains minor interbeds of dacite tuff in upper part. Foraminiferal fauna are referred to the Ulatisian Stage (Snavely and others, 1964). Groove and flute casts indicate deposition by north-flowing turbidity currents (Snavely and others, 1964), but probable provenance of unit is southwest Idaho (Heller and others, 1985)
Volcanic and metavolcanic rocks (Upper Triassic) (Late Triassic)
Green to gray spilite and keratophyre flows and flow breccia; and subordinate amounts of coarse volcaniclastic sandstone, tuff, sandstone, siltstone, chert, conglomerate, and limestone. Marine fauna from interlayered sedimentary rocks indicates unit is mostly of Karnian (Late Triassic) age. Includes Late Triassic "andesitic and basaltic rocks" of Nolf and Taubeneck (1963), and the basaltic to rhyolitic metavolcanic rocks and interbedded sedimentary rocks of the Huntington Formation of Brooks (1979). Equivalent, in part, to unit TrPv
Yamhill Formation and related rocks (upper and middle Eocene) (Middle Eocene to Late Eocene)
Massive to thin-bedded concretionary marine siltstone and thin interbeds of arkosic, glauconitic, and basaltic sandstone; locally contains interlayered basalt lava flows and lapilli tuff. Foraminiferal assemblages in siltstone referred to the Ulatisian and lower Narizian Stages (Snavely and others, 1969; McKeel, 1980) Includes the Elkton Formation of Baldwin (1974; also see Beaulieu and Hughes, 1975), which consists of thin-bedded siltstone and minor sandstone interbeds
Yaquina Formation (lower Miocene and upper Oligocene) (Late Oligocene to Early Miocene)
Thick- to thin-bedded sandstone, conglomerate, and tuffaceous siltstone of deltaic origin; locally contains thin coal and ash beds. Conglomerate contains abundant clasts of pumice and dacitic volcanic rocks. In places includes thick lenses of marine tuffaceous siltstone and fine-grained sandstone. Foraminifers in formation assigned to the Zemorrian and lower part of the Saucesian Stages of Kleinpell (1938) and molluscan fauna to the lower Blakeley Stage of Weaver and others (1944)
Pennsylvania
Allegheny and Pottsville Formations, undivided (Pennsylvanian)
Allegheny and Pottsville Formations, undivided - Sandstone, shale, and some coal; includes lower Pottsville conglomerate and overlying strata equivalent to Allegheny Formation in north-central outliers; formational boundary not determined due to lack of correlation with Brookville-Clarion coal.
Allegheny Formation (Pennsylvanian)
Allegheny Formation - Cyclic sequences of sandstone, shale, limestone, clay, and coal; includes valuable clay deposits and Vanport Limestone; commercially valuable Freeport, Kittanning, and Brookville-Clarion coals present; base is at bottom of Brookville-Clarion coal.
Bald Eagle Formation (Ordovician)
Bald Eagle Formation - Gray to olive-gray and grayish-red, fine- to coarse-grained, crossbedded sandstone, siltstone, and shale; some conglomerate (Lost Run Member); not present east of Susquehanna River, except at Spitzenberg Hill area (Berks County).
Beaverdam Run Member of Catskill Formation (Devonian)
Beaverdam Run Member of Catskill Formation - Alternating olive-gray siltstone and sandstone; marine fossils.
Bellefonte and Axemann Formations, undivided (Ordovician)
Bellefonte and Axemann Formations, undivided - Includes, in descending order, the Bellefonte (Obf) and Axemann (Oa) Formations.
Bellefonte Formation (Ordovician)
Bellefonte Formation - Medium-gray, brownish-weathering, medium-bedded dolomite and minor sandstone; very fine grained Tea Creek Member above, and crystalline Coffee Run Member below.
Berea Sandstone through Riceville Formation, undivided (Devonian)
Berea Sandstone through Riceville Formation, undivided - Sandstone, siltstone, and shale; mostly light to dark gray, but some sandstone is greenish yellow, and a few reddish shales occur. Includes, in descending order: Berea Sandstone, Bedford Shale, Cussewago Sandstone, and Riceville Shale; marine fossils common.
Berea Sandstone through Venango Formation, undivided (Devonian)
Berea Sandstone through Venango Formation, undivided - Greenish-yellow and gray sandstone, siltstone, and shale succession, becoming more shaly and more gray downward; bottom of interval is bottom of Panama Conglomerate; Venango not mapped separately because upper key bed (Woodcock Sandstone) is missing. Includes, in descending order: Berea Sandstone, Bedford Shale, Cussewago Sandstone, Riceville Shale, and Venango Formation equivalent; contains marine fossils.
Berry Run and Sawmill Run Members of Catskill Formation, undivided (Devonian)
Berry Run and Sawmill Run Members of Catskill Formation, undivided - Greenish-gray to gray sandstone and minor red siltstone and mudstone.
Bloomsburg and Mifflintown Formations, undivided (Silurian)
Bloomsburg and Mifflintown Formations, undivided - Includes, in descending order, the Bloomsburg Formation (Sb) and the Mifflintown Formation--interbedded dark-gray shale and medium-gray fossiliferous limestone; equivalent to "McKenzie" and "Rochester" of earlier workers; not present east of Harrisburg.
Bloomsburg Formation (Silurian)
Bloomsburg Formation - Grayish-red siltstone, shale, and sandstone arranged in fining-upward cycles.
Bloomsburg Formation (Silurian)
Bloomsburg Formation - Grayish-red and greenish-gray shale, siltstone, and very fine to coarse-grained sandstone; some calcareous mudstone in central Pennsylvania; thins to west and is replaced by Mifflintown beds; thickens eastward, replacing overlying Wills Creek and Tonoloway Formations and underlying Mifflintown Formation.
Buddys Run Member of Catskill Formation (Devonian)
Buddys Run Member of Catskill Formation - Grayish-red and brownish-gray siltstone, mudstone, and sandstone; some gray and dusky-yellow sandstone and siltstone; laterally equivalent to Duncannon, Clarks Ferry, and Sherman Creek Members.
Buffalo Springs Formation (Cambrian)
Buffalo Springs Formation - Light-gray to pinkish-gray, finely to coarsely crystalline limestone and interbedded dolomite; numerous siliceous and clayey laminae; stromatolitic limestone beds near top; some thin sandy beds.
Burgoon Sandstone (Mississippian)
Burgoon Sandstone - Buff, medium-grained, crossbedded sandstone; includes shale and coal; in places, contains conglomerate at base; contains plant fossils; equivalent to Pocono Formation of Ridge and Valley province.
Burgoon Sandstone through Cuyahoga Group, undifferentiated (Mississippian)
Burgoon Sandstone through Cuyahoga Group, undifferentiated - Informal unit including elements of Burgoon Sandstone and Shenango Formation plus Cuyahoga Group; correlation uncertain; contains sedimentary structures and trace fossils characteristic of tidal flats; called "Pocono" by earlier workers.
Buttermilk Falls Limestone through Esopus Formation, undivided (Devonian)
Buttermilk Falls Limestone through Esopus Formation, undivided - In descending order: Buttermilk Falls Limestone--gray fossiliferous limestone and black chert; Palmerton Sandstone--massive white siliceous sandstone; Schoharie Formation--gray calcareous, argillaceous siltstone; Esopus Formation--gray silty shale and sandy siltstone.
Casselman Formation (Pennsylvanian)
Casselman Formation - Cyclic sequences of shale, siltstone, sandstone, red beds, thin, impure limestone, and thin, nonpersistent coal; red beds are associated with landslides; base is at top of Ames limestone.
Catskill Formation (Devonian)
Catskill Formation - Grayish-red sandstone, siltstone, shale, and mudstone; locally conglomeratic; contains gray sandstone in upper part; lithologies arranged in fining-upward cycles; equivalent to the Hampshire Formation south of Pennsylvania.
Catskill Formation (Devonian)
Catskill Formation - Grayish-red sandstone, siltstone, shale, and mudstone; units of gray sandstone occur in upper part; lithologies in upper part arranged in fining-upward cycles. In the Altoona area, the Catskill Formation is mapped as the Duncannon, Sherman Creek, and Irish Valley Members, which are described under "Central and Eastern Pennsylvania" provinces.
Catskill Formation (Devonian)
Catskill Formation - Succession of grayish-red sandstone, siltstone, shale, and mudstone, generally in fining-upward cycles; some gray sandstone and conglomerate.
Chadakoin Formation (Devonian)
Chadakoin Formation - Light-gray or brownish siltstone and some sandstone, interbedded with medium-gray shale; included in Conneaut Group and "Chemung" of earlier workers; marine fossils common; includes "pink rock" of drillers.
Clarks Ferry Member of Catskill Formation (Devonian)
Clarks Ferry Member of Catskill Formation - Gray to yellowish-gray sandstone and conglomerate.
Clarks Ferry Member of Catskill Formation (Devonian)
Clarks Ferry Member of Catskill Formation - Gray to yellowish-gray sandstone, siltstone, and conglomerate.
Clinton Group (Silurian)
Clinton Group - Predominantly Rose Hill Formation--light-olive-gray to brownish-gray, fossiliferous shale; locally, limestone occurs near top; includes dark-reddish-gray, very fine to coarse-grained, ferruginous sandstone; east of Harrisburg, equivalent to Lizard Creek Member of Shawangunk Formation. Above Rose Hill is Keefer Formation--light- to dark-gray, fossiliferous sandstone, hematitic, oolitic sandstone, and shale; not recognized east of Harrisburg.
Cocalico Formation (Ordovician)
Cocalico Formation - Gray phyllitic shale, maroon shale, siltstone, and silty, siliceous shale; some interbedded argillaceous and quartzose sandstone; predominantly allochthonous, and probably closely related to Hamburg sequence, but includes some autochthonous elements.
Conemaugh Group (Pennsylvanian)
Conemaugh Group - Includes, in descending order, the Casselman Formation (PAcc) and the Glenshaw Formation (PAcg), which are described separately below. Casselman: Cyclic sequences of shale, siltstone, sandstone, red beds, thin, impure limestone, and thin, nonpersistent coal; red beds are associated with landslides; base is at top of Ames limestone. Glenshaw: Cyclic sequences of shale, sandstone, red beds, and thin limestone and coal; includes four marine limestone or shale horizons; red beds are involved in landslides; base is at top of Upper Freeport coal.
Corry Sandstone through Riceville Formation, undivided (Devonian)
Corry Sandstone through Riceville Formation, undivided - Same as Berea-through-Riceville (MDbr) interval, but uppermost sandstone unit is recognized as Corry, not Berea.
Cuyahoga Group (Mississippian)
Cuyahoga Group - Medium-gray siltstone and dark-gray shale containing interbedded light-gray, flaggy sandstone. Includes, in descending order: Meadville Shale, Sharpsville Sandstone, and Orangeville Shale; marine fossils common.
Decker Formation through Poxono Island Formation, undivided (Silurian)
Decker Formation through Poxono Island Formation, undivided -In descending order: Decker Formation--gray calcareous sandstone having lenses of calcareous conglomerate, siltstone, and shale, and lenses of limestone and dolomite (in Stroudsburg area, includes calcareous shale, limestone, and dolomite of Rondout Formation at top); Bossardville Limestone--gray argillaceous limestone and dolomitic limestone; Poxono Island Formation--thin-bedded dolomite, limestone, and shale; red shale in lower part. This undivided succession is equivalent to Keyser, Tonoloway, and Wills Creek (part) Formations of central Pennsylvania.
Duncannon Member of Catskill Formation (Devonian)
Duncannon Member of Catskill Formation - Grayish-red sandstone, siltstone, and mudstone in fining-upward cycles; conglomerate occurs at base of some cycles.
Duncannon Member of Catskill Formation (Devonian)
Duncannon Member of Catskill Formation - Grayish-red sandstone, siltstone, and mudstone in fining-upward cycles; conglomerate occurs at base of some cycles.
Foreknobs Formation (Devonian)
Foreknobs Formation - Interbedded sandstone, siltstone, and shale; gray to olive gray, red near top; substantial brownish-gray sandstone; some marine fossils; a few conglomerate beds at base and top.
Gatesburg Formation (Cambrian)
Gatesburg Formation - Gray dolomite, limestone, and sandstone. Includes the Mines Member (CAgm) and four lower members (CAgl).
Gettysburg conglomerate (Triassic)
Gettysburg conglomerate - Gray quartz conglomerate, sandstone, and red siltstone and mudstone.
Gettysburg Formation (Triassic)
Gettysburg Formation - Reddish-brown to maroon, silty mudstone and shale containing thin red sandstone interbeds; several thin beds of impure limestone.
Glenshaw Formation (Pennsylvanian)
Glenshaw Formation - Cyclic sequences of shale, sandstone, red beds, and thin limestone and coal; includes four marine limestone or shale horizons; red beds are involved in landslides; base is at top of Upper Freeport coal.
Graywacke and shale of Martinsburg Formation (Ordovician)
Graywacke and shale of Martinsburg Formation - Shale containing conspicuous graywacke; includes autochthonous sandstone and shale of Shochary Ridge.
Greene Formation (Permian)
Greene Formation - Cyclic sequences of sandstone, shale, red beds, thin limestone, and thin, impure coal; base is at top of Upper Washington limestone.
Hamilton Group (Devonian)
Hamilton Group - Includes, in descending order, the Mahantango (Dmh) and Marcellus (Dmr) Formations.
Hammer Creek conglomerate (Triassic)
Hammer Creek conglomerate - Cobble and pebble quartz conglomerate interbedded with red sandstone.
Hammer Creek Formation (Triassic)
Hammer Creek Formation - Gray and pale red, fine- to coarse-grained quartzose sandstone, siltstone, and mudstone.
Hardyston Formation (Cambrian)
Hardyston Formation - Typically light-gray, fine- to medium-grained quartzite, and feldspathic sandstone; color ranges from nearly white to dark gray; massive bedded; Scolithus present in upper part; quartz-pebble conglomerate occurs at base.
Huntley Mountain Formation (Mississippian and Devonian)
Huntley Mountain Formation - Greenish-gray and light-olive-gray, flaggy, fine-grained sandstone, siltstone, and a few red shale interbeds; includes lower "Pocono" plus "Oswayo" of earlier workers. Forms transition between Catskill Formation and Burgoon Sandstone.
Irish Valley Member of Catskill Formation (Devonian)
Irish Valley Member of Catskill Formation - Nonmarine, grayish-red siltstone and mudstone, and gray and grayish-red sandstone interbedded with minor, thin, light-olive-gray marine siltstone; arranged in fining-upward cycles. Lower part of member has conglomeratic sandstones.
Juniata and Bald Eagle Formations, undivided (Ordovician)
Juniata and Bald Eagle Formations, undivided - Includes, in descending order, the Juniata (Oj) and Bald Eagle (Obe) Formations.
Juniata Formation (Ordovician)
Juniata Formation - Grayish-red, very fine to medium-grained, crossbedded sandstone, and grayish-red siltstone and shale; merges with underlying Bald Eagle Formation to the south; not present east of Susquehanna River, except at Spitzenberg Hill area (Berks County).
Keyser Formation through Clinton Group, undivided (Devonian and Silurian)
Keyser Formation through Clinton Group, undivided - Same as Keyser-through-Mifflintown (DSkm) interval, plus Clinton Group at base. Clinton includes the following, in descending order: Keefer Formation--fossiliferous sandstone and hematitic, oolitic sandstone and shale; Rose Hill Formation--fossiliferous shale.
Keyser Formation through Mifflintown Formation, undivided (Devonian and Silurian)
Keyser Formation through Mifflintown Formation, undivided - In descending order: Keyser Formation--limestone; Tonoloway Formation--limestone and interbedded shale; Wills Creek Formation--interbedded shale, siltstone, limestone, and dolomite; Bloomsburg Formation--grayish-red and greenish-gray shale, siltstone, sandstone, and mudstone; Mifflintown Formation--interbedded shale and limestone.
Llewellyn Formation (Pennsylvanian)
Llewellyn Formation - Gray, fine- to coarse-grained sandstone, siltstone, shale, conglomerate, and numerous anthracite coals in repetitive sequences.
Lock Haven Formation (Devonian)
Lock Haven Formation - Interbedded olive-gray mudstone, siltstone, sandstone, and thin conglomerate; marine fossils throughout; "Chemung" of earlier workers. Laterally equivalent to Scherr and Foreknobs Formations.
Long Run and Walcksville Members of Catskill Formation, undivided (Devonian)
Long Run and Walcksville Members of Catskill Formation, undivided - Includes, in descending order, the Long Run (Dclr) and Walcksville (Dcw) Members of the Catskill Formation, which are described separately below.
Long Run Member of Catskill Formation (Devonian)
Long Run Member of Catskill Formation - Gray and grayish-red sandstone and grayish-red siltstone and mudstone in fining-upward cycles.
Lower members of Gatesburg Formation, undivided (Cambrian)
Lower members of Gatesburg Formation, undivided - Includes, in descending order: cyclic repetitions of sandstone and dolomite ("upper sandstone'' member); fossiliferous, laminated to massive limestone and dolomite (Ore Hill Member); cyclic repetitions of sandstone and dolomite (''lower sandstone" member); and thick-bedded crystalline dolomite (Stacy Member).
Mahantango Formation (Devonian)
Mahantango Formation - Gray, brown, and olive shale and siltstone; marine fossils. Includes the following members, in descending order: Tully-argillaceous limestone; Sherman Ridge, Montebello (sandstone), Fisher Ridge, Dalmatia, and Turkey Ridge. In south-central Pennsylvania, includes Clearville, Frame, Chaneysville, and Gander Run Members. Characterized by coarsening-upward cycles.
Mauch Chunk Formation (Mississippian)
Mauch Chunk Formation - Grayish-red shale, siltstone, sandstone, and some conglomerate; some local nonred zones. Includes Loyalhanna Member (crossbedded, sandy limestone) at base in south-central and southwestern Pennsylvania; also includes Greenbrier Limestone Member, and Wymps Gap and Deer Valley Limestones, which are tongues of the Greenbrier. Along Allegheny Front from Blair County to Sullivan County, Loyalhanna Member is greenish-gray, calcareous, crossbedded sandstone.
Monongahela Group (Pennsylvanian)
Monongahela Group - Cyclic sequences of limestone, shale, sandstone, and coal; commercial coals present; base is at bottom of Pittsburgh coal.
New Oxford Formation (Triassic)
New Oxford Formation - Light-gray to buff, commonly arkosic sandstone interbedded with red shale, mudstone, and fine-grained sandstone
Onondaga and Old Port Formations, undivided (Devonian)
Onondaga and Old Port Formations, undivided - Includes, in descending order, the Onondaga Formation (Don), Ridgeley Member of Old Port Formation (Dor), and Shriver, Mandata, Corriganville, and New Creek Members of Old Port Formation, undivided (Dosn).
Onondaga Formation through Poxono Island Formation, undivided (Devonian and Silurian)
Onondaga Formation through Poxono Island Formation, undivided - In descending order: Onondaga Formation--gray calcareous, sandy shale; Ridgeley Formation--brown sandstone; Rondout Formation--gray interbedded limestone, dolomite, and shale; Decker Formation--gray calcareous sandstone, and Andreas Red Beds at top; Bossardville Limestone--gray, mud-cracked shaly limestone; Poxono Island Formation--olive-gray, calcareous and dolomitic shale, siltstone, and sandstone.
Packerton Member of Catskill Formation (Devonian)
Packerton Member of Catskill Formation - Greenish-gray to gray sandstone and some siltstone; some laterally persistent conglomerate beds in lower part.
Pleasant Hill Formation (Cambrian)
Pleasant Hill Formation - Gray, thin-bedded, argillaceous limestone interbedded with shale, siltstone, and sandstone.
Pocono and Rockwell Formations, undivided (Mississippian and Devonian)
Pocono and Rockwell Formations, undivided: Buff, medium-grained, crossbedded sandstone and some conglomerate (Pocono), overlying buff to olive-gray, fine- to medium-grained, crossbedded sandstone containing a few beds of shale and conglomerate (Rockwell); shown in southwestern Bedford County only.
Pocono Formation (Mississippian)
Pocono Formation - Light-gray to buff or light-olive-gray, medium-grained, crossbedded sandstone and minor siltstone; commonly conglomeratic at base and in middle; medial conglomerate, where present, is used to divide into Mount Carbon and Beckville Members; equivalent to Burgoon Sandstone of Allegheny Plateau.
Poplar Gap and Packerton Members of Catskill Formation, undivided (Devonian)
Poplar Gap and Packerton Members of Catskill Formation, undivided - Includes, in descending order, the Poplar Gap (Dcpg) and Packerton (Dcp) Members of the Catskill Formation.
Poplar Gap Member of Catskill Formation (Devonian)
Poplar Gap Member of Catskill Formation - Gray and light-olive-gray sandstone, conglomerate, and siltstone containing intermittent red beds; laterally equivalent to Clarks Ferry, Sawmill Run, and Berry Run Members.
Pottsville Formation (Pennsylvanian)
Pottsville Formation - Predominantly gray sandstone and conglomerate; also contains thin beds of shale, claystone, limestone, and coal; includes Olean and Sharon conglomerates of northwestern Pennsylvania; thin marine limestones present in Beaver, Lawrence, and Mercer Counties; minable coals and commercially valuable high-alumina clays present locally.
Pottsville Formation (Pennsylvanian)
Pottsville Formation - Gray conglomerate, fine- to coarse-grained sandstone, and siltstone and shale containing minable anthracite coals. Includes three members, in descending order: Sharp Mountain--conglomerate and conglomeratic sandstone; Schuylkill--sandstone and conglomeratic sandstone; Tumbling Run--conglomeratic sandstone and sandstone.
Reedsville Formation (Ordovician)
Reedsville Formation - Olive-gray to dark-gray shale, siltstone, and fine-grained, thin-bedded sandstone having graded bedding; upper sandstone is very fossiliferous; includes Antes Formation (black calcareous shale) at base along Nittany Arch.
Ridgeley Formation through Coeymans Formation, undivided (Devonian)
Ridgeley Formation through Coeymans Formation, undivided - In descending order: Ridgeley Formation--white siliceous sandstone; Shriver Chert--gray siltstone and shale and dark-gray chert; Port Ewen Shale--dark-gray calcareous siltstone and shale; Minisink Limestone--dark-gray clayey limestone; New Scotland Formation--dark-gray fossiliferous shale and clayey limestone; Coeymans Formation--gray, clayey to sandy limestone.
Ridgeley Member of Old Port Formation (Devonian)
Ridgeley Member of Old Port Formation - Fine- to very coarse grained, light-gray sandstone ("Oriskany" of earlier workers).
Rockwell Formation (Mississippian and Devonian)
Rockwell Formation - Buff, fine- to medium-grained, crossbedded, argillaceous sandstone and dark-gray shale; includes some carbonaceous shale, sporadic conglomerate beds, and diamictite; included in lower "Pocono" of earlier workers.
Scherr Formation (Devonian)
Scherr Formation - Chiefly siltstone; some fine-grained sandstone, shale, and mudstone; light olive gray; marine fossils.
Shawangunk Formation (Silurian)
Shawangunk Formation - Light- to dark-gray, fine- to very coarse grained sandstone and conglomerate containing thin shale interbeds. Includes four members, in descending order: Tammany--conglomerate and sandstone; Lizard Creek--sandstone and red or green shale; Minsi--sandstone and conglomerate; Weiders--conglomerate. Tammany and Lizard Creek Members together are approximately equivalent to Clinton Group to the west; Minsi and Weiders Members together are equivalent to Tuscarora Formation to the west.
Shenango Formation (Mississippian)
Shenango Formation - Light-gray sandstone and some beds of medium-gray shale and siltstone; upper third of formation is more shaly; contains a few marine fossils.
