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Geologic units containing carbonate

Alabama

Selma Group; Demopolis Chalk (Cretaceous)

Demopolis Chalk - (Selma Group), Light-gray to medium-light-gray compact, brittle chalk overlain by abundantly fossiliferous chalky marl, very clayey chalk, and calcareous clay (Bluffport Marl Member). In south-central Montgomery County the Demopolis is split into two eastward extending tongues by a westward-extending tongue of the Cusseta Sand Member of the Ripley Formation. The lower tongue is pale-olive to yellowish-gray silty to finely sand, micaceous, fossiliferous chalk that eastward becomes more sandy and merges with the Cusseta in central Bullock County. The upper tongue is yellowish-gray clayey, very finely sandy, micaceous chalk that merges with the Ripley in southeastern Montgomery County.

Selma Group; Mooreville Chalk (Cretaceous)

Mooreville Chalk - (Selma Group), Yellowish-gray to olive-gray compact fossiliferous clayey chalk and chalky marl. The unconformable contact at the base is characterized by a bed of glauconitic, chalky sand containing phosphate pellets and molds of fossils. The Arcola Limestone Member at the top consists of two to four beds of light-gray brittle, dense, fossiliferous limestone separated by beds of light-gray to pale-olive calcareous clay.

Selma Group; Prairie Bluff Chalk (Upper Cretaceous)

Prairie Bluff Chalk - (Selma Group), Very light-gray to light-bluish-gray firm sandy, fossiliferous brittle chalk and grayish-black silty sandy calcareous glauconitic, fossiliferous clay; semi-indurated beds of sandy, clayey limestone are present in some exposures. Abscent locally in parts of Marengo, Dallas and Wilcox Counties where overlapped by the Clayton Formation or eroded. The Prairie Bluff thins eastward from southwestern Lowndes County to northern Pike County where it interfingers with the Providence Sand.

Talladega Group; Lay Dam Formation, unnamed diamictite facies (Silurian?-Devonian)

Talladega Group; Lay Dam Formation, unnamed diamictite facies - Unnamed diamictite facies of Lay Day Formation in Coosa and Chilton Counties consists of cobbles and boulders of carbonate, pelitic rocks, quartzite, chert, felsic plutonic rocks, and gneiss in a metagraywacke matrix.

Arkansas

Cretaceous rocks (Phanerozoic | Mesozoic | Cretaceous)

Cretaceous rocks

Kiamichi Formation and Goodland Limestone (Phanerozoic | Mesozoic | Cretaceous-Early)

Kiamichi Formation and Goodland Limestone

Nacatoch Sand (Phanerozoic | Mesozoic | Cretaceous-Late)

Nacatoch Sand

Georgia

Claiborne undifferentiated (Eocene)

Claiborne undifferentiated, up-dip equivalent of Lisbon and Tallahatta Formations

Iowa

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

Idaho

Arenite, carbonate, conglomerate, and shale; Late Proterozoic rifted continental margin; southeastern Idaho (Late Proterozoic)

Uppermost Younger Precambrian massive quartzite with carbonate beds of central and southeastern Idaho; overlies (Z1s).

Quartzite, argillite, carbonate, meta-conglomerate, siltite, intermediate volcanic rock; Late Proterozoic rifted continental margin; southeastern Idaho (Late Proterozoic)

Younger Precambrian detrital units of central and southeastern Idaho; subdivisions are (Z2s and Z1s).

Kansas

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

Mississippi

Demopolis chalk (Upper Cretaceous)

Demopolis chalk - (Selma group), Chalk and marly chalk containing fewer impurities than underlying and overlying formations.

Mooreville chalk (Upper Cretaceous)

Mooreville chalk - (Selma group), Marly chalk and calcareous clay.

Prairie Bluff chalk and Owl Creek formation (Upper Cretaceous)

Prairie Bluff chalk and Owl Creek formation - (Selma group), Prairie Bluff chalk, compact brittle chalk, sandy chalk, and calcareous clay; at base contains many phosphatic molds of fossils; in Ponotoc and Union Counties merges northward into Owl Creek formation, tough blue glauconitic sandy clay.