Shenango Formation through Cuyahoga Group, undivided (Mississippian)
Shenango Formation through Cuyahoga Group, undivided - includes the Shenango Formation (Ms) and Cuyahoga Group (Mc), which are described separately below. Shenango: Light-gray sandstone and some beds of medium-gray shale and siltstone; upper third of formation is more shaly; contains a few marine fossils. Cuyahoga: Medium-gray siltstone and dark-gray shale containing interbedded light-gray, flaggy sandstone. Includes, in descending order: Meadville Shale, Sharpsville Sandstone, and Orangeville Shale; marine fossils common.
Shenango Formation through Oswayo Formation, undivided (Mississippian and Devonian)
Shenango Formation through Oswayo Formation, undivided - Greenish-gray, olive, and buff sandstone and siltstone, and gray shale in varying proportions; includes "Pocono" ("Knapp") and Oswayo of earlier workers; difficult lithologic distinction between Oswayo and "Knapp"- "Pocono" south and east of type area at Olean, N. Y.; contains marine fossils; includes lateral equivalents of Shenango Formation, Cuyahoga Group, Corry Sandstone, Bedford Shale, and Cussewago Sandstone, plus Oswayo Formation.
Shenango Formation through Riceville Formation, undivided (Mississippian and Devonian)
Shenango Formation through Riceville Formation, undivided - Sandstone, siltstone, and shale in varying proportions; distinguished from Shenango-through-Oswayo (MDso) interval on basis of more common gray shale in Riceville as compared with olive-colored shale and sandstone of Oswayo; contains marine fossils.
Sherman Creek Member of Catskill Formation (Devonian)
Sherman Creek Member of Catskill Formation - Alternating grayish-red mudstone and siltstone in poorly defined fining-upward cycles, and minor intervals of gray sandstone; laterally equivalent to Berry Run, Sawmill Run, Packerton, and Long Run Members of eastern Pennsylvania.
Snitz Creek and Buffalo Springs Formations, undivided (Cambrian)
Snitz Creek and Buffalo Springs Formations, undivided - Includes, in descending order, the Snitz Creek (CAsc) and Buffalo Springs (CAbs) Formations. Snitz Creek Formation - thick-bedded. medium- to coarsely crystalline dolomite; in part oolitic, containing laminated limestone and sandstone interbeds. Buffalo Springs Formation - light-gray to pinkish-gray, finely to coarsely crystalline limestone and interbedded dolomite; numerous siliceous and clayey laminae; stromatolitic limestone beds near top; some thin sandy beds.
Snitz Creek Formation (Cambrian)
Snitz Creek Formation - Thick-bedded, medium- to coarsely crystalline dolomite, in part oolitic, containing laminated limestone and sandstone interbeds.
Spechty Kopf Formation (Mississippian and Devonian)
Spechty Kopf Formation - Light- to olive-gray, fine- to medium- grained, crossbedded sandstone, siltstone, and local polymictic diamictite, pebbly mudstone, and laminite; arranged in crude fining-upward cycles in some places; locally has grayish-red shale near top and conglomerate at base and in middle.
Stockton conglomerate (Triassic)
Stockton conglomerate - Quartz cobbles set in a poorly sorted, sandy matrix; includes conglomeratic sandstone.
Stockton Formation (Triassic)
Stockton Formation - Light-gray to buff, coarse-grained, arkosic sandstone; includes reddish-brown to grayish-purple sandstone, siltstone, and mudstone.
Towamensing Member of Catskill Formation (Devonian)
Towamensing Member of Catskill Formation - Dominantly gray sandstone and some siltstone and shale; freshwater fossils.
Trimmers Rock Formation (Devonian)
Trimmers Rock Formation - Olive-gray siltstone and shale, characterized by graded bedding; marine fossils; some very fine grained sandstone in northeast; black shale of Harrell Formation at base in Susquehanna Valley.
Tuscarora Formation (Silurian)
Tuscarora Formation - Light- to medium-gray quartzite and quartzitic sandstone and minor interbedded shale and siltstone, locally conglomeratic in lower part; includes (to the northwest) interbedded red and non-red sandstone (Castanea Member) at top; east of Harrisburg, equivalent to Minsi and Weiders Members of Shawangunk Formation.
Venango Formation (Devonian)
Venango Formation - Light-gray siltstone interbedded with some flaggy, gray sandstone and some bluish-gray shale; Panama Conglomerate and Woodcock Sandstone are, respectively, the lower and upper key beds defining the formation; referred to as "Cattaraugus" by some workers; includes some red shales where it interfingers to the east and south with the Catskill Formation; marine fossils present.
Walcksville and Towamensing Members of Catskill Formation, undivided (Devonian)
Walcksville and Towamensing Members of Catskill Formation, undivided - Includes, in descending order, the Walcksville Member (Dcw) of the Catskill Formation, and the Towamensing Member (Dct).
Walcksville Member of Catskill Formation (Devonian)
Walcksville Member of Catskill Formation - Greenish-gray sandstone and red siltstone and mudstone in fining-upward cycles.
Warrior Formation (Cambrian)
Warrior Formation - Gray, thin- to medium-bedded, fossiliferous, cyclic limestone bearing stromatolites; interbedded with thick-bedded crystalline dolomite and some sandstone.
Washington Formation (Permian)
Washington Formation - Cyclic sequences of sandstone, shale, limestone, and coal; includes some red shale; base is at bottom of Washington coal.
Waynesboro Formation (Cambrian)
Waynesboro Formation - Greenish-gray and grayish-purple shale interbedded with greenish-gray sandstone and conglomerate; occurs in Henrietta fault block only.
Waynesboro Formation (Cambrian)
Waynesboro Formation - Interbedded red to purple shale and sandstone and some beds of dolomite and impure limestone.
Waynesburg Formation (Permian and Pennsylvanian)
Waynesburg Formation - Cyclic sequences of sandstone, shale, limestone, and coal; commercial coals present; base is at bottom of Waynesburg coal.
Wills Creek Formation through Mifflintown Formation, undivided (Silurian)
Wills Creek Formation through Mifflintown Formation, undivided - Includes, in descending order, the Wills Creek Formation (Swc) and Bloomsburg and Mifflintown Formations, undivided (Sbm).
Zullinger Formation (Cambrian)
Zullinger Formation - Interbanded and interlaminated limestone and dolomite, thin- to thick-bedded; stromatolitic limestone; several thin, local quartz sandstone beds.
Rhode Island
Conanicut Group - East Passage Formation (Cambro-Ordovician)
Conanicut Group - East Passage Formation - Red, orange-brown, and gray-green phyllite and thinly-bedded, nongraded sandstone and siltstone; rare limestone, and sparse volcanic rock including welded-tuff.
Conanicut Group - undifferentiated rock (Cambro-Ordovician)
Conanicut Group - undifferentiated rock - Consists of associations of the above rock types.
Narragansett Bay Group - Dighton Conglomerate (Pennsylvanian)
Narragansett Bay Group - Dighton Conglomerate - Gray conglomerate consisting predominantly of quartz clasts set in a sand-sized matrix. Minor lenses of litharenite and arkosic sandstone.
Narragansett Bay Group - Sachuest Arkose (Pennsylvanian)
Narragansett Bay Group - Sachuest Arkose - Gray, smoky-quartz granule-conglomerate, sandstone, and pebble to cobble conglomerate, interbedded with black carbonaceous phyllite. Includes some rock mapped formerly as Pondville Conglomerate.
Narragansett Bay Group - Wamsutta Formation (Pennsylvanian)
Narragansett Bay Group - Wamsutta Formation - Red sandstone, shale, and conglomerate, locally containing abundant volcanic detritus as clasts and matrix. Plant fossil localities occur in adjacent Massachusetts. Minor, but significant amounts of interstratified bimodal-composition volcanic lava flows consisting of alkalic basalt (locally pillowed) and rhyolite are present in adjacent Massachusetts.
Newport Group - Price Neck Formation (Late Proterozoic? or older?)
Newport Group - Price Neck Formation - Fine-grained graded beds of feldspathic siltstone and sandstone, interstratified with carbonate conglomerate, and ash-flow and lapilli tuff; some units may be lahar deposits.
South Carolina
Chatham Group, undivided (Triassic)
Chatham Group, undivided: conglomerate, sandstone and mudstone
South Dakota
Arikaree Group (Phanerozoic | Cenozoic | Tertiary | Eocene Oligocene)
Includes: Rosebud Formation (Miocene)- Pink siltstone with channel sandstone and concretions. Thickness up to 250 ft (76 m). Harrison Formation (Miocene)- Gray, silty sandstone and reworked volcanic ash with calcareous siltstone and marl. Thickness 180 ft (55 m). Turtle Butte Formation (Miocene)- Light-green to gray siltstone with sandstone channels containing claystone pebbles. Thickness 65 ft (20 m). Monroe Creek Formation (Oligocene)- Tan to grayish-tan, massive sandy siltstone and reworked volcanic ash. Thickness 100 ft (30 m). Sharps Formation (Oligocene)- Pink siltstone and claystone with concretionary layers, paleochannels, and beds of reworked volcanic ash. Thickness 360 ft (110 m).
Batesland Formation (Phanerozoic | Cenozoic | Tertiary | Miocene)
Tan to green, calcareous siltstone, claystone, channel sandstone, conglomerate, and arkose. Thickness up to 50 ft (15 m).
Belle Fourche Shale, Mowry Shale, Newcastle Sandstone,and Skull Creek Shale (Phanerozoic | Mesozoic | Cretaceous-Early Cretaceous-Middle(?) Cretaceous-Late)
Note: see individual unit descriptions
Cannonball Formation (Phanerozoic | Cenozoic | Tertiary | Paleocene )
Gray and tan siltstone, sandy to silty claystone, and fine-grained, calcareous clayely to silty sandstone, and abundant, round to lenticular carbonate concretions. Thickness up to 180 ft (55 m).
Carlile Shale (Phanerozoic | Mesozoic | Cretaceous-Late)
Dark-gray to black, silty to sandy shale with several zones of septarian, fossiliferous, carbonate concertions. Contains up to three sandstone beds near the middle of the formation and sandy calcareous marl at the base. Thickness 345-620 ft (105-189 m).
Fox Hills Sandstone (Phanerozoic | Mesozoic | Cretaceous-Late)
Bluish-green to green, white to dark-gray, yellow to tan, carbonaceous and iron-stained, cross-bedded, very fine- to coarse-grained, glaconitic sandstone and siltstone. Interbedded with gray and green to brown shale and silty shale. Thickness 25-400 ft (8-122 m).
Greenhorn Formation, Belle Fourche Shale, Mowry Shale, Newcastle Sandstone, Skull Creek Shale, Inyan Kara Group, Morrison Formation, Unkpapa Sandstone, Sundance Formation, Spearfish Formation, Minnekahta Limestone, Opeche Shale, Minnelusa Formation, and Pahasapa Limestone (Phanerozoic | Paleozoic Mesozoic | Carboniferous Mississippian Permian(?) Triassic(?) Jurassic(?) Cretaceous-Early(?) Cretaceous-Middle(?) Cretaceous-Late)
Note: see individual unit descriptions
Hell Creek Formation (Phanerozoic | Mesozoic | Cretaceous-Late)
Tan to brown, light- to dark-gray, "somber beds" of shale. Interbedded with brown to red carbonaceous shale, gray and brown bentonitic silty shale, and gray, brown and yellow siltstone, sandstone, and claystone-pebble conglomerate. Thickness 260-600 ft (79-183 m).
Inyan Kara Group (Phanerozoic | Mesozoic | Cretaceous-Early )
Includes: Fall River Formation- Variegated brown, red, gray to purple, calcareous, well-sorted, fine-grained sandstone, siltstone, and shale containing mica flakes. Thickness 100-200 ft (30-61 m). Lakota Formation- Yellow, brown, red-brown, gray to black silty shale, pebble conglomerate, and massive to thin-bedded, cross-bedded sandstone. Locally interbedded with fresh-water limestone and bituminous coal beds. Thickness 35-500 ft (11-152 m).
Ludlow Formation (Phanerozoic | Cenozoic | Tertiary | Paleocene )
White, tan, yellow, and gray, cross-bedded, fine- to medium-grained,silty sandstone interbedded with locally bentonitic, gray siltstone, claystone, and sandy to silty claystone. Characterized by uranium-bearing lignite beds and "clinker" beds fromed by burning coalseams. Thickness up to 420 ft (128 m).
Minnekahta Limestone and Opeche Shale (Phanerozoic | Paleozoic | Permian)
Minnekahta Limestone-Purple to gray, finely crystalline, thin- to medium-bedded limestone with varying amounts of red shale. Thickness 30-50 ft (9-15 m). Opeche Shale- Red siltstone, argillaceous sandstone and shale interbedded with caliche layers. Thickness 85-130 ft (26-40 m).
Minnelusa Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian Permian)
Variegated, yellow to red, gray to brown, pink to purple, and black, interbedded sandstone, siltstone, shale, limestone, dolomite, calcarenite, chert and brecciated beds. Thickness 394-1,175 ft (120-358 m).
Morrison Formation, Unkpapa Sandstone, Sundance Formation, and Gypsum Spring Formation (Phanerozoic | Mesozoic | Jurassic-Middle Jurassic-Late)
Morrison Formation (Late Jurassic)- Light-gray to green and variegatedred, brown, yellow, or lavender, silceous claystone, shale, and siltstone containing interbedded sandstone and fresh-water limestone lenses. Thickness up to 150 ft (46 m). Unkpapa Sandstone (Late Jurassic)- White, massive to thin-bedded, fine-grained, argillaceous sandstone. May be variegated to banded red, yellow, brown, or lavender. Thickness up to 267 ft (81 m). Sundance Formation (Late to Middle Jurassic)- Greenish-gray, yellow, tan, red to orange, and white, variegated, interbedded, fine- to coarse-grained sandstone, siltstone, clay, and limestone. Thickness 250-350 ft (76-107 m). Gypsum Springs Formation (Middle Jusassic)- Massive white gypsum and minor maroon siltstone and shale. Thickness up to 40 ft (12 m).
Mowry Shale, Newcastle Sandstone, and Skull Creek Shale (Phanerozoic | Mesozoic | Cretaceous-Early )
Mowry Shale- Black to gray, siliceous, fissile shale and siltstone containing bentonite layers, and sparse sandstone dikes and sills. Thickness 125-250 ft (38-76 m). Newcastle Sandstone- Gray, light-brown to yellow, discontinuously distributed siltstone, claystone, sandy shale, and fine-grained sandstone. Thickness up to 290 ft (88 m). Skull Creek Shale- Dark-gray to blueish-gray shale containing ferruginous, and carbonate concretions. Thickness 150-275 ft (46-84 m).
Ogallala Group (Phanerozoic | Cenozoic | Tertiary Quaternary | Miocene Pliocene(?) Pleistocene-Early)
Includes: Ash Hollow Formation- White, tan, and gray, well-cemented, calcareous sandstone and silty limestone often referred to as "mortar beds". Thickness 90-250 ft 27-76 m) Valentine Formation- Gray, unconsolidated, fine- to coarse grained, fluvial siltstone, channel sandstone, and gravel derived from western sources. Thickness 175-225 ft (53-69 m). Fort Randall Formation- Pink and gray claystone with interbedded sandstone. Also includes green to gray orthoquartzite, bentonitic clay, and conglomerate. Thickness up to 130 ft (40 m).
Pierre Shale (Phanerozoic | Mesozoic | Cretaceous-Late)
Blue-gray to dark-gray, fissile to blocky shale with persistent beds of bentonite, black organic shale, or light-brown chalky shale. Contains minor sandstone, conglomerate, and abundant carbonate and ferruginous concretions. Thickness 1,000-2,700 ft (305-823 m).
Spearfish Formation (Phanerozoic | Paleozoic Mesozoic | Permian Triassic)
Red sandy shale, siltstone, sandstone, and minor limestone. Interbedded with abundant gypsum. Thickness 328-559 ft (100-170 m).
Tongue River Formation (Phanerozoic | Cenozoic | Tertiary | Paleocene )
White, gray, and tan, massive, cross-bedded sandstone with interbedded gray, brown, and green claystone, bentonitic claystone, clayely siltstone, carbonate concretions, and lignite. Thickness up to 285 ft (87 m).
White River Group (Phanerozoic | Cenozoic | Tertiary | Eocene Oligocene)
Includes: Brule Formation (Oligocene)- White, pink, light-green, and light-brown, massive to thin-bedded, bentonitic claystone, tuffaceous siltstone, and well-bedded, calcareous, tuffaceous quartz sandstone. Thickness up to 150 ft (46 m). Chadron Formation (Eocene)- Upper beds are gray, light-brown to maroon bentonite, claystone, siltstone tuffaceous fine-grained sandstone, and local, silicified carbonate lenses. Basal portion consists of poorly cemented, white, coarse-grained arkose and conglomerate. Thickness up to 160 ft (49 m). Chamberlain Pass Formation (Eocene)- Pale olive to pale red, mottled mudstone containing white, cross-bedded channel sandstone with basal conglomerate. Thickness up to 32 ft (10 m). Slim Buttes Formation (Eocene)- White, grayish- to yellowish-orange,pale-red to pink siltstone, clayey siltstone, bentonitic claystone,medium- to fine-grained sandstone, and conglomerate. Thickness up to 48 ft (15 m).
Tennessee
Athens Shale (Ordovician)
Athens Shale - Medium- to dark-gray, calcareous, graptolitic shale; calcareous gray sandstone, siltstone, and locally fine-pebble quartz conglomerate; nodules of shaly limestone near base. Maximum thickness 1,500 feet.
Athens Shale (Ordovician)
Athens Shale - Medium- to dark-gray, calcareous, graptolitic shale; calcareous gray sandstone, siltstone, and locally fine-pebble quartz conglomerate; nodules of shaly limestone near base. Maximum thickness 1,500 feet.
Bangor Limestone and Hartselle Formation (Mississippian)
Bangor Limestone - Dark brownish-gray limestone, thick-bedded. Thickness 100 to 250 feet; and Hartselle Formation - Thin-bedded, fine-grained sandstone and greenish-gray shale interbedded with coarse limestone. Thickness 0 to 60 feet.
Bangor Limestone and Hartselle Formation (Mississippian)
Bangor Limestone - Dark brownish-gray limestone, thick-bedded. Thickness 70 to 400 feet., and Hartselle Formation - Thin-bedded, fine-grained sandstone interbedded with gray shale; with oolitic and coarse-grained limestone beds locally. Thickness 0 to 80 feet.
Bays Formation (Ordovician)
Bays Formation - Maroon, well-jointed claystone and siltstone, commonly mottled greenish, evenly bedded; light- gray sandstone beds and metabentonite in upper part. Maximum thickness 1,000 feet.
Bays Formation (Ordovician)
Bays Formation - Maroon claystone and siltstone, commonly mottled greenish, evenly bedded; to northeast, light- gray to white, thick-bedded sandstone; metabentonite in upper part. Maximum thickness 1,000 feet.
Chepultepec Dolomite (Ordovician)
Chepultepec Dolomite - Light-gray, fine-grained, well-bedded dolomite, moderately cherty; fine-grained limestone locally in upper part; quartz sandstone beds at base. Thickness about 800 feet.
Chepultepec Dolomite (Ordovician)
Chepultepec Dolomite - Light-gray, fine-grained, well-bedded dolomite, moderately cherty; fine-grained limestone locally in upper part; quartz sandstone beds at base. Average thickness about 800 feet.
Chickamauga Group, includes Upper part of Chickamauga Group (Reedsville Shale, and Unnamed limestone unit) and Middle and Lower part of Chickamauga Group (Moccasin Formation, Bays Formation, Ottosee Shale, Holston Formation, Lenoir Limestone, Athens Shale, and Sevier Shale) (Ordovician)
Chickamauga Group - In the northwest part of the Valley and Ridge a predominantly limestone sequence about 2,000 feet thick. Becomes progressively more clastic and thicker to the southeast, including Upper part of Chickamauga Group (Reedsville Shale- Greenish-gray calcareous shale. Thickness 0 to 400 feet, and Unnamed Limestone Unit - Medium-grained, fossiliferous, gray limestone, shaly in part. Thickness as much as 600 feet ) and.Middle and lower parts of Chickamauga Group (Omlc)
Chilhowee Group; Cochran Conglomerate (Cambrian)
Chilhowee Gourp; Cochran Conglomerate - Quartz-pebble conglomerate, gray pebbly arkose, siltstone and shale; irregular bedding, scour features, crossbedding common; maroon micaceous arkose and shale near middle and base. Thickness about 1,200 feet.
Chilhowee Group; Hesse Sandstone (Cambrian)
Chilhowee Group; Hesse Sandstone - White, vitreous quartzite, medium- to coarse-grained, occurs in massive ledges; Helenmode Member at top is gray to greenish sandstone and shale. Thickness about 600 feet.
Chilhowee Group, including Erwin Formation, Hesse Sandstone, Murray Shale, Nebo Sandstone, Nichols Shale, Cochran Conglomerate, Hampton Formation, and Unicoi Formation (Cambrian)
Chilhowee Group - Conformable sequence of dominantly clastic sediments. Thickness 3,000 to 7,500 feet; including Erwin Formation - White, vitreous quartzite, massive, with interbeds of dark-green silty and sandy shale, minor siltstone, and very fine-grained sandstone. Thickness 1,000 to 1,500 feet; Hesse Sandstone - White, vitreous quartzite, medium- to coarse-grained, occurs in massive ledges; Helenmode Member at top is gray to greenish sandstone and shale. Thickness about 600 feet; Murray Shale - Shale, silty, sandy, dull-green to brown, micaceous. Thickness about 500 feet; Nebo Sandstone - Medium-bedded, fine-grained, white, vitreous quartzite, in part feldspathic. Thickness 250 feet; Nichols Shale - Olive-gray to green, silty and sandy, micaceous shale and siltstone; local lenses of fine-grained feldspathic quartzite. Thickness about 700 feet; Cochran Conglomerate - Quartz-pebble conglomerate, gray pebbly arkose, siltstone and shale; irregular bedding, scour features, crossbedding common; maroon micaceous arkose and shale near middle and base. Thickness about 1,200 feet; Hampton Formation - Dark greenish-gray, silty and sandy, micaceous shale; numerous layers of medium-grained, feldspathic, thinly bedded sandstone. Thickness 500 to 2,000 feet; Unicoi Formation - Sequence of gray feldspathic sandstone, arkose, conglomerate, graywacke, siltstone and shale; greenish amygdaloidal basalt flows near middle and base. Thickness 2,000 to 5,000 feet.
Clinch Sandstone (Silurian)
Clinch Sandstone - Clean, white, well-sorted sandstone; locally gray siltstone and shale. Average thickness about 600 feet.
Cochran Conglomerate (Cambrian)
Cochran Conglomerate - Quartz-pebble conglomerate, gray pebbly arkose, siltstone and shale; irregular bedding, scour features, crossbedding common; maroon micaceous arkose and shale near middle and base. Thickness about 1,200 feet.
Conasauga Group, includes Maynardville Limestone, Nolichucky Shale, Honaker Dolomite, Maryville Limestone, Rogersville Shale, Rutledge Limestone, Pumpkin Valley Shale, Rome Formation, Shady Dolomite (Cambrian)
Conasauga Group, includes Maynardville Limestone, Nolichucky Shale, Honaker Dolomite, Maryville Limestone, Rogersville Shale, Rutledge Limestone, Pumpkin Valley Shale, Rome Formation, Shady Dolomite
Conasauga Group, including Maynardville Limestone, Nolichucky Shale, the Maryville, Rogersville, and Rutledge Formations, Pumpkin Valley Shale, Rome Formation, and Shady Dolomite (Cambrian)
Conasauga Group - Mostly shale northwest of a line connecting Etowah and Bearden (Knoxville); to the east it consists of the six formations at right [Cmn, Maynardville Limestone. Ccl including Cn, Nolichucky Shale, Cmr Maryville, Rogersville, and Rutledge Formations, and Pumpkin Valley Shale; Cr, Rome Formation, and Cs, Shady Dolomite. Thickness about 2,000 feet.
Crab Orchard Mounatins and Gizzard Group (Pennsylvanian)
Crab Orchard Mountains and Gizzard Groups - Sandstone, conglomerate, siltstone, shale, and thin coal beds. From top down Crab Orchard Mountains group includes Rockcastle Conglomerate, Vadever Formation, Newton Sandstone, Whitwell Shale, and Sewanee Conglomerate; Gizzard Group includes Signal Point Shale, Warren Point Sandstone, and Raccoon Mountain Formation. Thickness about 1,200 to 1,400 feet.
Crab Orchard Mountains and Gizzard Groups (Pennsylvanian)
Crab Orchard Mountains and Gizzard Groups - Sandstone, conglomerate, siltstone, shale, and thin coal beds. Thickness 1,200 to 1,400 feet.
Crab Orchard Mountains Group (Pennsylvanian)
Crab Orchard Mountains Group - Only the lowest formation of the group, the Sewanee Conglomerate, is preserved in the area of this sheet. Sewanee is gray to brown, medium- to coarse-grained conglomeratic sandstone, with a thin zone of ferruginous quartz- and shale-pebble conglomerate at base. Maximum preserved thickness 35 feet.
Crab Orchard Mountains Group, including Rockcastle Conglomerate, Vandever Formation, Newton Sandstone, Whitwell Shale, and Sewanee Conglomerate (Pennsylvanian)
Crab Orchard Mountains Group - Conglomerate, sandstone, siltstone, shale, and coal; from top of Rockcastle Conglomerate to base of Sewanee Conglomerate. Thickness 200 to 950 feet; including Rockcastle Conglomerate - Conglomeratic sandstone and sandstone, gray to brown, fine- to coarse-grained. Thin coal-bearing shale locally present near middle. Thickness 150 to 220 feet; Vandever Formation - Mostly shale and siltstone, dark-gray to light-brown; conglomerate or sandstone in middle to south. Lantana and Morgan Springs coals near base and top. Thickness as much as 450 feet, average about 300 feet; Newton Sandstone - Sandstone, gray to brown or pink, fine- to medium-grained, locally conglomeratic. Thickness as much as 200 feet; average about 90 feet; Whitwell Shale - Mostly dark-gray to light-brown shale, with minor siltstone; locally middle part is sandstone. Richland coal near base; Sewanee coal in upper part. Thickness as much as 220 feet, average about 75 feet; Sewanee Conglomerate - Conglomeratic sandstone and sandstone, gray to brown, fine- to coarse-grained. Thickness as much as 200 feet, average about 100 feet.
Crooked Fork Group (Pennsylvanian)
Crooked Fork Group - Shale, sandstone, siltstone, and thin coal beds; from top down group includes Poplar Creek coal, Wartburg Sandstone, Glenmary Shale, Coalfield Sandstone, Burnt Mill Shale, Crossville Sandstone, and Dorton Shale. Thickness 200 to 450 feet.
Crooked Fork Group, including Wartburg Sandstone, Glenmary Shale, Coalfield Sandstone, Burnt Mill Shale, Crossville Sandstone, Dorton Shale (Pennsylvanian)
Crooked Fork Group - Shale, sandstone, conglomerate, siltstone, and coal; from Poplar Creek coal to top of Rockcastle Conglomerate. Thickness 320 to 455 feet; Wartburg Sandstone - Sandstone, gray to brown, fine- to medium-grained, locally conglomeratic. Poplar Creek coal and thin shale at top. Thickness 0 to 50 feet; Glenmary Shale - Mostly dark-gray to light-brown shale with minor siltstone and sandstone. Thin coal near base locally. Thickness 50 to 150 feet; Coalfield Sandstone - Sandstone, gray to brown, fine- to medium-grained. Thickness 0 to 80 feet; Burnt Mill Shale - Mostly dark-gray to light-brown shale, with minor siltstone. Thin sandstone locally present near base. Hooper coal just above base. Thickness as much as 110 feet; Crossville Sandstone - Sandstone, gray to brown or pink, fine- to medium-grained, thinly and evenly bedded. Thickness 30 to 70 feet; Dorton Shale - Mostly dark-gray to light-brown shale, with minor siltstone and sandstone. Thin coal near top. Rex coal as much as 70 feet above base. Thickness as much as 150 feet.
Cross Mountain Formation (Pennsylvanian)
Cross Mountain Formation - Mostly shale, interbedded with sandstone, siltstone, and thin coal beds; base at top of Frozen Head Sandstone. Maximum preserved thickness 270 feet.
Cross Mountain Formation (Pennsylvanian)
Cross Mountain Formation - Mostly shale, interbedded with sandstone, siltstone, and thin coal beds; base at top of Frozen Head Sandstone. Maximum preserved thickness 554 feet.
Devonian Formations, includes Pegram Formation, Camden Formation, Harriman Formation, Flat Gap Limestone, and Ross Formation (Devonian)
Devonian Formations - Characterized by marked north-south facies variations. Because of pre-Chattanooga and/or pre-Cretaceous warping and erosion, the distribution and thickness of Devonian formations is very irregular. Includes Pegram Formation - Thick-bedded, gray limestone and gray sandstone. Thickness 0 to 15 feet; Camden Formation - Light-gray novaculitic chert and tripolitic clay; and minor siliceous limestone. Thickness 0 to about 100 feet; Harriman Formation - Light-gray novaculitic chert and tripolitic clay; and minor siliceous limestone. (Harriman and Camden are differentiated paleontologically.) Thickness 0 to 50 feet; Flat Gap Limestone - Thick-bedded, coarse-grained limestone, gray with red and brown grains. Thickness 0 to 55 feet; Ross Formation - Siliceous limestone; gray and variegated shale; and medium-grained glauconitic limestone. Thickness 0 to 75 feet.
Devonian Formations, including Pegram Formation, Camden Formation, Harriman Formation, Flat Gap Limestone, and Ross Formation (Devonian)
Devonian Formations - Characterized by marked north-south facies variations and by very irregular distribution. Individual formations are not uniform in thickness and have been truncated by pre-Chattanooga erosion; includes Pegram Formation - Thick-bedded, gray limestone and gray sandstone. Thickness 0 to 30 feet; Camden Formation - Light-gray novaculitic chert and tripolitic clay; and minor siliceous limestone. Thickness 0 to about 100 feet; Harriman Formation - Light-gray novaculitic chert and tripolitic clay; and minor siliceous limestone. (Harriman and Camden are differentiated paleontologically.) Thickness 0 to 50 feet; Flat Gap Limestone - Thick-bedded, coarse-grained limestone, gray with red and brown grains. Thickness 0 to 13 feet; Ross Formation - Siliceous limestone; gray and variegated shale; and medium-grained glauconitic limestone. Thickness 0 to 75 feet.
Erwin Formation (Cambrian)
Erwin Formation - White, vitreous quartzite, massive, with interbeds of dark-green silty and sandy shale, minor siltstone, and very fine-grained sandstone. Thickness 1,000 to 1,500 feet.
Fentress Formation (Pennsylvanian)
Fentress Formation - Mostly dark-gray to light-brown shale, with minor siltstone and sandstone. Wilder coal near middle. Laterally equivalent to entire Gizzard Group and all of Crab Orchard Mountains Group below Rockcastle Conglomerate. Thickness as much as 340 feet.
Gizzard Group, including Signal Point Shale, Warren Point Sandstone, and Raccoon Mountain Formation (Pennsylvanian)
Gizzard Group - Shale, siltstone, sandstone, and conglomerate; from base of Sewannee Conglomerate to top of Mississippian. Thickness 0 to 520 feet, including Signal Point Shale - Mostly dark-gray to light-brown shale, with minor siltstone. Wilder coal near top. Thickness 0 to 180 feet, average about 60 feet; Warren Point Sandstone - Sandstone and conglomeratic sandstone, gray to brown, fine- to medium-grained, locally interbedded with shale containing coal. Thickness 0 to 300 feet, thins from southeast to northwest, average thickness about 100 feet; Raccoon Mountain Formation - Shale, siltstone, and sandstone. Bon Air coal near top; White Oak and Sale Creek coals near base. Thickness 0 to 260 feet.
Gizzard Group including Warren Point Sandstone and Raccoon Mountain Formation (Pennsylvanian)
Gizzard Group - Sandstone, conglomeratic sandstone, siltstone, shale, and minor coal. Thickness 100 to 200 feet. Includes Warren Point Sandstone - Gray to brown sandstone and minor conglomeratic sandstone. Thickness 60 to 160 feet; Raccoon Mountain Formation - Siltstone, sandstone, shale, and minor coal. Thickness 0 to 65 feet.
Grainger Formation (Mississippian)
Grainger Formation - Gray to green shale with siltstone and fine-grained glauconitic sandstone; in some areas quartz-pebble conglomerate. Thickness 500 to 1,000 feet.
Grainger Formation (Mississippian)
Grainger Formation - Gray to green shale with siltstone and fine-grained glauconitic sandstone; in some areas quartz-pebble conglomerate. Thickness about 1,200 feet.
Graves Gap Formation (Pennsylvanian)
Graves Gap Formation - Shale, sandstone, siltstone, and coal; from Windrock coal to top of Pioneer Sandstone. Thickness 200 to 350 feet.
Graves Gap Formation (Pennsylvanian)
Graves Gap Formation - Shale, sandstone, siltstone, and coal; from Windrock coal to top of Pioneer Sandstone. Thickness 275 to 385 feet.
Greasy Cove Formation and Grainger Formation (Mississippian)
Greasy Cove Formation - Gray, argillaceous limestone, calcareous shale, siltstone, and fine-grained sandstone. Equivalent to Newman Limestone. Maximum preserved thickness about 400 feet; and Grainger Formation - Gray to green shale with siltstone and fine-grained glauconitic sandstone; in some areas quartz-pebble conglomerate. Thickness about 1,200 feet.
Greasy Cove Formation, includes Grainger Formation (Mississippian)
Greasy Cove Formation, includes Grainger Formation- Gray argillaceous limestone, calcareous shale, siltstone, and fine-grained sandstone. Equivalent to Newman Limestone. Maximum preserved thickness about 400 feet.
Great Smoky Group, includes Unnamed Sandstone Unit, Anakeesta Formation, Thunderhead Sandstone, and Elkmont Sandstone (Precambrian)
Great Smoky Group - Characterized by very massive layers of coarse graywacke and arkose. The formations at right have been mapped only in region of the Great Smoky Mountains. Thickness 14,000 to about 25,000 feet; includes Unnamed Sandstone Unit - Gray, coarse sandstone and fine conglomerate, similar to Thunderhead Sandstone. Thickness about 4,500 feet; Anakeesta Formation - Dark-gray, bluish-gray, and black slate with dark-gray interbeds of fine-grained sandstone. Thickness 3,000 to 4,500 feet; Thunderhead Sandstone - Coarse, gray feldspathic sandstone, graywacke, and conglomerate; occurs in massive ledges; graded bedding and blue quartz characteristic. Thickness 5,500 to 6,300 feet; Elkmont Sandstone - Coarse to fine, gray feldspathic sandstone, graywacke, and fine conglomerate; generally finer grained beds in lower part; graded bedding typical. Thickness 1,000 to 8,000 feet.
Great Smoky Group, including Anakeesta Formation, Thunderhead Sandstone, and Elkmont Sandstone (Precambrian)
Great Smoky Group - Characterized by very massive layers of coarse graywacke and arkose. The formations have been mapped only in the region of the Great Smoky Mountains. Near Ducktown, in ascending order, the Copperhill, Hughes Gap, Hothouse, and Dean Formations are recognized. Thickness 14,000 to about 40,000 feet. Includes Anakeesta Formation - Dark-gray, bluish-gray, and black slate with dark-gray interbeds of fine-grained sandstone. Thickness 3,000 to 4,500 feet; Thunderhead Sandstone - Coarse, gray feldspathic sandstone, graywacke, and conglomerate; occurs in massive ledges; graded bedding and blue quartz characteristic. Thickness 5,500 to 6,300 feet; Elkmont Sandstone - Coarse to fine, gray feldspathic sandstone, graywacke, and fine conglomerate; generally finer grained beds in lower part; graded bedding typical. Thickness 1,000 to 8,000 feet
Hampton Formation (Cambrian)
Hampton Formation - Dark greenish-gray, silty and sandy, micaceous shale; numerous layers of medium-grained, feldspathic, thinly bedded sandstone. Thickness 500 to 2,000 feet.
Hesse Sandstone (Cambrian)
Hesse Sandstone - White, vitreous quartzite, medium- to coarse-grained, occurs in massive ledges; Helenmode Member at top is gray to greenish sandstone and shale. Thickness about 600 feet.
Indian Bluff Formation (Pennsylvanian)
Indian Bluff Formation - Shale, sandstone, siltstone, and thin coal beds; from Pioneer Sandstone Member to Jellico coal. Thickness 150 to 415 feet.
Indian Bluff Formation (Pennsylvanian)
Indian Bluff Formation - Shale, sandstone, siltstone, and thin coal beds; from Pioneer Sandstone Member to Jellico coal. Thickness 150 to 250 feet.
Jonesboro Limestone (Ordovician)
Jonesboro Limestone - Dark bluish-gray, ribboned (silt and dolomite) limestone; numerous interbeds of dark-gray dolomite; quartz sandstone at base. Erosional unconformity at top. Thickness about 2,000 feet.
Jonesboro Limestone, Newala Formation, Mascot Dolomite, Kingsport Formation, Longview Dolomite, and Chepultepec Dolomite (Ordovician)
Jonesboro Limestone - Dark bluish-gray, ribboned (silt and dolomite) limestone; numerous interbeds of dark-gray dolomite; quartz sandstone at base. Erosional unconformity at top. Thickness about 2,000 feet; Newala Formation inlcuding Mascot Dolomite - Light-gray, fine-grained, well-bedded cherty dolomite; mottled (red and green) dolomite characteristic; interbeds of bluish-gray limestone in upper part; chert-matrix quartz sandstone at base. Erosional unconformity at top. Thickness 350 to 800 feet; and Kingsport Formation - Gray, fine-grained, sparingly cherty dolomite with basal dense, gray limestone sequence. Thickness about 250 feet; Longview Dolomite - Siliceous, gray, fine-grained, medium-bedded dolomite; interbeds of gray limestone in upper part. Thickness about 300 feet; Chepultepec Dolomite - Light-gray, fine-grained, well-bedded dolomite, moderately cherty; fine-grained limestone locally in upper part; quartz sandstone beds at base. Thickness about 800 feet.
Knox Group, including Jonesboro Limestone, Newala Formation, Mascot Dolomite, Kingsport Formation, Longview Dolomite, Chepultepec Dolomite, Copper Ridge Dolomite, Conococheague Limestone (Ordovician to Cambrian)
Knox Group, including (Ojb) Jonesboro Limestone - Dark bluish-gray, ribboned (silt and dolomite) limestone; numerous interbeds of dark-gray dolomite; quartz sandstone at base. Erosional unconformity at top. Thickness about 2,000 feet; (On) Newala Formation; (Oma) Mascot Dolomite - Light-gray, fine-grained, well-bedded cherty dolomite; mottled (red and green) dolomite characteristic; interbeds of bluish-gray limestone in upper part; chert-matrix quartz sandstone at base. Erosional unconformity at top. Thickness 350 to 800 feet; (Ok) Kingsport Formation - Gray, fine-grained, sparingly cherty dolomite with basal dense, gray limestone sequence. Thickness about 250 feet; (Olv) Longview Dolomite - Siliceous, gray, fine-grained, medium-bedded dolomite; interbeds of gray limestone in upper part. Thickness about 300 feet; (Oc) Chepultepec Dolomite - Light-gray, fine-grained, well-bedded dolomite, moderately cherty; fine-grained limestone locally in upper part; quartz sandstone beds at base. Thickness about 800 feet; (Ccr) Copper Ridge Dolomite - Coarse, dark-gray, knotty dolomite, asphaltic in places; with much gray, medium-grained, well- bedded dolomite; abundant chert; cryptozoans typical. Thickness about 1,000 feet.; (Ccc) Conococheague Limestone - Well-bedded, ribboned (silt and dolomite), dark-gray limestone; interbeds of fine-grained, light- to dark-gray dolomite; sparingly cherty; cryptozoans typical. Thickness about 1,500 feet.
Longview Dolomite and Chepultepec Dolomite (Ordovician)
Longview Dolomite - Siliceous, gray, fine-grained, medium-bedded dolomite; interbeds of gray limestone in upper part. Thickness about 300 feet; and Chepultepec Dolomite - Light-gray, fine-grained, well-bedded dolomite, moderately cherty; fine-grained limestone locally in upper part; quartz sandstone beds at base. Thickness about 800 feet.
Mascot Dolomite (Ordovician)
Mascot Dolomite - Light-gray, fine-grained, well-bedded cherty dolomite; mottled (red and green) dolomite characteristic; interbeds of bluish-gray limestone in upper part; chert-matrix quartz sandstone at base. Erosional unconformity at top. Thickness 350 to 800 feet.
Mascot Dolomite (Ordovician)
Mascot Dolomite - Light-gray, fine-grained, well-bedded cherty dolomite; mottled (red and green) dolomite characteristic; interbeds of bluish-gray limestone in upper part; chert-matrix quartz sandstone at base. Erosional unconformity at top. Thickness 350 to 800 feet.
Middle and Lower Parts of Chickamauga Group, including Mocassin Formation, Bays Formation, Sevier Shale, Ottosee Shale, Holston Formation, Lenoir Limestone and Athens Shale (Ordovician)
Middle and Lower Parts of Chickamauga Group - A sequence of about 1,400 feet of limestone in the northeast, which thickens and becomes more clastic to the southeast and is divided into the formations shown at right. Maximum thickness about 8,000 feet. Includes Mocassin Formation - Maroon calcareous shale, siltstone, and limestone; thin metabentonite layers in upper part; mud cracks, ripple marks common. Thickness 800 to 1,000 feet; (Ob) Bays Formation - Maroon claystone and siltstone, commonly mottled greenish, evenly bedded; to northeast, light- gray to white, thick-bedded sandstone; metabentonite in upper part. Maximum thickness 1,000 feet. (Osv) Sevier Shale - Calcareous, bluish-gray shale, weathers yellowish-brown; with thin gray limestone layers; sandstone, siltstone, and locally conglomerate to the east. Thickness 2,000 to 7,000 feet; (Oo) - Ottosee Shale - Bluish-gray calcareous shale, weathers yellow; with reef lenses of coarsely crystalline reddish fossiliferous limestone ("marble"). Thickness about 1,000 feet; (Oh) - Holston Formation - Pink, gray, and red coarsely crystalline limestone (Holston Marble); in many areas upper part is sandy, crossbedded ferruginous limestone and brown to greenish calcareous shale. Thickness 200 to 600 feet; (Ol) Lenoir Limestone - Nodular, argillaceous, gray limestone; in places basal sedimentary breccia, conglomerate, quartz sand; Mosheim Limestone Member (dense, light- to medium-gray limestone) near base. Thickness 25 to 500 feet; (Oa) Athens Shale - Medium- to dark-gray, calcareous, graptolitic shale; calcareous gray sandstone, siltstone, and locally fine-pebble quartz conglomerate; nodules of shaly limestone near base. Maximum thickness 1,500 feet.
Middle and Lower parts of Chickamauga Group, including Moccassin Formation, Bays Formation, Sevier Shale, Ottosee Shale, Holston Formation, Lenoir Limestone, and Athens Shale (Ordovician)
Middle and Lower Parts of Chickamauga Group - A sequence of about 1,400 feet of limestone in the northwest part of Valley and Ridge, which thickens and becomes more clastic to the southeast and is divided into the formations shown at right. Maximum thickness about 7,000 feet. Includes Moccasin Formation - Maroon calcareous shale, siltstone, and limestone; thin metabentonite layers in upper part; mud cracks, ripple marks common. Thickness 800 to 1,000 feet;. (Ob) Bays Formation - Maroon, well-jointed claystone and siltstone, commonly mottled greenish, evenly bedded; light- gray sandstone beds and metabentonite in upper part. Maximum thickness 1,000 feet; (Osv) Sevier Shale - Calcareous, bluish-gray shale, weathers yellowish-brown; with thin, gray limestone layers; sandstone, siltstone, and locally conglomerate to the east. Thickness 2,000 to 7,000 feet; (Oo) Ottosee Shale - Bluish-gray calcareous shale, weathers yellow; with reef lenses of coarsely crystalline reddish fossiliferous limestone ("marble"). Thickness about 1,000 feet; (Oh) Holston Formation - Pink, gray, and red coarsely crystalline limestone (Holston Marble); in many areas upper part is sandy, crossbedded ferruginous limestone and brown to greenish calcareous shale. Thickness 200 to 600 feet; (Ol) Lenoir Limestone - Nodular, argillaceous, gray limestone; in places basal sedimentary breccia, conglomerate, quartz sand; Mosheim Limestone Member (dense, light- to medium-gray limestone) near base. Thickness 25 to 500 feet; (Oa) Athens Shale - Medium- to dark-gray, calcareous, graptolitic shale; calcareous gray sandstone, siltstone, and locally fine-pebble quartz conglomerate; nodules of shaly limestone near base. Maximum thickness 1,500 feet.
Mississippian, Silurian, Devonian, and Ordovician Formations - containing all or portions of the Newman, Fort Payne, Chattanooga, Rockwood, and Sequatchie formations. (Mississippian to Ordovician)
Mississippian, Silurian, Devonian, and Ordovician Formations - Structurally complex area containing all or portions of the Newman, Fort Payne, Chattanooga, Rockwood, and Sequatchie formations.
Newala Formation, including Mascot Dolomite and Kingsport Formation (Ordovician)
(On) Newala Formation, including (Oma) Mascot Dolomite - Light-gray, fine-grained, well-bedded cherty dolomite; mottled (red and green) dolomite characteristic; interbeds of bluish-gray limestone in upper part; chert-matrix quartz sandstone at base. Erosional unconformity at top. Thickness 350 to 800 feet; and (Ok) Kingsport Formation - Gray, fine-grained, sparingly cherty dolomite with basal dense, gray limestone sequence. Thickness about 250 feet.
Newala Formation, including Mascot Dolomite and Kingsport Formation (Ordovician)
Newala Formation includes Mascot Dolomite - Light-gray, fine-grained, well-bedded cherty dolomite; mottled (red and green) dolomite characteristic; interbeds of bluish-gray limestone in upper part; chert-matrix quartz sandstone at base. Erosional unconformity at top. Thickness 350 to 800 feet; and Kingsport Formation - Gray, fine-grained, sparingly cherty dolomite with basal dense, gray limestone sequence. Thickness about 250 feet.
Newman Limestone (Mississippian)
Newman Limestone - Gray limestone sequence near Cumberland Plateau; shaly and silty limestone with minor sandstone and shale in the area of Clinch Mountain. Thickness 600 to 3,000 feet.
Newman Limestone (Mississippian)
Newman Limestone - Gray limestone sequence near Cumberland Plateau and on Whiteoak Mountain. Shaly limestone, shale, siltstone, and sandstone on Chilhowee Mountain. Thickness about 700 feet.
Ocoee Supergroup, including Walden Creek Group, (including Sandsuck Formation, Wilhite Formation, Shields Formation, Licklog Formation), Cades Sandstone, and Rich Butt Sandstone (Precambrian)
Ocoee Supergroup - Terrigenous clastic sedimentary rocks, for the most part poorly sorted and coarse. The groups are subdivided into formations only in the region of the Great Smoky Mountains. Thickness as much as 50,000 feet. Includes Walden Creek Group - The formations, other than the Sandsuck, have been mapped only in the region of the Great Smoky Mountains. Thickness about 8,000 feet; Sandsuck Formation - Olive-green and gray, argillaceous, micaceous shale with coarse feldspathic sandstone and quartz- pebble conglomerate. Thickness about 2,000 feet; Wilhite Formation - Gray to green siltstone and slate with interbeds of pebble conglomerate, sandstone, and quartzite. Thickness about 4,000 feet; Shields Formation - Massive conglomerate, sandstone, argillaceous slate; conglomerate (pebbles of various rock types) characteristic. Thickness about 1,500 feet; Licklog Formation - Feldspathic sandstone, greenish phyllite, and bluish-gray slate. Thickness about 1,500 feet; and the Cades Sandstone - Gray, well-bedded, fine- to medium-grained feldspathic metasandstone, with interbeds of dark slate and metasiltstone; precise stratigraphic position unknown. Thickness about 1,500 feet; and Rich Butt Sandstone - Gray, massive beds of feldspathic, fine- to medium-grained sandstone, with interbeds of dark slate and arkosic conglomerate; exact stratigraphic position unknown. Thickness about 1,500 feet.
Pennington Formation (Mississippian)
Pennington Formation - Highly variegated clay shale distinctive; contains siltstone beds and locally gray, fine-grained sandstone. Thickness 300 to 500 feet near Cumberland Plateau; maximum of about 1,250 feet to the east.
Pennington Formation (Mississippian)
Pennington Formation - Highly variegated clay shale, distinctive; contains siltstone and locally gray, fine-grained sandstone. Thickness 400 to 700 feet.
Pennington Formation (Mississippian)
Pennington Formation - Reddish and greenish shale and siltstone; fine-grained dolomite; dark-gray limestone; and thin-bedded sandstone. Persistent dolomite bed at base. Thickness 150 to 400 feet.
Redoak Mountain Formation (Pennsylvanian)
Redoak Mountain Formation - Shale, sandstone, silicastone, and several important coals; from Pewee coal to Windrock coal. Thickness 340 to 420 feet.
Redoak Mountain Formation (Pennsylvanian)
Redoak Mountain Formation - Shale, sandstone, siltstone, and several important coals; from Pewee coal to Windrock coal. Thickness 340 to 420 feet.
Rich Butt Sandstone (Precambrian)
Rich Butt Sandstone - Gray, massive beds of feldspathic, fine- to medium-grained sandstone, with interbeds of dark slate and arkosic conglomerate; exact stratigraphic position unknown. Thickness about 1,500 feet.
Rockcastle Conglomerate (Pennsylvanian)
Rockcastle Conglomerate - Conglomeratic sandstone and sandstone, gray to brown, fine- to coarse-grained. Thin coal-bearing shale locally present near middle. Thickness 150 to 220 feet.
Rockwood Formation (Silurian)
Rockwood Formation - Brown to maroon shale, thin gray siltstone and sandstone, and thin lenticular layers of oolitic and fossiliferous red hematite. Thickness 200 to 800 feet.
Rockwood Formation (Silurian)
Rockwood Formation - Brown to maroon shale, thin gray siltstone and sandstone, and thin lenticular layers of oolitic and fossiliferous red hematite. Thickness 350 to 550 feet.
Rockwood Formation and Clinch Sandstone (Silurian)
Rockwood Formation - Brown to maroon shale, thin gray siltstone and sandstone, and thin lenticular layers of oolitic and fossiliferous red hematite. Thickness 200 to 800 feet; and Clinch Sandstone - Clean, white, well-sorted sandstone; locally gray siltstone and shale. Combined Rockwood and Clinch thicknesses about 700 feet.
Rockwood Formation and Clinch Sandstone (Silurian)
Rockwood Formation - Brown to maroon shale, thin gray siltstone and sandstone, and thin lenticular layers of oolitic and fossiliferous red hematite. Thickness 350 to 550 feet; Clinch Sandstone - Clean, white, well-sorted sandstone; locally gray siltstone and shale. Average thickness about 600 feet.
Rome Formation (Cambrian)
Rome Foundation - Variegated (red, green, yellow) shale and siltstone; gray, fine-grained sandstone in middle and west part of Valley and Ridge; abundant limestone and dolomite in east. Thickness about 2,000 feet.
Rome Formation (Cambrian)
Rome Formation - Variegated (red, green, yellow) shale and siltstone with beds of gray, fine-grained sandstone. Maximum exposed thickness 1,500 feet.
Sandsuck Formation (Precambrian)
Sandsuck Formation - Olive-green and gray, argillaceous, micaceous shale with coarse feldspathic sandstone and quartz- pebble conglomerate. Thickness about 2,000 feet.
Sevier Shale (Ordovician)
Sevier Shale - Calcareous, bluish-gray shale, weathers yellowish-brown; with thin gray limestone layers; sandstone, siltstone, and locally conglomerate to the east. Thickness 2,000 to 7,000 feet.
Sevier Shale (Ordovician)
Sevier Shale - Calcareous, bluish-gray shale, weathers yellowish-brown; with thin, gray limestone layers; sandstone, siltstone, and locally conglomerate to the east. Thickness 2,000 to 7,000 feet.
Slatestone Formation (Pennsylvanian)
Slatestone Formation - Shale, sandstone, siltstone, and several important coals; from Jellico coal to Poplar Creek coal. Thickness 500 to 650 feet.
Slatestone Formation (Pennsylvanian)
Slatestone Formation - Shale, sandstone, siltstone, and several important coals; from Jellico coal to Poplar Creek coal. Thickness 500 to 720 feet.
Sneedville Limestone (Devonian to Silurian)
Sneedville Limestone - Gray silty limestone and dolomite, minor shale, and fine-grained, greenish-gray sandstone; fossils locally abundant. Thickness 100 to 300 feet.
Snowbird Group, including Pigeon Siltstone, Roaring Fork Sandstone, Metcalf Phyllite, Longarm Quartzite, and Wading Branch Formation (Precambrian)
Snowbird Group - The formations at right are applicable chiefly in the area of the Great Smoky Mountains. Thickness 13,000 to about 20,000 feet. Includes Pigeon Siltstone - Laminated, greenish quartzose and feldspathic siltstone; minor fine-grained gray sandstone. Thickness as much as 10,000 feet; Roaring Fork Sandstone - Interbedded massive feldspathic sandstone, greenish siltstone, and greenish phyllite. Maximum thickness 7,000 feet; Metcalf Phyllite - Lustrous, pale-green and silvery sericitic and chloritic phyllite; siltstone interbeds abundant. Thickness uncertain; at least 5,000 feet; Longarm Quartzite - Feldspathic quartzite and arkose, conspicuously light-colored, current bedded and crossbedded. Thickness about 5,000 feet; Wading Branch Formation - Medium- to dark-gray sandy slate to coarse, pebbly feldspathic sandstone and graywacke; basal part is quartz-sericite phyllite; graded bedding common. Thickness about 1,500 feet.
St. Genevieve Limestone (Mississippian)
St. Genevieve Limestone - Gray limestone, slightly oolitic and cherty, with some green shale and fine-grained sandstone. Maximum preserved thickness 70 feet. (In Western Highland Rim area only.)
St. Louis Limestone and Warsaw Limestone (Mississippian)
St. Louis Limestone - Fine-grained, brownish-gray limestone, dolomitic and cherty. Thickness 80 to 160 feet.; and Warsaw Limestone - Mainly medium- to coarse-grained, gray limestone, crossbedded. Includes much calcareous sandstone and shale to the north. Thickness 100 to 130 feet.
Unicoi Formation (Cambrian)
Unicoi Formation - Sequence of gray feldspathic sandstone, arkose, conglomerate, graywacke, siltstone and shale; greenish amygdaloidal basalt flows near middle and base. Thickness 2,000 to 5,000 feet.
Unnamed (middle part of Knox Group), including Longview Dolomite and Chepultepec Dolomite (Ordovician)
(Olc) Unnamed (middle part of Knox Group) including (Olv) Longview Dolomite - Siliceous, gray, fine-grained, medium-bedded dolomite; interbeds of gray limestone in upper part. Thickness about 300 feet.; and (Oc) Chepultepec Dolomite - Light-gray, fine-grained, well-bedded dolomite, moderately cherty; fine-grained limestone locally in upper part; quartz sandstone beds at base. Average thickness about 800 feet.
Unnamed (upper part of Knox Group), including Newala Formation, Mascot Dolomite, Kingsport Formation, Longview Dolomite, and Chepultepec Dolomite (Ordovician)
(Onc) Unnamed (upper part of the Knox Group), including the (On) Newala Formation; (Oma) Mascot Dolomite - Light-gray, fine-grained, well-bedded cherty dolomite; mottled (red and green) dolomite characteristic; interbeds of bluish-gray limestone in upper part; chert-matrix quartz sandstone at base. Erosional unconformity at top. Thickness 350 to 800 feet; (Ok) Kingsport Formation - Gray, fine-grained, sparingly cherty dolomite with basal dense, gray limestone sequence. Thickness about 250 feet. and (Olc) Unnamed (middle part of the Knox Group), including (Olv) Longview Dolomite - Siliceous, gray, fine-grained, medium-bedded dolomite; interbeds of gray limestone in upper part. Thickness about 300 feet; (Oc) Chepultepec Dolomite - Light-gray, fine-grained, well-bedded dolomite, moderately cherty; fine-grained limestone locally in upper part; quartz sandstone beds at base. Average thickness about 800 feet.
Vowell Mountain Formation (Pennsylvanian)
Vowell Mountain Formation - Shale, sandstone, siltstone, and coal; from Frozen Head Sandstone Member to Pewee coal. Thickness 230 to 375 feet.
Vowell Mountain Formation (Pennsylvanian)
Vowell Mountain Formation - Shale, sandstone, siltstone, and coal; from Frozen Head Sandstone Member to Pewee coal. Thickness 300 to 375 feet.
Walden Creek Group, including Sandsuck Formation, Wilhite Formation, Shields Formation, and Licklog Formation (Cambrian)
Walden Creek Group - The formations, other than the Sandsuck, are applicable mainly in the region of the Great Smoky Mountains. Thickness about 8,000 feet, Includes Sandsuck Formation - Olive-green and gray, argillaceous, micaceous shale with coarse feldspathic sandstone and quartz- pebble conglomerate. Thickness about 2,000 feet; Wilhite Formation - Gray to green siltstone and slate with interbeds of pebble conglomerate, sandstone, and quartzite. Thickness about 4,000 feet; Shields Formation - Massive conglomerate, sandstone, argillaceous slate; conglomerate (pebbles of various rock types) characteristic. Thickness about 1,500 feet.; Licklog Formation - Feldspathic sandstone, greenish phyllite, and bluish-gray slate. Thickness about 1,500 feet.
Walden Creek Group, including Sandsuck Formation, Wilhite Formation, Shields Formation, and Licklog Formation (Precambrian)
The formations, other than the Sandsuck, have been mapped only in the region of the Great Smoky Mountains. Thickness about 8,000 feet. Includes Sandsuck Formation - Olive-green and gray, argillaceous, micaceous shale with coarse feldspathic sandstone and quartz- pebble conglomerate. Thickness about 2,000 feet; Wilhite Formation - Gray to green siltstone and slate with interbeds of pebble conglomerate, sandstone, and quartzite. Thickness about 4,000 feet; Shields Formation - Massive conglomerate, sandstone, argillaceous slate; conglomerate (pebbles of various rock types) characteristic. Thickness about 1,500 feet; Licklog Formation - Feldspathic sandstone, greenish phyllite, and bluish-gray slate. Thickness about 1,500 feet.
Walden Creek Group; Sandsuck Formation (Precambrian)
Wladen Creek Group; Sandsuck Formation - Olive-green and gray, argillaceous, micaceous shale with coarse feldspathic sandstone and quartz- pebble conglomerate. Thickness about 2,000 feet.
Texas
Admiral and Coleman Junction Formations, undivided (Phanerozoic | Paleozoic | Permian [Wolfcamp])
Admiral and Coleman Junction Formations, undivided
Admiral Formation (Phanerozoic | Paleozoic | Permian [Wolfcamp])
Admiral Formation
Aguja Formation (Phanerozoic | Mesozoic | Cretaceous-Late)
Aguja Formation
Alta Formation (Phanerozoic | Paleozoic | Permian [Wolfcamp])
Alta Formation
Antlers Sand (Phanerozoic | Mesozoic | Cretaceous-Early)
Antlers Sand
Archer City Formation (Phanerozoic | Paleozoic | Permian [Wolfcamp])
Archer City Formation
Bell Canyon, Cherry Canyon, and Brushy Canyon Formations undivided (Phanerozoic | Paleozoic | Permian [Guadalupe])
Bell Canyon, Cherry Canyon, and Brushy Canyon Formations undivided
Bell Canyon Formation (Phanerozoic | Paleozoic | Permian [Guadalupe])
Bell Canyon Formation
Benevides Formation (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean])
Benevides Formation
Benevides Formation and Finlay Limestone, undivided (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean])
Benevides Formation and Finlay Limestone, undivided
Bigford Formation (Phanerozoic | Cenozoic | Tertiary | Eocene)
Bigford Formation
Black Peaks Member of Tornillo Formation (Phanerozoic | Cenozoic | Tertiary | Paleocene)
Black Peaks Member of Tornillo Formation
Blaine Formation (Phanerozoic | Paleozoic | Permian [Guadalupe])
Blaine Formation
Bluff Mesa Formation (Phanerozoic | Mesozoic | Cretaceous-Early)
Bluff Mesa Formation
bolson deposits (Phanerozoic | Cenozoic | Tertiary | Pliocene)
bolson deposits
Bone Spring Formation (Phanerozoic | Paleozoic | Permian [Leonard])
Bone Spring Formation
Boracho and Finlay Limestones, undivided (Phanerozoic | Mesozoic | Cretaceous-Early)
Boracho and Finlay Limestones, undivided NOTE: This unit is represented within the map unit explanation of (Geol. Map of Texas, 1992, Bur. Econ. Geol.) but does not occur on the map and is NOT included in the spatial data.
Brazos River Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Des Moines])
Brazos River Formation
Brushy Canyon Formation (Phanerozoic | Paleozoic | Permian [Guadalupe])
Brushy Canyon Formation
Buda Limestone and Eagle Mountain Sandstone, undivided (Phanerozoic | Mesozoic | Cretaceous-Late)
Buda Limestone and Eagle Mountain Sandstone, undivided
Cadell Formation (Phanerozoic | Cenozoic | Tertiary | Eocene)
Cadell Formation
Calvert Bluff Formation (Phanerozoic | Cenozoic | Tertiary | Paleocene Eocene)
Calvert Bluff Formation
Campagrande Formation (Phanerozoic | Mesozoic | Cretaceous-Early)
Campagrande Formation
Carizzo Sand (Phanerozoic | Cenozoic | Tertiary | Eocene)
Carizzo Sand
Carlsbad Group (Phanerozoic | Paleozoic | Permian [Guadalupe])
Carlsbad Group
Catahoula Formation (Phanerozoic | Cenozoic | Tertiary | Oligocene)
Catahoula Formation
Catahoula Formation and Frio Clay, undivided (Phanerozoic | Cenozoic | Tertiary | Oligocene)
Catahoula Formation and Frio Clay, undivided
Cedarton Shale and Adams Branch Limestone, undivided (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Missouri])
Cedarton Shale and Adams Branch Limestone, undivided
Cherry Canyon Formation (Phanerozoic | Paleozoic | Permian [Guadalupe])
Cherry Canyon Formation
Chinle Formation (Phanerozoic | Mesozoic | Triassic-Late)
Chinle Formation
Chisos Formation of Schiebout et al (1987) and the Big Yellow Sandstone Member of their Tornillo Formation, undivided (Phanerozoic | Cenozoic | Tertiary | Eocene Oligocene)
Chisos Formation of Schiebout et al (1987) and the Big Yellow Sandstone Member of their Tornillo Formation, undivided
Clear Fork Group (Phanerozoic | Paleozoic | Permian [Leonard])
Clear Fork Group
Cloud Chief Formation (Phanerozoic | Paleozoic | Permian [Guadalupe])
Cloud Chief Formation
Coleman Junction Formation (Phanerozoic | Paleozoic | Permian [Wolfcamp])
Coleman Junction Formation
Cook Mountain Formation (Phanerozoic | Cenozoic | Tertiary | Eocene)
Cook Mountain Formation
Cretaceous rocks, undivided (Phanerozoic | Mesozoic | Cretaceous-Late)
Cretaceous rocks, undivided
Cutoff Formation (Phanerozoic | Paleozoic | Permian [Leonard])
Cutoff Formation
Dakota and Purgatoir Formations, undivided (Phanerozoic | Mesozoic | Cretaceous-Early)
Dakota and Purgatoir Formations, undivided
Dakota Formation (Phanerozoic | Mesozoic | Cretaceous-Early Cretaceous-Late)
Dakota Formation
Delaho and Rawls Formations, undivided (Phanerozoic | Cenozoic | Tertiary | Oligocene Miocene)
Delaho and Rawls Formations, undivided NOTE: This unit is represented within the map unit explanation of (Geol. Map of Texas, 1992, Bur. Econ. Geol.) but does not occur on the map and is NOT included in the spatial data.
Delaho Formation and unit 9 of Rawls Formation (Phanerozoic | Cenozoic | Tertiary | Miocene)
Delaho Formation and unit 9 of Rawls Formation NOTE: This unit is represented within the map unit explanation of (Geol. Map of Texas, 1992, Bur. Econ. Geol.) but does not occur on the map and is NOT included in the spatial data.
Duff Formation (with Decie Member from Paisano caldera shown separately), Cottonwood Springs Basalt, Potato Hill Andesite, Sheep Canyon Basalt, Crossen Trachyte, and Pruett Formation, undivided (Phanerozoic | Cenozoic | Tertiary | Eocene-Late Oligocene-Early)
Duff Formation (with Decie Member from Paisano caldera shown separaetly), Cottonwood Springs Basalt, Potato Hill Andesite, Sheep Canyon Basalt, Crossen Trachyte, and Pruett Formation, undivided
Edwards Limestone and Antlers Sand, undivided (Phanerozoic | Mesozoic | Cretaceous-Early)
Edwards Limestone and Antlers Sand, undivided
El Paso Formation and Bliss Sandstone, undivided (Phanerozoic | Paleozoic| Cambrian-Furongian(?) Ordovician-Early)
El Paso Formation and Bliss Sandstone, undivided
El Picacho Formation (Phanerozoic | Mesozoic | Cretaceous-Late)
El Picacho Formation
El Pico Clay (Phanerozoic | Cenozoic | Tertiary | Eocene)
El Pico Clay
Escondido Formation (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian])
Escondido Formation
Espy Formation (Phanerozoic | Mesozoic | Cretaceous-Early)
Espy Formation
Finlay Limestone (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean Albian])
Finlay Limestone
Fleming Formation (Phanerozoic | Cenozoic | Tertiary | Miocene)
Fleming Formation
Fleming Formation and Oakville Sandstone, undivided (Phanerozoic | Cenozoic | Tertiary | Miocene)
Fleming Formation and Oakville Sandstone, undivided
Fredericksberg Group and Maxon Sandstone, undivided (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean])
Fredericksberg Group and Maxon Sandstone, undivided
Glen Rose Limestone (Phanerozoic | Mesozoic | Cretaceous-Early)
Glen Rose Limestone
Goat Seep Formation (Phanerozoic | Paleozoic | Permian [Guadalupe])
Goat Seep Formation
Goliad Formation (Phanerozoic | Cenozoic | Tertiary | Miocene)
Goliad Formation
Grindstone Creek Formation, expanded (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Des Moines])
Grindstone Creek Formation, expanded
Hannold Hill Member of Tornillo Formation (Phanerozoic | Cenozoic | Tertiary | Eocene)
Hannold Hill Member of Tornillo Formation
Harpersville Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Virgil])
Harpersville Formation
Hazel Formation (preCambrian-Proterozoic [Grenville])
Hazel Formation
Helms Shale, Rancheria Formation, Las Cruces Limestone, Percha Shale, and Canutillo Formations, undivided (Phanerozoic | Paleozoic | Devonian Carboniferous Mississippian-Late [Chesteran])
Helms Shale, Rancheria Formation, Las Cruces Limestone, Percha Shale, and Canutillo Formations, undivided
Hickory Sandstone Member (Phanerozoic | Paleozoic | Cambrian-Middle)
Hickory Sandstone Member
Home Creek Limestone and Colony Creek Shale, undivided (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Missouri])
Home Creek Limestone and Colony Creek Shale, undivided
Hooper Formation (Phanerozoic | Cenozoic | Tertiary | Paleocene)
Hooper Formation
Hueco Limestone (Phanerozoic | Paleozoic | Permian [Wolfcamp])
Hueco Limestone
Infiernito caldera volcanic rocks including Capote Mountain Tuff, Tsh2 of Shely Group, Buckshot Ignimbrite, and Tm1 of Morita Ranch Formation (Phanerozoic | Cenozoic | Tertiary | Eocene-Late)
Infiernito caldera volcanic rocks including Capote Mountain Tuff, Tsh2 of Shely Group, Buckshot Ignimbrite, and Tm1 of Morita Ranch Formation
Jackson Group, undivided (Phanerozoic | Cenozoic | Tertiary | Eocene Oligocene)
Jackson Group, undivided
Javelina Member of Tornillo Formation (Phanerozoic | Mesozoic Cenozoic | Cretaceous-Late Tertiary | Paleocene)
Javelina Member of Tornillo Formation
Kemp clay (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian])
Kemp clay
Kemp clay and Corsicana Marl, undivided (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian])
Kemp clay and Corsicana Marl, undivided
Kiamichi Formation (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean])
Kiamichi Formation
Laredo Formation (Phanerozoic | Cenozoic | Tertiary | Eocene-Middle)
Laredo Formation
Lazy Bend Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Des Moines])
Lazy Bend Formation
Llanoria Quartzite (preCambrian-Proterozoic [Grenville])
Llanoria Quartzite
Malone Formation (Phanerozoic | Mesozoic | Jurassic-Late)
Malone Formation
Manning Formation (Phanerozoic | Cenozoic | Tertiary | Eocene)
Manning Formation
Manning, Wellborn, and Cadell Formations, undivided (Phanerozoic | Cenozoic | Tertiary | Eocene)
Manning, Wellborn, and Cadell Formations, undivided
Markley Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian Permian)
Markley Formation
Maxon Sandstone and Bissett Conglomerate, undivided (Phanerozoic | Mesozoic | Cretaceous-Early)
Maxon Sandstone and Bissett Conglomerate, undivided NOTE: This unit is represented within the map unit explanation of (Geol. Map of Texas, 1992, Bur. Econ. Geol.) but does not occur on the map and is NOT included in the spatial data.
Maxon Sandstone and Glen Rose Limestone, undivided (Phanerozoic | Mesozoic | Cretaceous-Early)
Maxon Sandstone and Glen Rose Limestone, undivided
Mineral Wells Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Missouri])
Mineral Wells Formation
Mingus Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Des Moines])
Mingus Formation
Montoya Dolomite (Phanerozoic | Paleozoic | Ordovician-Middle Ordovician-Late)
Montoya Dolomite
Moran Formation (Phanerozoic | Paleozoic | Permian [Wolfcamp])
Moran Formation
Morrison Formation (Phanerozoic | Mesozoic | Jurassic-Late)
Morrison Formation
Munn Formation (Phanerozoic | Paleozoic | Permian [Guadalupe])
Munn Formation
Nacatoch Sand (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian])
Nacatoch Sand
Navarro and Taylor Groups, undivided (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian])
Navarro and Taylor Groups, undivided
Navarro Group and Marlbrook Marl, undivided (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian])
Navarro Group and Marlbrook Marl, undivided
Navarro Group, undivided (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian])
Navarro Group, undivided
Nocona Formation (Phanerozoic | Paleozoic | Permian [Wolfcamp Leonard])
Nocona Formation
Oakville Sandstone (Phanerozoic | Cenozoic | Tertiary | Miocene)
Oakville Sandstone
Ojinaga Formation (Phanerozoic | Mesozoic | Cretaceous-Late)
Ojinaga Formation
Olmos Formation (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian])
Olmos Formation
Palo Pinto Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Missouri])
Palo Pinto Formation
Paluxy Sand (Phanerozoic | Mesozoic | Cretaceous-Early)
Paluxy Sand
Paluxy Sand and Glen Rose Limestone, undivided (Phanerozoic | Mesozoic | Cretaceous-Early)
Paluxy Sand and Glen Rose Limestone, undivided
Pen Formation (Phanerozoic | Mesozoic | Cretaceous-Late)
Pen Formation
Perdiz Conglomerate, Tascotal Formation, and tuffaceous sediments of Fresno Formation (Phanerozoic | Cenozoic | Tertiary | Oligocene)
Perdiz Conglomerate, Tascotal Formation, and tuffaceous sediments of Fresno Formation
Permian rocks, undivided (Phanerozoic | Paleozoic | Permian)
Permian rocks, undivided
Petrolia Formation (Phanerozoic | Paleozoic | Permian [Wolfcamp Leonard])
Petrolia Formation
pre-Brazos River rocks, undivided (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Des Moines])
pre-Brazos River rocks, undivided
Presidio Formation (Phanerozoic | Mesozoic | Cretaceous-Early [Aptian Albian])
Presidio Formation
Pueblo Formation (Phanerozoic | Paleozoic | Permian [Wolfcamp])
Pueblo Formation
Quartermaster Formation (Phanerozoic | Paleozoic | Permian [Guadalupe])
Quartermaster Formation
Quaternary-Tertiary bolson deposits (Phanerozoic | Cenozoic | Tertiary Quaternary | Pliocene Pleistocene)
Quaternary-Tertiary bolson deposits
Queen City Sand (Phanerozoic | Cenozoic | Tertiary | Eocene)
Queen City Sand
Reklaw Formation (Phanerozoic | Cenozoic | Tertiary | Eocene)
Reklaw Formation
Riley Formation showing Lion Mountain Sandstone and Cap Mountain Limestone Members, undivided (Phanerozoic | Paleozoic | Cambrian-Middle)
Riley Formation showing Lion Mountain Sandstone and Cap Mountain Limestone Members, undivided
Rita Blanca Formation (Phanerozoic | Cenozoic | Tertiary | Pliocene)
Rita Blanca Formation
Rustler Formation (Phanerozoic | Paleozoic | Permian [Ochoa])
Rustler Formation
San Carlos Sandstone (Phanerozoic | Mesozoic | Cretaceous-Late)
San Carlos Sandstone
San Miguel Formation (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian])
San Miguel Formation
Santa Anna Branch Shale (Phanerozoic | Paleozoic | Permian [Wolfcamp])
Santa Anna Branch Shale
Santa Anna Branch Shale and Sedwick and Moran Formations, undivided (Phanerozoic | Paleozoic | Permian [Wolfcamp])
Santa Anna Branch Shale and Sedwick and Moran Formations, undivided
Sedwick and Moran Formations, undivided (Phanerozoic | Paleozoic | Permian [Wolfcamp])
Sedwick and Moran Formations, undivided
Sedwick Formation (Phanerozoic | Paleozoic | Permian [Wolfcamp])
Sedwick Formation
Shafter Formation (Phanerozoic | Mesozoic | Cretaceous-Early)
Shafter Formation
Smithwick Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Atoka])
Smithwick Formation
Sparta Sand (Phanerozoic | Cenozoic | Tertiary | Eocene)
Sparta Sand
Strawn Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Atoka Des Moines])
Strawn Group
Tecovas Formation (Phanerozoic | Mesozoic | Triassic-Late)
Tecovas Formation
Thrifty and Graham Formations, undivided (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Virgil])
Thrifty and Graham Formations, undivided
Travis Peak Formation (Phanerozoic | Mesozoic | Cretaceous-Early)
Travis Peak Formation
Trujillo Formation (Phanerozoic | Mesozoic | Triassic-Late)
Trujillo Formation
Twin Mountains Formation (Phanerozoic | Mesozoic | Cretaceous-Early)
Twin Mountains Formation
unnamed Pennsylvanian rocks (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian)
unnamed Pennsylvanian rocks
upper Cretaceous rocks, undivided (Phanerozoic | Mesozoic | Cretaceous-Late)
upper Cretaceous rocks, undivided
Van Horn Sandstone (preCambrian-Proterozoic [Grenville])
Van Horn Sandstone
Vieja Group, including Bracks Rhyolite, Chambers and Colmena Tuffs and Gill Breccia (Phanerozoic | Cenozoic | Tertiary | Eocene Oligocene)
Vieja Group, including Bracks Rhyolite, Chambers and Colmena Tuffs and Gill Breccia
Waggoner Ranch Formation (Phanerozoic | Paleozoic | Permian [Leonard])
Waggoner Ranch Formation
Wellborn Formation (Phanerozoic | Cenozoic | Tertiary | Eocene)
Wellborn Formation
Whitehorse Group and Blaine Formation, undivided (Phanerozoic | Paleozoic | Permian [Guadalupe])
Whitehorse Group and Blaine Formation, undivided
Whitehorse Group, undivided (Phanerozoic | Paleozoic | Permian [Guadalupe])
Whitehorse Group, undivided
Whitsett Formation (Phanerozoic | Cenozoic | Tertiary | Eocene Oligocene)
Whitsett Formation
Wilberns Formation showing San Saba Member (Phanerozoic | Paleozoic | Cambrian-Furongian)
Wilberns Formation showing San Saba Member
Wolf Mountain Shale (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Missouri])
Wolf Mountain Shale
Word Formation (Phanerozoic | Paleozoic | Permian [Guadalupe])
Word Formation
Yegua Formation (Phanerozoic | Cenozoic | Tertiary | Eocene-Middle)
Yegua Formation
Yucca Formation (Phanerozoic | Mesozoic | Cretaceous-Early)
Yucca Formation
Utah
Cambrian quartzite in Uinta Mountains-Uinta Basin area (Early to Middle Cambrian)
Cretaceous (1) sedimentary rocks in Salt Lake City-Coalville-Randolph region (Early Cretaceous)
Cretaceous (1) sedimentary rocks in southeastern Utah (Cretaceous)
Cretaceous (1) sedimentary rocks in southwestern Utah (Late Cretaceous)
Cretaceous (1) sedimentary rocks in Uinta Mountains-Uinta Basin region (Cretaceous)
Cretaceous (2) sedimentary rocks in central Utah (Cretaceous)
Cretaceous (2) sedimentary rocks in Logan-Huntsville Allochthon (Late Cretaceous)
Cretaceous (2) sedimentary rocks in Salt Lake City-Coalville-Randolph region (Late Cretaceous)
Cretaceous (2) sedimentary rocks in southeastern Utah (Late Cretaceous)
Cretaceous (2) sedimentary rocks in southwestern Utah (Late Cretaceous)
Cretaceous (2) sedimentary rocks in Uinta Mountains-Uinta Basin region (Late Cretaceous)
Cretaceous (2) sedimentary rocks in western Utah (Late Cretaceous)
Cretaceous (3) sedimentary rocks in central Utah (Late Cretaceous)
Cretaceous (3) sedimentary rocks in Salt Lake City-Coalville-Randolph region (Late Cretaceous)
Cretaceous (3) sedimentary rocks in southeastern Utah (Late Cretaceous)
Cretaceous (3) sedimentary rocks in Uinta Mountains-Uinta Basin region (Late Cretaceous)
Cretaceous (3) sedimentary rocks in western Utah (Late Cretaceous)
Cretaceous and Tertiary sedimentary rocks in central Utah (Late Cretaceous to Eocene)
Cretaceous and Tertiary sedimentary rocks in Logan-Huntsville Allochthon (Late Cretaceous to Paleocene)
Cretaceous and Tertiary sedimentary rocks in Salt Lake City-Coalville-Randolph region (Late Cretaceous to Paleocene)
Cretaceous and Tertiary sedimentary rocks in southeastern Utah (Late Cretaceous to Paleocene)
Cretaceous and Tertiary sedimentary rocks in southwestern Utah (Late Cretaceous to Paleocene)
Cretaceous and Tertiary sedimentary rocks in Uinta Mountains-Uinta Basin region (Late Cretaceous to Paleocene)
Devonian sedimentary rocks in central Utah (Devonian)
Devonian sedimentary rocks in Logan-Huntsville Allochthon (Devonian)
Devonian sedimentary rocks in Salt Lake City-Coalville-Randolph region (Devonian)
Devonian sedimentary rocks in southewestern Utah (Devonian)
Jurassic (1) sedimentary rocks in central Utah (Middle Jurassic)
Jurassic (1) sedimentary rocks in Salt Lake City-Coalville-Randolph region (Middle to Late Jurassic)
Jurassic (1) sedimentary rocks in southeastern Utah (Middle to Late Jurassic)
Jurassic (1) sedimentary rocks in southeastern Utah (Middle Jurassic)
Jurassic (1) sedimentary rocks in Uinta Mountains-Uinta Basin region (Middle to Late Jurassic)
Jurassic (2) sedimentary rocks in southeastern Utah (Late Jurassic)
Jurassic (2) sedimentary rocks in Uinta Mountains-Uinta Basin region (Late Jurassic)
Middle Cambrian shale and carbonate rocks in Salt Lake City-Coalville-Randolph region (Middle Cambrian)
Mississippian (2) sedimentary rocks in central Utah (Mississippian)
Mississippian (2) sedimentary rocks in Logan-Huntsville Allochthon (Mississippian)
Mississippian (2) sedimentary rocks in Salt Lake City-Coalville-Randolph region (Mississippian)
Mississippian (2) sedimentary rocks in Uinta Mountains-Uinta Basin region (Mississippian)
Mississippian (2) sedimentary rocks in western Utah (Mississippian)
Ordovician sedimentary rocks in western Utah (Ordovician)
Pennsylvanian and Permian sedimentary rocks in central Utah (Pennsylvanian to Permian)
Pennsylvanian and Permian sedimentary rocks in Logan-Huntsville Allochthon (Pennsylvanian to Permian)
Pennsylvanian and Permian sedimentary rocks in northwestern Utah (Pennsylvanian to Permian)
Pennsylvanian and Permian sedimentary rocks in southeastern Utah (Pennsylvanian to Permian)
Pennsylvanian and Permian sedimentary rocks in southwestern Utah (Pennsylvanian)
Pennsylvanian and Permian sedimentary rocks in western Utah (Pennsylvanian to Permian)
Pennsylvanian sedimentary rocks in Uinta Mountains-Uinta Basin region (Pennsylvanian)
Permian (1) sedimentary rocks in central Utah (Early Permian)
Permian (1) sedimentary rocks in southeastern Utah (Pennsylvanian to Early Permian)
Permian (1) sedimentary rocks in southwestern Utah (Early Permian)
Permian (1) sedimentary rocks in western Utah (Early Permian)
Permian (2) sedimentary rocks in central Utah (Permian)
Permian (2) sedimentary rocks in Salt Lake City-Coalville-Randolph region (Permian)
Permian (2) sedimentary rocks in Uinta Mountains-Uinta Basin region (Permian)
Tertiary (3) sedimentary rocks in central Utah (Late Eocene to Early Oligocene)
Tertiary (3) sedimentary rocks in southeastern Utah (Eocene)
Tertiary (3) sedimentary rocks in Uinta Mountains-Uinta Basin region (Middle Eocene to Early Oligocene)
Tertiary (4) sedimentary rocks in Logan-Huntsville Allochthon (Middle Miocene to Late Pliocene)
Tertiary (4) sedimentary rocks in northwestern Utah (Middle Miocene to Late Pliocene)
Tertiary (4) sedimentary rocks in southeastern Utah (Late Eocene)
Tertiary (4) sedimentary rocks in southwestern Utah (Miocene)
Tertiary (5) sedimentary rocks in southwestern Utah (Miocene to Pliocene)
Tertiary (5) sedimentary rocks in Uinta Mountains-Uinta Basin region (Miocene)
Triassic (1) sedimentary rocks in Salt central Utah (Early Triassic)
Triassic (1) sedimentary rocks in Salt Lake City-Coalville-Randolph region (Early Triassic)
Triassic (1) sedimentary rocks in Salt southeastern Utah (Early Triassic)
Triassic (1) sedimentary rocks in Salt southwestern Utah (Early Triassic)
Triassic (1) sedimentary rocks in Salt Uinta Mountains-Uinta Basin region (Early Triassic)
Triassic (2) sedimentary rocks in central Utah (Middle to Late Triassic)
Triassic (2) sedimentary rocks in southeastern Utah (Late Triassic)
Triassic (2) sedimentary rocks in Uinta Mountains-Uinta Basin region (Late Triassic)
Triassic (2) sedimentary rocks in western Utah (Late Triassic)
Triassic and Jurassic sedimentary rocks in central Utah (Early Jurassic)
Triassic and Jurassic sedimentary rocks in Salt Lake City-Coalville-Randolph region (Early Jurassic)
Triassic and Jurassic sedimentary rocks in southeastern Utah (Early Jurassic)
Triassic and Jurassic sedimentary rocks in southwestern Utah (Early to Middle Jurassic)
Triassic and Jurassic sedimentary rocks in Uinta Mountains-Uinta Basin region (Early Jurassic)
Triassic and Jurassic sedimentary rocks in western Utah (Early Jurassic)
Upper Cambrian carbonate rocks in Salt Lake City-Coalville-Randolph region (Middle Cambrian to Early Ordovician)
Younger Precambrian metamorphic rocks in central Utah (Proterozoic Z)
Virginia
Bluefield Formation (Mississippian)
Bluefield Formation - Calcareous shale and limestone.
Brallier Formation (Devonian)
Brallier Formation - Micaceous shale, siltstone, and sandstone.
Catoctin Formation - Metasedimentary rocks (Proterozoic Z-Cambrian)
Catoctin Formation - Metasedimentary rocks
Chattanooga Shale and Wildcat Valley Sandstone (Devonian-Mississippian)
Chattanooga Shale and Wildcat Valley Sandstone - Black, fissile shale and siltstone; calcareous sandstone
Chemung Formation (redefined as Foreknobs Formation) (Devonian)
Chemung Formation - Shale and sandstone with a few thin, quartz-pebble conglomerates and red-beds.
Chepultepec and Copper Ridge Formations (Cambrian-Ordovician)
Chepultepec and Copper Ridge Formations - Dolomite, minor limestone, chert, and calcareous sandstone.
Chilhowee Group (Cambrian)
Chilhowee Group - Appalachian Plateaus and Valley and Ridge: Quartzite, conglomerate, feldspathic sandstone, phyllite, and minor ferruginous sandstone and volcanic rocks. Blue Ridge Anticlinorium: Conglomerate, quartzite, metasiltstone, and phyllite.
Conasauga Shale (Cambrian)
Conasauga Shale - Shale with minor limestone and sandstone.
Conococheague Formation (Cambrian-Ordovician)
Conococheague Formation - Limestone, dolomite, and calcareous sandstone.
Conococheague Formation (Cambrian)
Conococheague Formation - Limestone, dolomite, and calcareous sandstone.
Cove Creek Limestone and Fido Sandstone (Mississippian)
Cove Creek Limestone and Fido Sandstone - Limestone and calcareous sandstone.
Erwin and Hampton Formations (Cambrian)
Erwin and Hampton Formations - Sandstone, quartzite, and shale.
Hampshire Formation (Devonian)
Hampshire Formation - Dusky-red to grayish-red shale, mudrock, and sandstone.
Hancock, Rose Hill, and Clinch Formations (Silurian)
Hancock, Rose Hill, and Clinch Formations - Limestone and dolomite; dusky-red and green shale and sandstone; and sandstone, shale and conglomerate.
Harlan Sandstone (Pennsylvanian)
Harlan Sandstone - Sandstone, siltstone, shale, and coal.
Juniata, Oswego, Martinsburg (Reedsville and Dolly Ridge), and Eggleston Formations (Ordovician)
Juniata, Oswego, Martinsburg (Reedsville and Dolly Ridge), and Eggleston Formations - Dusky-red shale and mudstone and sandstone; graywacke; shale and sandstone; and limestone.
Juniata, Reedsville, Trenton, and Eggleston Formations (Ordovician)
Juniata, Reedsville, Trenton, and Eggleston Formations - Dusky-red shale and mudstone and sandstone; shale and limestone. Note: one area in southeastern Bland County has landslides with intact stratigraphic units.
Kanawha Formation (Pennsylvanian)
Kanawha Formation - Sandstone, siltstone, shale, and coal.
Keefer, Rose Hill, and Tuscarora Formations (Silurian)
Keefer, Rose Hill, and Tuscarora Formations - Quartzarenite, dusky-red shale, and sandstone, Some landslides with intact stratigraphic units in Craig County area..
Knobs Formation, Paperville Shale, Lenoir and Mosheim Limestone (Ordovician)
Knobs Formation, Paperville Shale, Lenoir and Mosheim Limestone - Sandstone, conglomerate, siltstone; black, fissile shale; and limestone, in part cherty.
Knox Group (Cambrian-Ordovician)
Knox Group - dolostone, limestone, sandstone. Includes the Mascot Dolomite, Kingsport Dolomite, Chepultepec Dolomite, Copper Ridge Dolomite. (Includes: Ob, Omk, Occo, Cco, Occc.)
Lee Formation (Pennsylvanian)
Lee Formation - Quartzarenite, sandstone, conglomerate, shale, siltstone, and coal.
Lee Formation (Pennsylvanian - Mississippian)
Lee Formation - Quartzarenite, sandstone, conglomerate, shale, siltstone, and coal.
Lower Devonian and Silurian Formations Undivided (Silurian-Devonian)
Lower Devonian and Silurian Formations Undivided - Some landslides with intact stratigraphic units in Craig County area. Includes: Dsu, Skrt, Sm. (Shrc?)
Lower Devonian, Silurian and Upper Ordovician Formations Undivided (Ordovician-Devonian)
Lower Devonian, Silurian and Upper Ordovician Formations Undivided - Some landslides with intact stratigraphic units in Giles County. Includes: Skrt, Sm, Oun, Ous, Ou, Om. (Shrc, Okpl?)
Lower Ordovician and Upper Cambrian Formations Undivided (Cambrian-Ordovician)
Lower Ordovician and Upper Cambrian Formations Undivided - Includes Pinesburg Station Dolomite, Rockdale Run Formation, Beekmantown Formation, Stonehenge Limestone and Conococheague Formation.
Lynchburg Group; Charlottesville Formation (Proterozoic Z)
Lynchburg Group; Charlottesville Formation - Graphitic metasiltstone, feldspathic metasandstone, and quartzite.
Maccrady Shale (Mississippian)
Maccrady Shale - Dusky-red and green shale and mudstone; and evaporite deposits.
Maccrady Shale and Price Formation (Mississippian)
Maccrady Shale and Price Formation - Includes: Maccrady Shale: Dusky-red and green shale and mudstone; and evaporite deposits. Price Formation: Sandstone, conglomeratic sandstone, and shale with carbonaceous partings and impure coal beds.
Mahantango Formation (Devonian)
Mahantango Formation - Sandstone with interbedded shale, fossiliferous
Martinsburg and Oranda Formations (Ordovician)
Martinsburg and Oranda Formations - Shale, sandstone, siltstone, and limestone.
Millboro Shale, Huntersville Chert, and Rocky Gap Sandstone (Devonian)
Millboro Shale, Huntersville Chert, and Rocky Gap Sandstone - Black, fissile shale; chert; and calcareous sandstone
Mississippian Formations Undivided (Mississippian)
Mississippian Formations Undivided - Includes Pennington Group, Bluefield Formation, Greenbrier Limestone, Maccrady Shale and Price Formation; Includes Newman Limestone, Fort Payne Chert, and Grainger Formation in western Lee County
Moccasin or Bays Formation through Blackford Formation (Ordovician)
Moccasin or Bays Formation through Blackford Formation - Dusky-red shale and mudstone; sandstone; limestone, in part cherty; and calcareous shale.
Newark Supergroup; Arkosic Sandstone (Upper Triassic)
Arkosic sandstone
Newark Supergroup; Jurassic Interbedded Sandstone and Siltstone (Lower Jurassic)
Interbedded sandstone and siltstone
Newark Supergroup; Sandstone, undifferentiated (Upper Triassic)
Sandstone, undifferentiated
Newark Supergroup; Triassic Sandstone, Siltstone, and Shale (Upper Triassic)
Interbedded sandstone, siltstone, and shale
Newark Supergroup; Triassic Sandstone, Siltstone, Shale, and Coal (Triassic)
Interbedded sandstone, siltstone, shale and coal
New River Formation (Pennsylvanian)
New River Formation - Sandstone, siltstone, shale, and coal.
Nolichucky and Maryville Formations, Rogersville Shale, and Rutledge Formation (Cambrian)
Nolichucky and Maryville Formations, Rogersville Shale, and Rutledge Formation - Calcareous shale, limestone, and dolomite.
Norton Formation (Pennsylvanian)
Norton Formation - Shale, siltstone, sandstone, and coal.
Norton, New River, Lee and Pocahontas Formations Undivided (Pennsylvanian)
Norton, New River, Lee and Pocahontas Formations Undivided - Norton Formation: siltstone, shale, sandstone, and coal. New River Formation: Sandstone siltstone, shale, coal. Pocahontas Formation: Sandstone, siltstone, shale, and coal. Lee Formation: Quart
Pennington Group (Mississippian)
Pennington Group - Shale, sandstone, dusky-red mudstone, conglomerate, siltstone, and limestone.
Pocahontas Formation (Pennsylvanian)
Pocahontas Formation - Sandstone, siltstone, shale, and coal.
Pocono Formation (Mississippian)
Pocono Formation - Sandstone, conglomeratic sandstone, and shale with carbonaceous partings and impure coal beds.
Price Formation (Mississippian)
Price Formation - Sandstone, conglomeratic sandstone, and shale with carbonaceous partings and impure coal beds.
Ridgeley Sandstone, Helderberg and Cayugan Groups (Silurian-Devonian)
Ridgeley Sandstone, Helderberg and Cayugan Groups - Calcareous sandstone; partly cherty limestone; calcareous shale; fossiliferous.
Rome Formation (Cambrian)
Rome Formation - Dusky-red and green shale and siltstone, dolomite, and limestone.
Sequatchie Formation, Reedsville Shale, Trenton Limestone, Eggleston Formation (Ordovician)
Sequatchie Formation, Reedsville Shale, Trenton Limestone, Eggleston Formation - Shale, siltstone, limestone, and sandstone.
Silurian and Upper Ordovician Formations Undivided (Ordovician-Silurian)
Silurian and Upper Ordovician Formations Undivided - Includes: Skrt, Sm, Oun, Ous, Ou, Om. (Shrc and Okpl?)
Silurian Formations Undivided (Silurian)
Silurian Formations Undivided - Some landslides with intact stratigraphic units in Giles County area. Includes: Dsu, Skrt, Sm. (Shrc?)
Swift Run Formation (Proterozoic Z)
Swift Run Formation - Phyllite, metasandstone, and metaconglomerate.
Unicoi Formation (Cambrian)
Unicoi Formation - Sandstone and quartzite with phyllite, tuffaceous phyllite, conglomerate, and minor basalt.
Upper and Middle Ordovician Formations Undivided (Ordovician)
Upper and Middle Ordovician Formations Undivided - Includes: Oun, Ous, Ou, Om, Okpl, Oeln, Oml, Ols.
Waynesboro Formation (Cambrian)
Waynesboro Formation - Dolomite, dusky-red and green shale, limestone, and sandstone.
Waynesboro Formation and Tomstown Dolomite (Cambrian)
Waynesboro Formation and Tomstown Dolomite - Waynesboro Formation: Dolomite, dusky-red and green shale, limestone, and sandstone. Tomstown Dolomite: Dolomite, in part cherty.
Wise Formation (Pennsylvanian)
Wise Formation - Sandstone, shale, siltstone, and coal; quartzarenite.
Wise Formation and Gladeville Sandstone (Pennsylvanian)
Wise Formation and Gladeville Sandstone - Sandstone, shale, siltstone, and coal; quartzarenite.
Vermont
Bascom Formation, and undifferentiated Luke Hill, Naylor Ledge and Hastings Creek Limestones (Ordovician)
Bascom Formation, and undifferentiated Luke Hill, Naylor Ledge and Hastings Creek Limestones - Interbedded dolomite, limestone or marble, calcareous sandstone, quartzite and limestone breccia; irregular dolomitic layers, thin sandy laminae, and slaty or phyllitic partings characterize limestone and marble of lower, middle, and upper parts of the Bascom, respectively; south of West Rutland it includes some of the Chipman formation. The combined Luke Hill, Naylor Ledge, and Hastings Creek, east of Philipsburg thrust, are stratigraphically equivalent to the Bascom.
Brezee Formation (Cambrian)
Brezee Formation - Dark gray to black phyllite with beds of blue-gray marble, dark gray dolomite, sandy dolomite, and dolomitic sandstone, in upper part; beds of massive quartzite as much as 20 ft thick occur locally and in places contain pebbles of blue quartz. Phyllites are locally highly albitic.
Cheshire Quartzite (Cambrian)
Cheshire Quartzite - Very massive, white to faintly pink or buff vitreous quartzite near the top in west-central and southwestern VT; predominantly a less massive appearing mottled gray, somewhat phyllitic quartzite; dolomitic sandstone and conglomerate near the base of the formation in west-central VT apparently grades southward into the Dalton Formation. Mapping in Bristol Notch and along the Green Mountain front indicate that the Cheshire Quartzite appears to be at least 2500 ft thick, which is about 2.5 times the original estimated thickness to the north and south. Near the base, the Cheshire is a massive argillaceous feldspathic meta-sandstone, containing recrystallized quartz and K-feldspar in a muscovite and biotite matrix. These lithologies grade upward through medium to thick-bedded schistose feldspathic meta-sandstones to clean, massive 'quartzites' of the Green Mountain front. Rocks currently mapped as the eastern-most Cheshire Quartzite probably belong to the Pinnacle Formation and are in fault contact with the Cheshire (Condon, 1993).
Clarendon Springs, Ticonderoga, and Rock River Dolomites; Gorge Formation (Cambrian)
Clarendon Springs, Ticonderoga, and Rock River Dolomite; Gorge Formation - Fairly uniform, massive, smooth weathered gray dolomite characterized by numerous geodes and knots of white quartz; quartz sandstone and irregular masses of chert are near the top. Called the Ticonderoga west of Orwell and Champlain thrusts and the Rock River east of Philipsburg thrust. The Gorge is a partly conglomeratic facies on the west limb of the St. Albans synclinorium..
Cutting Dolomite, and Undifferentiated Morgan Corner and Wallace Creek Formations (Ordovician)
Cutting Dolomite, and Undifferentiated Morgan Corner and Wallace Creek Formations - Typical Cutting is a massive, gray weathered, nondescript dolomite with finely laminated calcareous sandstone at base. The combined Morgan Corner and Wallace Creek Formations, east of Philipsburg thrust, are stratigraphically equivalent to the Cutting. Cutting Formation of Cady (1945) is stratigraphically extended to include Division D, member 1 of Brainerd and Seeley, 1890, (now called Smith Basin Member), and is here renamed Cutting Hill Formation. No new type section is designated. Redefined unit includes Winchell Creek Sandstone Member, East Shoreham Member (named), and Smith Basin Member (Washington and Chisick, 1988).
Forestdale Marble (Cambrian)
Forestdale Marble - Buff to rusty-weathered white, buff, and pink and white mottled dolomite containing local interbeds of dolomitic sandstone, gray-green phyllitic quartzite, and crossbedded sandy dolomite.
Hathaway Formation (Ordovician)
Hathaway Formation - Gray to black argillite and bedded radiolarian chert, with included blocks and fragments of chert, limestone, dolomite, sandstone and graywacke.
Middlebury and Chazy Limestone; Undifferentiated Youngman and Carman Formations (Ordovician)
Middlebury and Chazy Limestone, Undifferentiated Youngman and Carman Formations - Dark blue-gray, somewhat nodular and granular limestone with buff dolomite and shaly interbeds a fraction of an inch thick and 2 to 4 inches apart. The Middlebury, which is east of Champlain and Orwell thrusts, and the Youngman, which is east of Highgate Springs thrust, are, due partly to deformation, more slaty in appearance than the Chazy, which is west of the major thrusts. The Carman is a quartz sandstone with shaly partings that underlies the Youngman. The Chazy contains 3 members.
Middlebury and Chazy Limestone, Undifferentiated Youngman and Carman Formations, Day Point Member (Ordovician)
Middlebury and Chazy Limestone, Undifferentiated Youngman and Carman Formations, Day Point Member - Calcareous quartz sandstone, and calcarenite; orange-weathered dolomitic siltstones are common in eastern areas.
Orwell Limestone, Isle la Motte and Lowville Limestones; Root Pond quartzite member (Ordovician)
Orwell Limestone, Isle la Motte and Lowville Limestones; Root Pond quartzite member - Massive quartz sandstone, near Benson and West Haven, that overlies Orwell limestone.
Parker Slate (Cambrian)
Parker Slate - Gray to black micaceous shale and slate, includes dolomite, sandstone, and quartzite lenses; chiefly on west limb of St. Albans synclinorium.
Rugg Brook Formation (Cambrian)
Rugg Brook Formation - Sandy gray dolomite, dolomite conglomerate, and interbeds of gray-weathered sandstone, in St. Albans and Middlebury synclinoria.
Saxe Brook Dolomite (Cambrian)
Saxe Brook Dolomite - Sandy gray dolomite, sandstone containing dolomitic cement, and pure dolomite; on west limb of St. Albans synclinorium.
Sweetsburg Formation, Skeels Corners Slate and Mill River Conglomerate Members Undifferentiated (Cambrian)
Sweetsburg Formation, Skeels Corners Slate and Mill River Conglomerate Members Undifferentiated - Black slate; local dolomite, sandstone, dolomite conglomerate, limestone bioherm, limestone, and calcareous shale. The Mill River is a basal limestone conglomerate.
Washington
Cambrian quartzite (Cambrian)
Gritstone with conglomerate in lower part and gray, white, and buff platy quartzite in upper part grading upward into phyllite; northern Pend Oreille County. Light-gray, platy, medium- to thick-bedded quartzite in upper part and darker impure quartzite with some interbedded argillite or phyllite in lower part; north-central Stevens County. White, gray, and reddish, medium- to thick-bedded quartzite in lower part and thin interbeds of quartzite and argillite in upper part, with very low Lower Cambrian fossils (Nevadia, Hyolthellus, and three genera of brachipods) near base of upper part; Addy district of central Stevens County. Thick argillite and thin quartzite units form an uppermost zone in southwestern Stevens County. Conspicuous phyllite units near base in north-central Lincoln County.
Cretaceous nonmarine rocks (Late Cretaceous)
Redbeds of thick-bedded sandstone, shale, and pebble conglomerate in upper Methow River area of Okanogan County.
Cretaceous sedimentary rocks, mostly marine (Late Cretaceous; possibly Eocene)
Cretaceous conglomerate, sandstone, shale, breccia, limestone, and gritstone in San Juan Islands.
Eocene volcanic rocks (Eocene )
Predominantly andesite flows and breccia; includes interbedded sedimentary rocks south of Startup in Snohomish and King Counties.
Lower Tertiary volcanic rocks, undivided (Eocene)
Predominantly andesite flows and flow breccia; includes basalt flows, minor rhyolitic rocks, and some sedimentary rocks.
Lower upper Eocene marine and nonmarine rocks (Eocene)
Predominantly massive to well-bedded tuffaceous marine siltstone with interbedded arkosic and basaltic sandstone. Includes conglomerate in King County and along north side of Olympic Peninsula. Minor lava flows and breccia in western Lewis County and eastern Grays Harbor County. Coal seams in central Lewis County and north-central Pierce County.
Mesozoic-Tertiary volcanic rocks, undivided (Oligocene to Eocene)
Altered basalt, pillow lavas, and flow breccia of inner volcanic belt of Olympic Peninsula; includes minor interbedded red limy argillite and associated manganese ore.
Mesozoic volcanic rocks, undivided (Jurassic)
Includes latite, andesite and basalt flows, tuff, and agglomerate. Interbedded sedimentary rocks in Orient area of Stevens County.
Middle and lower Eocene volcanic rocks (Eocene)
Dark-gray, course- to fine-grained, strongly chloritized basalt flows and breccia; includes pillow lava, deeply altered palagonite beds, amygdoidal and vesicular flows, and, locally, sedimentary rocks. Comprises outer volcanic belt in Olympic Peninsula, where manganese ore is associated with some submarine lavas.
Miocene marine rocks (Miocene)
Massive to thin-bedded, friable, basaltic to feldspathic sandstone, with shale, siltstone, and local pebble conglomerate interbeds.
Miocene nonmarine rocks (Late Miocene)
Poorly to moderately consolidated tuffaceous sandstone, conglomerate, siltstone, and claystone in western Washington. Chiefly clay and shale with minor sand, gravel, and diatomaceous earth near Spokane. Includes diatomite beds near Yakima and Quincy, and some marine beds in Western Washington.
Miocene-Pliocene marine rocks (Miocene-Pliocene)
Brown-gray, coarse-grained, moderately consolidated, commonly cross-bedded sandstone. Grades locally into gritstone and conglomerate lenses; includes minor shale beds; sandstone often shaly and in some areas grades into claystone.
Miocene volcanic rocks (Middle Miocene)
Dark-gray to black, dense aphanitic basalt flows; commonly columnar jointed, less commonly irregularly and platy jointed; some flows vesicular, grading to scoriaceous; includes minor pillow lava, palagonite beds, and interbedded soil profiles and sedimentary beds; contains diatomite beds locally. Maximum thickness in south-central Washington may be in excess of 10,000 feet; much thinner in western Washington, where flows are mostly associated with marine sedimentary rocks. Includes acidic and intermediate volcanic rocks in northern Cascade Mountains.
Oligocene marine rocks (Late Eocene to Late Oligocene)
Massive, tuffaceous and nontuffaceous sandstone and siltstone; locally concretionary; includes conglomerate along the north coast of Olympic Peninsula and basaltic sandstone east of Chehalis.
Oligocene-Miocene marine rocks (Oligocene)
Massive to thin-bedded, coarse-grained sandstone, conglomerate, conglomeratic sandstone, shale, and sandy shale.
Oligocene-Miocene volcanic rocks (Miocene)
Andesite flow breccia, andesite flows, and minor tuff beds; includes some basalt flows and flow breccia. Commonly more massive and less altered than similar-appearing Eocene-Oligocene volcanic rocks. Clastic flows and flows of black glass, and course to fine-grained clastic and pyroclastic rocks in the Republic and Curlew areas of Ferry County.
Oligocene nonmarine rocks (Oligocene)
Andesite conglomerate, tuff beds, and mudflow material. Includes some interbedded andesite flows in Columbia River Gorge. Lake sediments with Oligocene flora in Republic area in Ferry County. Massive tuffaceous sandstone and siltstone with beds of coal and high-alumina clay in Castle Rock-Toledo coal district in Cowlitz and Lewis Counties; include local interbedded basalt flows and some marine and late Eocene rocks.
Oligocene volcanic rocks (Oligocene)
Andesite and rhyodacite flows, tuff, and tuffaceous sandstones of northern Lincoln County and southwestern Stevens County.
Pliocene marine rocks (Pliocene)
Coarse conglomerate, shale, and minor sandstone; along ocean beaches in Grays Harbor County.
Precambrian conglomerate (Late-Proterozoic)
Gray-brown, coarse, poorly sorted pebbles and cobbles of limestone, dolomite, reddish-brown quartzite, black slate or phyllite, and rarely granitic rocks in a gray sandy phyllite matrix; northeastern Pend Oreille County and southwestern Stevens County. Rocks become finer grained and more schistose and the unit becomes thicker toward the southwest, where there is included an isolated subunit which may be a tillite, consisting of cobbles, boulders, and blocks of argillite and carbonate rocks in a fine silty matrix.
Precambrian (?) phyllite (Cambrian-Precambrian boundary)
Mostly phyllite with interbedded carbonate rocks, quartzite, and gritstone; some tufflike beds and conglomerate at the base. Rocks confined to northeastern Pend Oreille County and central Stevens County.
Precambrian rocks, undivided (Proterozoic)
Predominantly phyllite with some schist, limestone, dolomite, quartzite, and volcanic rocks; northeastern Pend Oreille County. Mainly quartzite sandstone in upper part, dark-gray argillite with sandstone and limestone in middle part, and sandstone with argillite in lower part; southeastern Pend Oreille County. Banded slate with quartzite and dolomite; southwestern Stevens County. Quartzite, siliceous argillite, and argilliceous quartzite grading into argillite and quartz-mica schists form south ot north; southeastern Stevens County. Quartzite, argillite, quartz-feldspar gneiss, and other metamorphic rocks in northeastern Whitman and southeastern Spokane Counties are partly if not all extenstions of the Belt strata.
Pre-upper Eocene rocks (Eocene (Olympic Peninsula); Cretaceous(?) (Yakima County))
Argillite and graywacke between inner and outer volcanic belts in Olympic Peninsula. Sheared carbonaceous argillite, argillite, graywacke, and minor conglomerate lenses and altered lava flows in western Yakima County.
Tertiary-Cretaceous basic intrusive rocks (Cretaceous-Jurassic)
Diorite and gabbro in western Snohomish County.
Tertiary marine and nonmarine rocks (Eocene)
Predominantly light-gray to olive-gray, fine to course-grained, thick-bedded sandstone with laminae to thick beds of medium dark gray siltstone, in northern Olympic Peninsula. Probably late Eocene to Miocene.
Tertiary nonmarine rocks, undivided (Tertiary; mostly Eocene)
Sandstone, shale, conglomerate, agglomerate, and tuff; includes some lava flows. Massive conglomerate, sandstone, siltstone, and ferruginous shale in northwestern Whatcom County.
Triassic sedimentary rocks, undivided (Triassic with Permian where impossible to differentiate)
Predominantly limestone, marble, and dolomite near Riverside in Okanogan County. Conglomerate, shale, graywacke, gritstone, and limestone on San Juan Island. Siltstone with greenstone locally on Orcas Island. Graywacke conglomerate, cherty greenstone, and limestone in northern Ferry County.
Upper Cretaceous-lower Tertiary volcanic rocks (Late Cretaceous)
Dark-gray to green andesite tuff, breccia, and flows in Methow River area of Okanogan County.
Upper Eocene volcanic rocks (Late-Middle Eocene)
Rhyolite flows and some interbedded tuff beds in Cle Elum area, Kittitas County.
Upper Eocene volcanic rocks (Late Eocene)
Andesite and basalt flows and associated breccia in central Lewis County. Pyroclastic rocks, mudflows, flow breccia, and volcanic-rich sedimentary rocks in King and Pierce Counties.
Upper Eocene volcanic rocks (Late Eocene)
Predominantly andesite flows and breccia; includes some basalt flows. Contains basaltic conglomerate, pyroclastic rocks, tuff beds, and sandstone in Chehalis-Centralia coal district, Lewis County.
Upper Eocene volcanic rocks (Late Eocene to Oligocene)
Predominantly basalt flows and flow breccia; includes some pyroclastic and andesite rocks. Chiefly in western Washington.
Upper Jurassic-Lower Cretaceous sedimentary and volcanic rocks (Late Cretaceous-Jurassic)
Sedimentary and volcanic rocks, undivided. Graywacke, argillite, siltstone, slate, volcanic rocks, phyllite, greenschist, and greenstone.
Upper Tertiary volcanic rocks, undivided (Miocene-Oligocene)
Mostly massive andesite flows, flow breccia, and pyroclastic material; includes some basalt flows and sedimentary rocks.
Upper upper Eocene nonmarine and marine rocks (Middle Eocene)
Massive to thin-bedded, feldspathic to arkosic sandstone, siltstone, shale, and carbonaceous shale; becomes mostly marine in the western foothills of Cascade Mountains where coal beds are abundant. Basaltic sandstone and siltstone in northern Olympic Peninsula.
Wisconsin
Ancell Group (Ordovician)
Ancell Group - Orthoquartzitic sandstone with minor limestone, shale and conglomerate; includes Glenwood and St. Peter Formations
Baraga Group; Tyler Formation (Early Proterozoic)
Baraga Group; Tyler Formation - Light- to dark-gray, feldspathic, fine-grained sandstone, argillaceous siltstone, and argillite. Near base, ferruginous argillite contains beds of cherty sideritic and pyritic iron-formation
Bayfield Group; Devil's Island Sandstone (Middle Proterozoic)
Bayfield Group; Devil's Island Sandstone - Well-sorted quartzose sandstone
Cambrian, undivided (Cambrian)
Cambrian, undivided - Sandstone with some dolomite and shale, undivided; includes Trempealeau, Tunnel City, and Elk Mound Formations
Copper Harbor Conglomerate (Middle Proterozoic)
Copper Harbor Conglomerate - Red lithic conglomerate and sandstone; mafic to felsic volcanic flows similar to those of the unnamed formation (unit Yu) are interlayered with the sedimentary rocks.
Jacobsville Sandstone (Middle Proterozoic)
Jacobsville Sandstone - Red, brown, and white quartzose sandstone, and minor siltstone, shale and conglomerate
Oronto Group; Nonesuch Shale (Middle Proterozoic)
Oronto Group; Nonesuch Shale- Gray, green, and brown lithic siltstone, shale, and sandstone. Copper sulfides and native copper occur locally near base
Prairie du Chien Group (Ordovician)
Prairie du Chien Group - Dolomite with some sandstone and shale; includes Shakopee and Oneota Formations
West Virginia
Allegheny Formation (Pennsylvanian)
Allegheny Formation - cyclic sequences of sandstone, siltstone, shale, limestone, and coal. Includes the Freeport, Kittanning and Clarion coals, also, the Princess coals of Kentucky . Extends from the top of the Upper Freeport coal to the top of the Homewood Sandstone.
Antietam Formation (Cambrian)
Antietam Formation (Chilhowee Group) - gray to white quartzite, sandstone and quartz-schist; thick-bedded, and resistant; contains Scolithus.
Bluefield Formation (Mississippian)
Bluefield Formation (part of Mauch Chunk Group) - red and green shale and sandstone, with a few thin limestone lenses, such as the Reynolds.
Bluestone and Princeton Formations (Mississippian)
Bluestone and Princeton Formations (part of Mauch Chunk Group) - the Bluestone Formation is mostly red, green, and medium-gray shale and sandstone; Princeton Sandstone is underneath.
Brallier Formation (Devonian)
Brallier Formation - predominantly olive-gray to dark, thickly laminated marine shale, with considerable siltstone and thin sandstone lenses; mainly nonfossiliferous.
Brallier Formation and Harrell Shale, undivided (Devonian)
Brallier Formation and Harrell Shale, undivided - Brallier Formation : predominantly olive-gray to dark, thickly laminated marine shale, with considerable siltstone and thin sandstone lenses; mainly nonfossiliferous. Harrell Shale: dark gray to black thinly laminated to fissile shale. Calcareous shale and limestone lenses near the base (Tully).
Chemung Group (Devonian)
Chemung Group - gray to brown siltstone and sandstone with shale and conglomeratic interbeds; mainly marine and sparingly fossiliferous; boundaries gradational. Can be divided into the Voreknobs and Scherr Formations along the Allegheny Front. Parkhead Sandstone Member near base.
Conemaugh Group (Pennsylvanian)
Conemaugh Group - cyclic sequences of red and gray shale, siltstone, and sandstone, with thin limestones and coals. Mostly non-marine. May be divided into Casselman and Glenshaw Formations. Extends from the base of the Pittsburgh coal to the top of the Upper Freeport coal. Includes the Elk Lick, Bakerstown, and Mahoning coals, and the Ames and Brush Creek Limestones.
Dunkard Group (Permian/Pennsylvanian)
Dunkard Group - non-marine cyclic sequences of sandstone, siltstone, red and gray shale, limestone, and coal. Contains the Greene, Washington and Waynesburg Formations. Extends from the top of the exposed bed rock section to the top of the Waynesburg coal. Includes the Washington coals and limestones. Palynological evidence favors a Pennsylvanian age, at least for the lower portion.
Greenbrier Group (Mississippian)
Greenbrier Group - marine limestone and marine and non-marine red and gray shale, and minor sandstone beds in numerous formational units.
Hampshire Formation (Devonian)
Hampshire Formation - non-marine shales and fine micaceous sandstones, mostly red to brownish-gray, including siltstone, sandstone and conglomerate. Generally distinguishable from the underlying Chemung by non-marine character and red color.
Helderberg Group (Devonian)
Helderberg Group - mostly cherty limestone, with some sandstone and shale. Contains several named stratigraphic units, including the Keyser Formation, which is partly Silurian and includes the Clifton Forge Sandstone and Big Mountain Shale Members.
Hinton Formation (Mississippian)
Hinton Formation (part of Mauch Chunk Group) - red, green, and medium-gray shale and sandstone, with a few thin limestone beds, including the Avis.
Juniata and Oswego Formations (Ordovician)
Juniata and Oswego Formations - the Juniata is a thin-bedded, blocky, red sandstone and shale. In places it is underlain by the thick-bedded, gray Oswego Sandstone.
Kanawha Formation (Pennsylvanian)
Kanawha Formation (part of Pottsville Group) - sandstone (approx 50%), shale, siltstone, and coal. Contains several marine zones. Becomes more shaly westward in the subsurface. Extends from the top of the Homewood Sandstone to the top of the Upper Nuttall Sandstone. Includes the Stockton (Mercer), Coalburg, Winifrede, Chilton, Williamson, Cedar Grove, Alma, Peerless, Campbell Creek, Powellton, Eagle, Gilbert, and Douglas coals.
Maccrady Formation (Mississippian)
Maccrady Formation - red shale and mudrock, red and green sandstone, and minor limestone. Present only from Pendleton County southward. Contains rock salt and gypsum in southwestern Virginia.
Maccrady Formation and Pocono Group, undivided (Mississippian)
Maccrady Formation and Pocono Group, undivided - Maccrady Formation: red shale and mudrock, red and green sandstone, and minor limestone. Present only from Pendleton County southward. Contains rock salt and gypsum in southwestern Virginia. Pocono Group: predominantly hard gray massive sandstones, with some shale. In the Eastern Panhandle, has been divided into the Hedges, Purslane, and Rockwell Formations.
Mahantango Formation (Devonian)
Mahantango Formation (part of Millboro Shale) - thickly laminated marine shale, siltstone, very fine sandstone, and some limestone, with an occasional coral reef or biostrome. Contains the Clearville and Chaneysville Siltstone Members of Pennsylvania.
Martinsburg Formation (Ordovician)
Martinsburg Formation - predominantly gray to dark shale, yellowish in the upper portion. Contains scattered thin limestone and sandstone interbeds, particularly in the lower portion. The upper portion constitutes the Reedsville Shale.
Mauch Chunk Group (Mississippian)
Mauch Chunk Group - red, green, and medium-gray shale and sandstone, with a few thin limestones.
McKenzie Formation and Clinton Group (Silurian)
McKenzie Formation and Clinton Group - includes the McKenzie Formation, consisting of shale with thin limestone lenses; the dark Rochester Shale; the white Keefer Sandstone; and the Rose Hill predominantly red shale, with thin sandstone interbeds, some of which are called "iron sandstones" from their reddish-brown color and hematite content.
McKenzie Formation, Clinton Group and Tuscarora Sandstone, undivided (Silurian)
McKenzie Formation, Clinton Group and Tuscarora Sandstone, undivided - McKenzie Formation and Clinton Group: includes the McKenzie Formation, consisting of shale with thin limestone lenses; the dark Rochester Shale; the white Keefer Sandstone; and the Rose Hill predominantly red shale, with thin sandstone interbeds, some of which are called "iron sandstones" from their reddish-brown color and hematite content. Tuscarora Sandstone: medium- to thick-bedded, white to gray or pinkish sandstone, fine to coarse, quartzitic, ridge-forming. Equivalent to the Clinch Sandstone of Tennessee.
Monongahela Group (Pennsylvanian)
Monongahela Group - non-marine cyclic sequences of sandstone, siltstone, red and gray shale, limestone, and coal. Contains the Uniontown and Pittsburgh Formations. Extends from the top of the Waynesburg coal to the base of the Pittsburgh coal. Includes the Waynesburg, Uniontown, Sewickley, Redstone and Pittsburgh coals. Thickness is 170 feet in Mineral and Grant Counties.
New River Formation (Pennsylvanian)
New River Formation (part of Pottsville Group) - predominantly sandstone, with some shale, siltstone, and coal. Grades to nearly all sandstone in the subsurface. Extends from the top of the Upper Nuttall Sandstone to the top of the Flattop Mountain Sandstone. Includes the Iaeger, Sewell, Welch, Raleigh, Beckley, Fire Creek, and Pocahontas Nos. 8 and 9 coals.
Oriskany Sandstone and Helderberg Group, undivided (Devonian)
Oriskany Sandstone and Helderberg Group, undivided - Oriskany Sandstone: sometimes designated Ridgeley in eastern West Virginia. White to brown coarse- to fine-grained, partly calcareous sandstone, locally pebbly or conglomeratic, and ridge-forming. May be white, nearly pure silica, and a source of glass sand, as at Berkeley Springs, Morgan County. Helderburg Group: mostly cherty limestone, with some sandstone and shale. Contains several named stratigraphic units, including the Keyser Formation, which is partly Silurian and includes the Clifton Forge Sandstone and Big Mountain Shale Members.
Oriskany Sandstone and Huntersville Chert (Devonian)
Oriskany Sandstone and Huntersville Chert - Oriskany Sandstone: sometimes designated Ridgeley in eastern West Virginia. White to brown coarse- to fine-grained, partly calcareous sandstone, locally pebbly or conglomeratic, and ridge-forming. May be white, nearly pure silica, and a source of glass sand, as at Berkeley Springs, Morgan County. Huntersville Chert (part of Onesquethaw ("Onondaga") Group): ranges from a nearly pure slightly calcitic or dolomitic chert to an inter-tonguing of such chert and the Needmore Shale. Grades westward in the subsurface to a limestone, commonly considered as "Onondaga". Contains the "glauconitic" Bobs Ridge Sandstone Member. Not mappable at scale of this map. Included with Do.
Pocahontas Formation (Pennsylvanian)
Pocahontas Formation (part of Pottsville Group) - sandstone, approx. 50%, with some shale, siltstone, and coal. Extends from the top of the Flattop Mountain Sandstone to the top of the Mississippian. Includes from bottom upward Pocahontas coals Nos. 1 through 7.
Pocono Group (Mississippian)
Pocono Group - predominantly hard gray massive sandstones, with some shale. In the Eastern Panhandle, has been divided into the Hedges, Purslane, and Rockwell Formations.
Pottsville Group (Pennsylvanian)
Pottsville Group - includes the Kanawha, New River, and Pocahontas Formations. Predominantly sandstones, some of which are conglomeratic, with thin shales and coals. Undivided in northern West Virginia.
Tonoloway, Wills Creek, and Williamsport Formations (Silurian)
Tonoloway, Wills Creek, and Williamsport Formations - includes the thin-bedded platy argillaceous limestones of the Tonoloway, the thin-bedded shale with fossiliferous limestones of the Wills Creek, the Bloomsburg red clastic facies, and the greenish-brown to white Williamsport Sandstone. The Wills Creek contains anhydrite and rock salt, the latter supplying brine from deep wells along the Ohio River.
Tuscarora Sandstone (Silurian)
Tuscarora Sandstone - medium- to thick-bedded, white to gray or pinkish sandstone, fine to coarse, quartzitic, ridge-forming. Equivalent to the Clinch Sandstone of Tennessee.
Waynesboro Formation (Cambrian)
Waynesboro Formation - variegated shale and sandstone, commonly red or brown. Middle zone contains much dolomite and limestone. Contains the Olenellus fauna of Early Cambrian age, although its upper portion may be of Middle Cambrian age.
Weverton-Loudoun Formation (Cambrian)
Weverton-Loudoun Formation (Chilhowee Group) - tough quartzitic sandstones, conglomerates, and shale.
Wyoming
Adaville Formation (Phanerozoic | Mesozoic | Cretaceous-Late)
ADAVILLE FORMATION--Gray sandstone, siltstone, and carbonaceous claystone; conglomeratic in upper part; coal-bearing in lower part.
Aspen Shale (Phanerozoic | Mesozoic | Cretaceous-Early)
ASPEN SHALE--Light- to dark-gray siliceous tuffaceous shale and siltstone, thin bentonite beds, and quartzitic sandstone.
Bacon Ridge Sandstone (Phanerozoic | Mesozoic | Cretaceous-Late)
BACON RIDGE SANDSTONE--Gray to tan marine sandstone and thick coal beds; gold-bearing quartzite conglomerate in lower part.
Baxter Shale (Phanerozoic | Mesozoic | Cretaceous-Late)
BAXTER SHALE--Gray to black soft sandy shale and shaly sandstone.
Bear River Formation (Phanerozoic | Mesozoic | Cretaceous-Early)
BEAR RIVER FORMATION--Black shale, fine-grained brown sandstone, thin limestone, and bentonite beds.
Bighorn Dolomite, Gallatin Limestone, and Gros Ventre Formation (TB), Bighorn Dolomite, Snowy Range Formation, Pilgrim Limestone, Park Shale, Meagher Limestone, Wolsey Shale, and Flathead Sandstone (Y), Bighorn Dolomite, Gallatin Limestone, Gros Ventre Formation, and Flathead Sandstone (N), or Whitewood Dolomite, and WInnipeg and Deadwood Formations (NE) (Phanerozoic | Paleozoic | Cambrian-Middle Cambrian-Furongian(?) Ordovician-Early(?) Ordovician-Middle(?) Ordovician-Late)
BIGHORN DOLOMITE, GALLATIN LIMESTONE, and GROS VENTRE FORMATION. BIGHORN DOLOMITE (Thrust Belt)--Gray massive cliff-forming siliceous dolomite and locally dolomitic limestone. GALLATIN LIMESTONE--Gray and tan limestone. GROS VENTRE FORMATION--Greenish-gray micaceous shale. BIGHORN DOLOMITE, SNOWY RANGE FORMATION, PILGRIM LIMESTONE, PARK SHALE, MEAGHER LIMESTONE, WOLSEY SHALE, AND FLATHEAD SANDSTONE (Yellowstone). BIGHORN DOLOMITE--Light-gray massive siliceous dolomite. SNOWY RANGE FORMATION (Gallatin Group)--Medium-gray limestone and underlying greenish-gray shale. PILGRIM LIMESTONE (Gallatin Group)--Blue-gray and yellow mottled hard limestone. PARK SHALE--Green micaceous soft shale. Upper part may be Late Cambrian. MEAGHER LIMESTONE--Blue-gray and yellow mottled hard limestone. WOLSEY SHALE--Green micaceous soft shale. FLATHEAD SANDSTONE--Dull-red quartzitic sandstone. BIGHORN DOLOMITE, GALLATIN LIMESTONE, GROS VENTRE FORMATION, AND FLATHEAD SANDSTONE (north Wyoming). BIGHORN DOLOMITE--Gray massive cliff-forming siliceous dolomite and locally dolomitic limestone. GALLATIN LIMESTONE--Blue-gray and yellow mottled hard dense limestone. GROS VENTRE FORMATION--Soft green micaceous shale (Upper and Middle Cambrian Park Shale Member), underlain by blue-gray and yellow mottled hard dense limestone (Middle Cambrian Death Canyon Limestone Member), and soft green micaceous shale (Middle Cambrian Wolsey Shale Member). FLATHEAD SANDSTONE--Dull-red quartzitic sandstone. WHITEWOOD DOLOMITE, AND WINNIPEG AND DEADWOOD FORMATIONS (northeast Wyoming). WHITEWOOD DOLOMITE--Buff massive fossiliferous dolomite. WINNIPEG FORMATION--Pink to yellow siltstone and shale. DEADWOOD FORMATION--Red and brown quartzitic sandstone.
Casper and Fountain Formations (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle Pennsylvanian-Late Permian)
CASPER AND FOUNTAIN FORMATIONS. CASPER FORMATION--Gray, tan, and red thick-bedded sandstone underlain by interbedded sandstone and pink and gray limestone. May include some Devonian(?) sandstone along east flank of Laramie Mountains. FOUNTAIN FORMATION--Arkose and red sandstone.
Casper Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle Pennsylvanian-Late Permian)
CASPER FORMATION--Gray, tan, and red thick-bedded sandstone underlain by interbedded sandstone and pink and gray limestone. May include some Devonian(?) sandstone along east flank of Laramie Mountains.
Chugwater and Goose Egg Formations (Phanerozoic | Paleozoic Mesozoic | Permian Triassic-Early(?) Triassic-Middle(?) Triassic-Late)
CHUGWATER AND GOOSE EGG FORMATIONS (north Wyoming). CHUGWATER FORMATION--Red siltstone and shale. Alcova Limestone Member in upper middle part in north Wyoming. Thin gypsum partings near base in north and northeast Wyoming. GOOSE EGG FORMATION--Red sandstone and siltstone, white gypsum, halite, and purple to white dolomite and limestone; CHUGWATER FORMATION OR GROUP (south Wyoming)--Red shale and siltstone containing thin gypsum partings near base. Group includes Popo Agie Formation (red shale and red, yellow, and purple siltstone; lenses of lime-pellet conglomerate), Crow Mountain Sandstone (red and gray, thick bedded), Alcova Limestone, and Red Peak Formation (red siltstone and shale). Chugwater Formation includes as members all the units listed above. Includes overlying Jelm Formation in Shirley and Seminoe Mountains and at northern end of Laramie Basin. JELM FORMATION--Red sandstone. GOOSE EGG FORMATION--Red sandstone and siltstone, white gypsum, halite, and purple to white dolomite and limestone.
Chugwater Formation (N, NE), or Chugwater Formation or Group (S) (Phanerozoic | Mesozoic | Triassic-Early Triassic-Middle(?) Triassic-Late)
CHUGWATER FORMATION (north, northeast Wyoming)--Red siltstone and shale. Alcova Limestone Member in upper middle part in north Wyoming. Thin gypsum partings near base in north and northeast Wyoming. [None mapped in the NE]; CHUGWATER FORMATION OR GROUP (south Wyomingt)--Red shale and siltstone containing thin gypsum partings near base. Group includes Popo Agie Formation (red shale and red, yellow, and purple siltstone; lenses of lime-pellet conglomerate), Crow Mountain Sandstone (red and gray, thick bedded), Alcova Limestone, and Red Peak Formation (red siltstone and shale). Chugwater Formation includes as members all the units listed above. Includes overlying Jelm Formation in Shirley and Seminoe Mountains and at northern end of Laramie Basin. JELM FORMATION--Red sandstone.
Cloverly and Morrison Formations (N,S) or Cloverly Formation, Inyan Kara Group, and Morrison Formation (Phanerozoic | Mesozoic | Jurassic-Late Cretaceous-Early)
CLOVERLY FORMATION and MORRISON FORMATION. CLOVERLY FORMATION--Rusty sandstone at top, underlain by brightly variegated bentonitic claystone; chert-pebble conglomerate locally at base. MORRISON FORMATION--Dully variegated claystone, nodular limestone, and gray silty sandstone. In southern Yellowstone and Jackson Hole areas the presence of Morrison is questionable; CLOVERLY FORMATION (Hartville uplift) or INYAN KARA GROUP (Black Hills) and MORRISON FORMATION. CLOVERLY FORMATION--Rusty to light-gray sandstone containing lenticular chert-pebble conglomerate interbedded with variegated bentonitic claystone. INYAN KARA GROUP--Rusty to light-gray sandstone containing lenticular chert-pebble conglomerate interbedded with variegated bentonitic claystone. Includes Fall River and Lakota Formations. MORRISON FORMATION, in northeast Wyoming, dully variegated siliceous claystone, nodular white limestone, and gray silty sandstone.
Cody Shale (Phanerozoic | Mesozoic | Cretaceous-Late (78-83 Ma))
CODY SHALE (AGE 78 TO 83 Ma) northern Yellowstone area--Gray to brown shale and siltstone; north and south Wyoming--Dull-gray shale, gray siltstone, and fine-grained gray sandstone.
Cody Shale and Frontier Formation (N, S) (Phanerozoic | Mesozoic | Cretaceous-Late (78-83 Ma))
CODY SHALE AND FRONTIER FORMATION north and south Wyoming. CODY SHALE (AGE 78 TO 83 Ma) (Kc2)--Dull-gray shale, gray siltstone, and fine-grained gray sandstone. FRONTIER FORMATION (Kf2)--Gray sandstone and sandy shale.
Colter Formation (Phanerozoic | Cenozoic | Tertiary | Miocene)
COLTER FORMATION--Dull-green and gray tuff, volcanic conglomerate, and sandstone.
Evanston Formation (Phanerozoic | Mesozoic Cenozoic | Cretaceous-Late Tertiary | Paleocene)
EVANSTON FORMATION--Gray siltstone, sparse red sandstone, and lignite beds.
Everts Formation, Eagle Sandstone, and Telegraph Creek Formation (Phanerozoic | Mesozoic | Cretaceous-Late)
EVERTS FORMATION, EAGLE SANDSTONE, AND TELEGRAPH CREEK FORMATION--Massive to thin-bedded sandstone, mudstone, and shale.
Ferris Formation (Phanerozoic | Mesozoic Cenozoic | Cretaceous-Late Tertiary | Paleocene)
FERRIS FORMATION--Brown and gray sandstone and shale; sparse carbonaceous shale and coal beds; thin lenses of pebble conglomerate.
Fort Union Formation (Phanerozoic | Cenozoic | Tertiary | Paleocene )
FORT UNION FORMATION Tongue River Member--Thick beds of yellow sandstone interbedded with gray and black shale and many coal beds.
Fort Union Formation (Phanerozoic | Cenozoic | Tertiary | Paleocene )
FORT UNION FORMATION northwest, southwest, and central Wyoming--Brown to gray sandstone, gray to black shale, and thin coal beds; east Wyoming--Light-colored massive sandstone, drab shale, and thick coal beds.
Fort Union Formation (Phanerozoic | Cenozoic | Tertiary | Paleocene )
FORT UNION FORMATION Tullock Member--Soft gray sandstone, gray and brown carbonaceous shale, and thin coal beds.
Fort Union Formation (Phanerozoic | Cenozoic | Tertiary | Paleocene )
FORT UNION FORMATION Lebo Member--Dark-gray clay shale and concretionary sandstone.
Fox Hills Sandstone (Phanerozoic | Mesozoic | Cretaceous-Late)
FOX HILLS SANDSTONE--Light-colored sandstone and gray sandy shale containing marine fossils.
Fox Hills Sandstone and Bearpaw Shale (Phanerozoic | Mesozoic | Cretaceous-Late)
FOX HILLS SANDSTONE AND BEARPAW SHALE. FOX HILLS SANDSTONE (Kfh)--Light-colored sandstone and gray sandy shale containing marine fossils. BEARPAW SHALE--Dark-greenish-gray shale containing thin gray sandstone partings.
Fox Hills Sandstone and Lewis Shale (Phanerozoic | Mesozoic | Cretaceous-Late)
FOX HILLS SANDSTONE AND LEWIS SHALE. FOX HILLS SANDSTONE (Kfh)--Light-colored sandstone and gray sandy shale containing marine fossils. LEWIS SHALE (AGE ABOUT 68 Ma) (Kle)--Gray marine shale containing many gray and brown lenticular concretion-rich sandstone beds.
Frontier Formation (Phanerozoic | Mesozoic | Cretaceous-Late)
FRONTIER FORMATION in thrust belt--White to brown sandstone and dark-gray shale; oyster coquina in upper part; coal and lignite in lower part; in north and south Wyoming--Gray sandstone and sandy shale.
Frontier Formation and Mowry and Thermopolis Shales (Phanerozoic | Mesozoic | Cretaceous-Early Cretaceous-Middle(?) Cretaceous-Late)
FRONTIER FORMATION (Kf) AND MOWRY (Kmr) AND THERMOPOLIS SHALES. FRONTIER FORMATION--Gray sandstone and sandy shale. In Northern Yellowstone area, Yellowish- to medium-gray sandstone; tuffaceous and carbonaceous in lower part. MOWRY SHALE (AGE 94 TO 98 Ma)--Silvery-gray hard siliceous shale containing abundant fish scales and bentonite beds. THERMOPOLIS SHALE--Black soft fissile shale; Muddy Sandstone Member at top.
Gallatin Limestone, Gros Ventre Formation and equivalents, and Flathead Sandstone (N) or Cambrian Rocks (S) (Phanerozoic | Paleozoic | Cambrian-Middle Cambrian-Furongian)
GALLATIN LIMESTONE, GROS VENTRE FORMATION and equivalents, and FLATHEAD SANDSTONE (north Wyoming). GALLATIN LIMESTONE--Blue-gray and yellow mottled hard dense limestone. GROS VENTRE FORMATION--Soft green micaceous shale (Upper and Middle Cambrian Park Shale Member), underlain by blue-gray and yellow mottled hard dense limestone (Middle Cambrian Death Canyon Limestone Member), and soft green micaceous shale (Middle Cambrian Wolsey Shale Member). FLATHEAD SANDSTONE--Dull-red quartzitic sandstone. CAMBRIAN ROCKS (south Wyoming). South flank of Granite Mountains--Blue-gray and yellow mottled hard dense limestone interbedded with soft green micaceous shale; dull-red quartzitic sandstone at base. On and south of Rawlins uplift--Glauconitic quartzitic sandstone.
Gannett Group (Phanerozoic | Mesozoic | Cretaceous-Early)
GANNETT GROUP--Red sandy mudstone, sandstone, and chert-pebble conglomerate; thin limestone and dark-gray shale in upper part, more conglomeratic in lower part. Includes Smoot Formation (red mudstone and siltstone), Draney Limestone, Bechler Conglomerate, Peterson Limestone, and Ephraim Conglomerate. Upper Jurassic fossils have been reported from the Ephraim.
Green River and Wasatch Formations (Phanerozoic | Cenozoic | Tertiary | Eocene)
GREEN RIVER AND WASATCH FORMATIONS -- in Thrust Belt: GREEN RIVER FORMATION--Buff laminated marlstone and limestone, brown oil shale, and siltstone. Includes Angelo and Fossil Butte Members. WASATCH FORMATION--Variegated mudstone and sandstone. Includes Tunp and Bullpen Members, other tongues and unnamed members, and main body (variegated red to gray, brown, and gray mudstone and sandstone; conglomerate lenses); in southwest Wyoming -- GREEN RIVER FORMATION--Oil shale, light-colored tuffaceous marlstone, and sandstone. WASATCH FORMATION--Drab to variegated claystone and siltstone, carbonaceous shale and coal, buff sandstone, arkose, and conglomerate. In northwestern part of Green River Basin is thick arkosic light-yellowish-tan sandstone intertonguing with pale-green to gray claystone and shale.
Guernsey Formation (Phanerozoic | Paleozoic | Devonian-Late Carboniferous Mississippian-Early)
GUERNSEY FORMATION--Blue-gray massive cherty limestone and dolomite. Locally includes unnamed dolomite and sandstone of Devonian and Cambrian(?) age.
Gypsum Spring Formation and Nugget Sandstone (Phanerozoic | Mesozoic | Triassic-Early Triassic-Middle(?) Triassic-Late(?) Jurassic-Early(?) Jurassic-Middle(?) Jurassic-Late)
GYPSUM SPRING FORMATION AND NUGGET SANDSTONE. GYPSUM SPRING FORMATION--Interbedded red shale, dolomite, and gypsum. In north Wyoming wedges out south in T. 39 N. NUGGET SANDSTONE--gray to dull-red, crossbedded quartz sandstone.
Harebell Formation (Phanerozoic | Mesozoic | Cretaceous-Late)
HAREBELL FORMATION--Gold-bearing quartzite conglomerate, olive-drab sandstone, and green claystone.
Hartville Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early Pennsylvanian-Middle(?) Pennsylvanian-Late(?) Permian)
HARTVILLE FORMATION--Red and white sandstone underlain by gray dolomite and limestone, red shale, and red and gray sandstone. Lowermost unit may be Late Mississippian in age.
Lance Formation (Phanerozoic | Mesozoic | Cretaceous-Late)
LANCE FORMATION north Wyoming--Thick-bedded buff sandstone and drab to green shale; thin conglomerate lenses; south and northeast Wyoming--Brown and gray sandstone and shale; thin coal and carbonaceous shale beds.
Landslide Creek Formation (Phanerozoic | Mesozoic | Cretaceous-Late)
LANDSLIDE CREEK FORMATION--Greenish-gray bentonitic tuffaceous sandstone and conglomerate.
Lewis Shale (Phanerozoic | Mesozoic | Cretaceous-Late)
LEWIS SHALE (AGE ABOUT 68 Ma)--Gray marine shale containing many gray and brown lenticular concretion-rich sandstone beds.
Lower Miocene Rocks (Phanerozoic | Cenozoic | Tertiary | Miocene-Early)
LOWER MIOCENE ROCKS--Northwest Wyoming (Bighorn Mountains): Gray soft poorly bedded to massive sandstone; Central Wyoming: Tuffaceous sandstone, siltstone, and white marl.
Madison Limestone, Darby Formation, Bighorn Dolomite, Gallatin Limestone, Gros Ventre Formation, and Flathead Sandstone (N), Madison Limestone and Cambrian rocks (S), Minnekahta Limestone, Opeche Shale, Minnelusa Formation, Pahasapa and Englewood Limestones, Whitewood Dolomite, Winnipeg and Deadwood Formations (NE), or Paleozoic, undifferentiated (Phanerozoic | Paleozoic | Cambrian Ordovician(?) Silurian(?) Devonian(?) Carboniferous(?) Permian)
MADISON LIMESTONE, DARBY FORMATION, BIGHORN DOLOMITE, GALLATIN LIMESTONE, GROS VENTRE FORMATION, AND FLATHEAD SANDSTONE (north Wyoming). MADISON LIMESTONE OR GROUP--Group includes Mission Canyon Limestone (blue-gray massive limestone and dolomite), underlain by Lodgepole Limestone (gray cherty limestone and dolomite). DARBY FORMATION--Yellow and greenish-gray shale and dolomitic siltstone underlain by fetid brown dolomite and limestone. BIGHORN DOLOMITE--Gray massive cliff-forming siliceous dolomite and locally dolomitic limestone. GALLATIN LIMESTONE--Blue-gray and yellow mottled hard dense limestone. GROS VENTRE FORMATION--Soft green micaceous shale (Upper and Middle Cambrian Park Shale Member), underlain by blue-gray and yellow mottled hard dense limestone (Middle Cambrian Death Canyon Limestone Member), and soft green micaceous shale (Middle Cambrian Wolsey Shale Member). FLATHEAD SANDSTONE--Dull-red quartzitic sandstone. MADISON LIMESTONE AND CAMBRIAN ROCKS (south Wyoming). MADISON LIMESTONE--Includes Mission Canyon Limestone (blue-gray massive limestone and dolomite), underlain by Lodgepole Limestone (gray cherty limestone and dolomite). CAMBRIAN ROCKS--On south flank of Granite Mountains, blue-gray and yellow mottled hard dense limestone interbedded with soft green micaceous shale; dull-red quartzitic sandstone at bae. On and south of Rawlins uplift, glauconitic quartzitic sandstone. MINNEKAHTA LIMESTONE, OPECHE SHALE, MINNELUSA FORMATION, PAHASAPA AND ENGLEWOOD LIMESTONES, WHITEWOOD DOLOMITE, AND WINNIPEG AND DEADWOOD FORMATIONS--Various combinations (northeast Wyoming). MINNEKAHTA LIMESTONE--Gray slabby hard limestone. Locally is a member of the Goose Egg Formation. OPECHE SHALE--Red soft sandy shale. Locally is a member of the Goose Egg Formation. MINNELUSA FORMATION--Buff and red limy sandstone; some thin limestone beds, solution breccias, and gypsum. PAHASAPA LIMESTONE--Gray massive dolomititc limestone. ENGLEWOOD LIMESTONE--Pink slabby dolomitic limestone. WHITEWOOD DOLOMITE--Buff massive fossiliferous dolomite. WINNIPEG FORMATION--Pink to yellow siltstone and shale. DEADWOOD FORMATION--Red and brown quartzitic sandstone. PALEOZOIC ROCKS, undifferentiated (Thrust Belt).
Madison Limestone, Darby or Three Forks, Jefferson, and Beartooth Butte Formations, and Bighorn Dolomite (Phanerozoic | Paleozoic | Ordovician-Middle Ordovician-Late(?) Silurian(?) Devonian(?) Carboniferous Mississippian-Early(?) Mississippian-Middle(?) Mississippian-Late)
MADISON LIMESTONE, DARBY or THREE FORKS, JEFFERSON, AND BEARTOOTH BUTTE FORMATION. MADISON GROUP--Group includes Mission Canyon Limestone (blue-gray massive limestone and dolomite), underlain by Lodgepole Limestone (gray cherty limestone and dolomite). DARBY FORMATION--Yellow and greenish-gray shale and dolomitic siltstone underlain by fetid brown dolomite and limestone. THREE FORKS FORMATION--Yellow and greenish-gray shale and dolomitic siltstone. JEFFERSON FORMATION--Fetid brown dolomite and limestone. BEARTOOTH BUTTE FORMATION--Red sandstone, limy siltstone, and limestone. Occurs only in the Beartooth Mountains.
Medicine Bow Formation (Phanerozoic | Mesozoic | Cretaceous-Late)
MEDICINE BOW FORMATION--Brown and gray sandstone and shale; thin coal and carbonaceous shale beds.
Meeteetse Formation (Phanerozoic | Mesozoic | Cretaceous-Late)
MEETEETSE FORMATION (AGE ABOUT 73 Ma)--Chalky-white to gray sandstone, yellow, green, and dark-gray bentonitic claystone, white tuff, and thin coal beds.
Mesaverde Formation (N) or Mesaverde Group (S) (Phanerozoic | Mesozoic | Cretaceous-Late)
MESAVERDE FORMATION (north Wyoming)--Light-colored massive to thin-bedded sandstone, gray sandy shale, and coal beds. In Jackson Hole locally contains gold-bearing quartzite conglomerate. North of North Fork Powder River east of the Bighorn Mountains, consists solely of the Parkman Sandstone Member; MESAVERDE GROUP (SOUTH WYOMING). Includes Almond Formation, Ericson Sandstone, Rock Springs and Blair Formations in Rock Springs uplift; Almond Formation (white and brown soft sandstone, gray sandy shale, coal and carbonaceous shale), Pine Ridge Sandstone (light-gray sandstone and thin coal beds), and Allen Ridge (gray sandstone, shale, and thin coal beds) and Haystack Mountains (gray marine sandstone and shale) Formations in Rawlins uplift; Pine Ridge Sandstone (light-gray sandstone and thin coal beds) and Rock River Formation (soft sandstone and sandy shale) in Laramie Basin.
Mesaverde Group, Almond Formation (Phanerozoic | Mesozoic | Cretaceous-Late)
MESAVERDE GROUP (SOUTH WYOMING). Rock Springs uplift. Almond Formation--White and brown soft sandstone, gray sandy shale, coal, and carbonaceous shale.
Mesaverde Group, Blair Formation. (Phanerozoic | Mesozoic | Cretaceous-Late)
MESAVERDE GROUP (SOUTH WYOMING). Rock Springs uplift. Blair Formation--Drab-yellow and brown sandstone and sandy shale.
Mesaverde Group, Ericson Sandstone (Phanerozoic | Mesozoic | Cretaceous-Late)
MESAVERDE GROUP (SOUTH WYOMING). Rock Springs uplift. Ericson Sandstone--White massive sandstone; lenticular chert-grit conglomerate in upper part.
Mesaverde Group, Rock Springs Formation (Phanerozoic | Mesozoic | Cretaceous-Late)
MESAVERDE GROUP (SOUTH WYOMING). Rock Springs uplift. Rock Springs Formation--White to brown sandstone, shale, and claystone; numerous coal beds.
Minnelusa Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early Pennsylvanian-Middle(?) Pennsylvanian-Late(?) Permian)
MINNELUSA FORMATION--Buff and red limy sandstone; some thin limestone beds, solution breccias, and gypsum.
Miocene Rocks (Phanerozoic | Cenozoic | Tertiary | Miocene)
MIOCENE ROCKS--Southwest Wyoming: Southern Rock Springs uplift--Pale-green to tan tuffaceous sandstone and claystone of Miocene(?) age. Conglomerate of uncertain correlation locally at base. Saratoga Valley and west and southwest to Colorado--White massive soft tuffaceous sandstone and lesser amounts of white marl; lower part conglomeratic. Underlies North Park Formation in Saratoga Valley. To the west and southwest is called Browns Park Formation. Rawlins area--White massive soft tuffaceous sandstone; Central Wyoming: White soft tuffaceous sandstone. Locally derived conglomerate in upper and lower parts of sequence; in places lower conglomeratic sequence may be of Oligocene age. In Granite Mountains K/Ar age of tuff in lower part of sandstone sequence about 17 Ma and fission-track age of lower conglomerate about 24 Ma.
Mowry and Thermopolis Shales (Phanerozoic | Mesozoic | Cretaceous-Early)
MOWRY (Kmr) AND THERMOPOLIS SHALES. MOWRY SHALE (AGE 94 TO 98 Ma)--Silvery-gray hard siliceous shale containing abundant fish scales and bentonite beds. THERMOPOLIS SHALE--Black soft fissile shale; Muddy Sandstone Member at top.
Newcastle Sandstone and Skull Creek Shale (Phanerozoic | Mesozoic | Cretaceous-Early)
NEWCASTLE SANDSTONE AND SKULL CREEK SHALE. NEWCASTLE SANDSTONE--Gray sandstone and sandy shale containing some bentonite and coal. SKULL CREEK SHALE--Black soft fissile shale.
Niobrara and Frontier Formations, and Mowry and Thermopolis Shales (Phanerozoic | Mesozoic | Cretaceous-Early Cretaceous-Middle(?) Cretaceous-Late)
NIOBRARA (Kn) AND FRONTIER (Kf) FORMATIONS, AND MOWRY (Kmr) AND THERMOPOLIS SHALES. NIOBRARA FORMATION (AGE ABOUT 83 Ma)--Light-colored limestone and gray to yellow speckled limy shale. FRONTIER FORMATION--Gray sandstone and sandy shale. MOWRY SHALE (AGE 94 TO 98 Ma)--Silvery-gray hard siliceous shale containing abundant fish scales and bentonite beds. THERMOPOLIS SHALE--Black soft fissile shale; Muddy Sandstone Member at top.
Nugget Sandstone (Phanerozoic | Mesozoic | Triassic(?) Jurassic(?) )
NUGGET SANDSTONE--Thrust Belt: Buff to pink crossbedded well-sized and well-sorted quartz sandstone and quartzite; locally has oil and copper-silver-zinc mineralization. North Wyoming: Gray to dull-red, crossbedded quartz sandstone.
Nugget Sandstone, Ankareh Formation, Thaynes Limestone, Woodside Shale, and Dinwoody Formation (TB), or Nugget Sandstone and Chugwater and Dinwoody Formations (N) (Phanerozoic | Mesozoic | Triassic-Early Triassic-Middle(?) Triassic-Late(?) Triassic(?) Jurassic(?))
NUGGET SANDSTONE, ANKAREH FORMATION, THAYNES LIMESTONE, WOODSIDE SHALE, and DINWOODY FORMATION (Thrust Belt). NUGGET SANDSTONE--Buff to pink crossbedded well-sized and well-sorted quartz sandstone and quartzite; locally has oil and copper-silver-zinc mineralization. ANKAREH FORMATION--Red and maroon shale and purple limestone. THAYNES LIMESTONE--Gray limestone and limy siltstone. WOODSIDE SHALE--Red siltstone and shale. DINWOODY FORMATION--Gray to olive-drab dolomitic siltstone. NUGGET SANDSTONE AND CHUGWATER AND DINWOODY FORMATIONS (north Wyoming). NUGGET SANDSTONE--Gray to dull-red, crossbedded quartz sandstone. CHUGWATER FORMATION--Red siltstone and shale. Alcova Limestone Member in upper middle part in north Wyoming. Thin gypsum partings near base in north and northeast Wyoming. DINWOODY FORMATION--Olive-drab hard dolomitic thin-bedded siltstone.
Phosphoria Formation (Phanerozoic | Paleozoic | Permian)
PHOSPHORIA FORMATION AND RELATED ROCKS--Thrust Belt: Upper part is dark- to light-gray chert and shale with black shale and phosphorite at top; lower part is black shale, phosphorite, and cherty dolomite; north Wyoming: Brown sandstone and dolomite, cherty phosphatic and glauconitic dolomite, phosphatic sandstone and dolomite, and greenish-gray to black shale. Intertonguing equivalents of parts of Phosphoria are Park City Formation (primarily cherty dolomite, limestone, and phosphatic gray shale) and Shedhorn Sandstone.
Phosphoria, Wells, and Amsden Formations (TB), Phosphoria Formation and related rocks, Quadrant Sandstone, and Amsden Formation (Y), or Phosphoria Formation and related rocks, Tensleep Sandstone, and Amsden Formation (N) (Phanerozoic | Paleozoic | Carboniferous Mississippian-Late Pennsylvanian(?) Permian)
PHOSPHORIA, WELLS, AND AMSDEN FORMATIONS (Thrust Belt). PHOSPHORIA FORMATION--Upper part is dark- to light-gray chert and shale with black shale and phosphorite at top; lower part is black shale, phosphorite, and cherty dolomite. WELLS FORMATION--Gray limestone interbedded with yellow limy sandstone. AMSDEN FORMATION--Red and gray cherty limestone and shale, sandstone, and conglomerate. PHOSPHORIA FORMATION AND RELATED ROCKS, QUADRANT SANDSTONE, AND AMSDEN FORMATION (Yellowstone). PHOSPHORIA FORMATION AND RELATED ROCKS--Brown sandstone and dolomite, cherty phosphatic and glauconitic dolomite, phosphatic sandstone and dolomite, and greenish-gray to black shale. Intertonguing equivalent is Shedhorn Sandstone. QUADRANT SANDSTONE--Light-gray sandstone. AMSDEN FORMATION--Red and green dolomitic shale, siltstone, and sandstone. PHOSPHORIA FORMATION AND RELATED ROCKS, TENSLEEP SANDSTONE, AND AMSDEN FORMATION (north Wyoming). PHOSPHORIA FORMATION AND RELATED ROCKS--Brown sandstone and dolomite, cherty phosphatic and glauconitic dolomite, phosphatic sandstone and dolomite, and greenish-gray to black shale. Intertonguing equivalents of parts of Phosphoria are Park City Formation (primarlily cherty dolomite, limestone, and phosphatic gray shale) and Shedhorn Sandstone. TENSLEEP SANDSTONE--White to gray sandstone containing thin limestone and dolomite beds. Permian fossils have been found in the topmost beds of the Tensleep at some localities in Washakie Range, Owl Creek Mountains, and southern Bighorn Mountains. AMSDEN FORMATION--Red and green shale and dolomite; at base is brown sandstone.
Pinyon Conglomerate (Phanerozoic | Mesozoic Cenozoic | Cretaceous-Late Tertiary | Paleocene)
PINYON CONGLOMERATE--Brown gold-bearing quartzite conglomerate interbedded with brown and gray sandstone. Age of basal part about 67 Ma in northeastern Jackson Hole; farther south entire sequence is Paleocene.
Sage Junction, Quealy, Cokeville, THomas Fork, and Smiths Formations (Phanerozoic | Mesozoic | Cretaceous-Early)
SAGE JUNCTION, QUEALY, COKEVILLE, THOMAS FORK, AND SMITHS FORMATIONS. SAGE JUNCTION FORMATION--Gray and tan siltstone and sandstone. QUEALY FORMATION--Variegated mudstone and tan sandstone. COKEVILLE FORMATION--Tan sandstone, claystone, limestone, bentonite, and coal. THOMAS FORK FORMATION--Variegated mudstone and gray sandstone. SMITHS FORMATION--Ferruginous black shale and tan to brown sandstone.
Sandstone and Conglomerate (Phanerozoic | Cenozoic | Tertiary | Oligocene Miocene)
SANDSTONE AND CONGLOMERATE--Gray hard coarse-grained sandstone and conglomerate.
Sedimentary Rocks (Phanerozoic | Mesozoic Cenozoic | Cretaceous-Late Tertiary | Paleocene)
SEDIMENTARY ROCKS--Northern part of Wind River Basin. White-weathering oil-stained sandstone and brown carbonaceous shale.
Sohare Formation (Phanerozoic | Mesozoic | Cretaceous-Late)
SOHARE FORMATION--Lenticular gray and brown sandstone and shale; thin coal beds.
Sohare Formation and Bacon Ridge Sandstone (Phanerozoic | Mesozoic | Cretaceous-Late)
SOHARE FORMATION AND BACON RIDGE SANDSTONE. SOHARE FORMATION (Kso)--Lenticular gray and brown sandstone and shale; thin coal beds. BACON RIDGE SANDSTONE (Kb)--Gray to tan marine sandstone and thick coal beds; gold-bearing quartzite conglomerate in lower part.
Steele Shale (Phanerozoic | Mesozoic | Cretaceous-Late)
STEELE SHALE (AGE ABOUT 78 TO 82 Ma)--Gray soft marine shale containing numerous bentonite beds and thin lenticular sandstone.
Steele Shale and Niobrara Formations (Phanerozoic | Mesozoic | Cretaceous-Late)
STEELE SHALE (Ks) AND NIOBRARA FORMATIONS (Kn). STEELE SHALE (AGE ABOUT 78 TO 82 Ma)--Gray soft marine shale containing numerous bentonite beds and thin lenticular sandstone. NIOBRARA FORMATION (AGE ABOUT 83 Ma)--Light-colored limestone and gray to yellow speckled limy shale.
Stump Formation, Preuss Sandstone or Redbeds, and Twin Creek Limestone (Phanerozoic | Mesozoic | Jurassic-Middle Jurassic-Late)
STUMP FORMATION, PREUSS SANDSTONE or REDBEDS, and TWIN CREEK LIMESTONE. STUMP FORMATION--Glauconitic siltstone, sandstone, and limestone. PREUSS SANDSTONE OR REDBEDS--Purple, maroon, and reddish-gray sandy siltstone and claystone; contains salt and gypsum in thick beds in some subsurface sections. TWIN CREEK LIMESTONE--Greenish-gray shaly limestone and limy siltstone. Includes Gypsum Spring Member.
Sundance and Gypsum Spring Formations (Phanerozoic | Mesozoic | Jurassic-Middle Jurassic-Late)
SUNDANCE (Js) AND GYPSUM SPRING FORMATIONS. SUNDANCE FORMATION--Greenish-gray glauconitic sandstone and shale, underlain by red and gray nonglauconitic sandstone and shale. GYPSUM SPRING FORMATION--Interbedded red shale, dolomite, and gypsum. In north Wyoming wedges out south in T. 39 N.
Sundance and Gypsum Spring Formations and Nugget Sandstone (Phanerozoic | Mesozoic | Triassic(?) Jurassic(?) Jurassic-Early(?) Jurassic-Middle(?) Jurassic-Late)
SUNDANCE AND GYPSUM SPRING FORMATIONS AND NUGGET SANDSTONE. SUNDANCE FORMATION--Greenish-gray glauconitic sandstone and shale, underlain by red and gray nonglauconitic sandstone and shale. GYPSUM SPRING FORMATION--Interbedded red shale, dolomite, and gypsum. In north Wyoming wedges out south in T. 39 N. NUGGET SANDSTONE--gray to dull-red, crossbedded quartz sandstone.
Sundance Formation (Phanerozoic | Mesozoic | Jurassic-Middle Jurassic-Late)
SUNDANCE FORMATION--Greenish-gray glauconitic sandstone and shale, underlain by red and gray nonglauconitic sandstone and shale.
Tensleep Sandstone and Amsden Formation (Phanerozoic | Paleozoic | Carboniferous Mississippian-Late Pennsylvanian(?) Permian)
TENSLEEP SANDSTONE AND AMSDEN FORMATION. North Wyoming: TENSLEEP SANDSTONE--White to gray sandstone containing thin limestone and dolomite beds. Permian fossils have been found in the topmost beds of the Tensleep at some localities in Washakie Range, Owl Creek Mountains, and southern Bighorn Mountains. AMSDEN FORMATION--Red and green shale and dolomite; at base is brown sandstone. South Wyoming: TENSLEEP SANDSTONE AND AMSDEN FORMATION. TENSLEEP SANDSTONE--White to gray sandstone containing thin limestone and dolomite beds. AMSDEN FORMATION--Red and green shale and dolomite; at base is persistent red to brown sandstone.
Three Forks and Jefferson Formations and Bighorn Dolomite (Y) or Three Forks, Jefferson, and Beartooth Butte Formations and Bighorn Dolomite (N) (Phanerozoic | Paleozoic | Ordovician-Middle Ordovician-Late(?) Silurian(?) Devonian-Early(?) Devonian-Middle(?) Devonian-Late)
THREE FORKS, JEFFERSON, AND BEARTOOTH BUTTE FORMATIONS AND BIGHORN DOLOMITE (Yellowstone). THREE FORKS FORMATION--Pink, yellow, and green dolomitic siltstone and shale. JEFFERSON FORMATION--Massive siliceous dolomite. BEARTOOTH BUTTE FORMATION--Red sandstone, limy siltstone, and limestone. Occurs only in the Beartooth Mountains. BIGHORN DOLOMITE--Light-gray massive siliceous dolomite. THREE FORKS, JEFFERSON, AND BEARTOOTH BUTTE FORMATIONS AND BIGHORN DOLOMITE (north Wyoming). THREE FORKS FORMATION--Yellow and greenish-gray shale and dolomitic siltstone. JEFFERSON FORMATION--Fetid brown dolomite and limestone. BEARTOOTH BUTTE FORMATION--Red sandstone, limy siltstone, and limestone. Occurs only in the Beartooth Mountains. BIGHORN DOLOMITE--Gray massive cliff-forming siliceous dolomite and locally dolomitic limestone.
Upper Miocene Rocks (Phanerozoic | Cenozoic | Tertiary | Miocene-Late)
UPPER MIOCENE ROCKS--Southwest Wyoming: South end of Wind River Range--Siliceous, arkosic, and locally radioactive sandstone, claystone, and conglomerate. Fission-track age about 27 Ma. Recent work suggests that part of these deposits may be of Eocene age. Pliocene and Miocene (as originally defined 2) South Pass Formation. Saratoga Valley--White to greenish-gray tuffaceous sandstone, siltstone, and claystone; locally conglomeratic. North Park Formation; Central Wyoming: Arkosic sandstone, conglomerate, and siltstone; some light-colored tuffaceous radioactive claystone and white cherty limestone. North of Sweetwater River in Granite Mountains--Light-colored tuffaceous radioactive claystone, siltstone, sandstone, and arkose. Moonstone Formation; East Wyoming: Light-colored tuffaceous claystone, sandstone, and conglomerate. Ogallala Formation in Denver Basin.
Wagon Bed Formation (Phanerozoic | Cenozoic | Tertiary | Eocene (45-49 Ma))
WAGON BED FORMATION (AGE ABOUT 45 TO 49 Ma)--Southwest and central Wyoming--Green and gray tuffaceous claystone, sandstone, and conglomerate; some uranium-phosphate marlstone and variegated bentonitic claystone. Locally contains oil shale between Wind River and Bighorn Basins; Central Wyoming (west side of Laramie Mountains)--Dull-green siliceous bentonitic claystone and tuff; giant granite boulder conglomerate in tuffaceous matrix.
Wasatch Formation (Phanerozoic | Cenozoic | Tertiary | Eocene)
WASATCH FORMATION -- in Thrust belt: Main body--Variegated red to gray, brown, and gray mudstone and sandstone; conglomeratic lenses; in southwest Wyoming--Drab to variegated claystone and siltstone, carbonaceous shale and coal, buff sandstone, arkose, and conglomerate. In northwestern part of Green River Basin is thick arkosic light-yellowish-tan sandstone intertonguing with pale-green to gray claystone and shale; in east Wyoming--Drab sandstone and drab to variegated claystone; numerous coal beds in lower part.
Wasatch Formation (SW) (Phanerozoic | Cenozoic | Tertiary | Eocene)
WASATCH FORMATION Niland Tongue--Brown sandstone, carbonaceous shale, and coal.
Wasatch Formation (SW) (Phanerozoic | Cenozoic | Tertiary | Paleocene Eocene)
WASATCH FORMATION Main body--Drab sandstone, drab to variegated claystone and siltstone; locally derived conglomerate around basin margins. Lower part is Paleocene.
Wasatch Formation (SW) (Phanerozoic | Cenozoic | Tertiary | Paleocene Eocene)
WASATCH FORMATION La Barge and Chappo Members--Red, gray, and brown mudstone and conglomerate and yellow sandstone. La Barge Member tongues out to north at about T. 35 N. Lower part of Chappo is Paleocene.
Wayan and Smiths Formations (Phanerozoic | Mesozoic | Cretaceous-Early)
WAYAN AND SMITHS FORMATIONS. WAYAN FORMATION--Variegated mudstone, siltstone, and sandstone. SMITHS FORMATION--Ferruginous black shale and tan to brown sandstone.
Wells and Amsden Formations (TB), or Casper Formation and Madison Limestone (N, S) (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early Pennsylvanian-Middle(?) Pennsylvanian-Late(?) Permian)
WELLS AND AMSDEN FORMATIONS (Thrust Belt). WELLS FORMATION--Gray limestone interbedded with yellow limy sandstone. AMSDEN FORMATION--Red and gray cherty limestone and shale, sandstone, and conglomerate. CASPER FORMATION AND MADISON LIMESTONE (north, south Wyoming). CASPER FORMATION--Gray, tan, and red thick-bedded sandstone underlain by interbedded sandstone and pink and gray limestone. May include some Devonian(?) sandstone along east flank of Laramie Mountains. MADISON LIMESTONE--Includes Mission Canyon Limestone (blue-gray massive limestone and dolomite), underlain by Lodgepole Limestone (gray cherty limestone and dolomite).
Wind River Formation (Phanerozoic | Cenozoic | Tertiary | Eocene)
WIND RIVER FORMATION Northwest Wyoming (Jackson Hole)--Variegated red and white claystone and siltstone; largely nontuffaceous except near the top; lenticular coal unit in middle. At base locally includes equivalent of Indian Meadows Formation; Central Wyoming--Variegated claystone and sandstone; lenticular conglomerate. Age of tuff at top 49 Ma.

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