Ripley formation (Upper Cretaceous)

Ripley formation - (Selma group), gray to greenish-gray fine glauconitic sand, clay, and sandy limestone; south of Oktibbeha County is very sandy micaceous chalk.

Montana

Alluvium (Phanerozoic | Cenozoic | Quaternary)

Alluvium: mainly valley fill consisting of silt, sand, and gravel; includes some terrace deposits and glacial drift of Pleistocene age in some areas; locally includes hot spring tufa. The older part of the alluvium, where present, is probably of Pliocene age.

Altyn limestone (Proterozoic | Mesoproterozoic)

Altyn limestone: dominantly dolomite and magnesian limestone that weathers to a distinctive yellowish brown; some feldspathic quartzite and conglomerate. Correlation with the Ravalli group is provisional.

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.

Devonian, undifferentiated (Phanerozoic | Paleozoic | Devonian)

Devonian, undifferentiated: comprises Three Forks formation consisting of carbonaceous and calcareous shale with some sandstone and limestone, Jefferson limestone, and unnamed units of Devonian age.

Empire shale (Proterozoic | Mesoproterozoic)

Empire shale: green dense, laminated shale with some red beds. Distinguished only in general vicinity of Helena.

Helena limestone (Proterozoic | Mesoproterozoic)

Helena limestone: gray, unevenly laminated limestone, argillaceous and dolomitic; weathers light brown or yellow. Segregation structures and stromatolites are common. Distinguished only in general vicinity of Helena.

Mississippian, undifferentiated (Phanerozoic | Paleozoic | Carboniferous Mississippian)

Mississippian, undifferentiated: sandstone, shale, and limestone, in part dolomitic, with chert nodules, some quartzite; includes Big Snowy group in central part of State, Madison group in central and southwestern parts; and Hannan and Brazer limestones in the northwestern part; may include small amounts of Pennsylvanian rocks in areas where stratigraphic studies are incomplete.

Missoula group (Proterozoic | Mesoproterozoic)

Missoula group: chiefly red, maroon, or purple argillite; sandy or quartzitic argillite, and generally impure quartzite and limestone. The larger limestone masses are similar to the Siyeh limestone of the Piegan group. The Missoula group includes numerous named formations, most of which cannot be traced with confidence far from their type localities. Among these are the Marsh shale in the Helena region, the Striped Peak and Libby formations in northwestern Montana, five near Missoula, and others in and south of Glacier National Park.

Missoula group (Proterozoic | Mesoproterozoic)

Missoula group: chiefly red, maroon, or purple argillite; sandy or quartzitic argillite, and generally impure quartzite and limestone. The larger limestone masses are similar to the Siyeh limestone of the Piegan group. The Missoula group includes numerous named formations, most of which cannot be traced with confidence far from their type localities. Among these are the Marsh shale in the Helena region, the Striped Peak and Libby formations in northwestern Montana, five near Missoula, and others in and south of Glacier National Park.

Newland limestone (Proterozoic | Mesoproterozoic)

Newland limestone: dark bluish-gray argillaceous, dolomitic limestone with some argillite, locally schistose; segregation structures not conspicuous. In central and western Montana the Newland and Wallace formations have been treated as essentially synonymous terms by some authors.

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.

Permian, undifferentiated (Phanerozoic | Paleozoic | Permian)

Permian, undifferentiated: chert, sandstone, limestone, quartzite, and shale with rock phosphate mostly at base; mainly Phosphoria formation

Permian, undifferentiated (Phanerozoic | Paleozoic | Permian)

Permian, undifferentiated: chert, sandstone, limestone, quartzite, and shale with rock phosphate mostly at base; mainly Phosphoria formation

Piegan group (Proterozoic | Mesoproterozoic)

Piegan group: most of the Piegan group is subdivided into formations that are in part equivalent to each other. Where correlations are relatively doubtful the group designation is retained. Carbonate-bearing rocks predominate in the group, but the proportions and character of the impurities in these rocks and the relations to non-carbonate-bearing rocks vary from place to place.

Piegan group (Proterozoic | Mesoproterozoic)

Piegan group: most of the Piegan group is subdivided into formations that are in part equivalent to each other. Where correlations are relatively doubtful the group designation is retained. Carbonate-bearing rocks predominate in the group, but the proportions and character of the impurities in these rocks and the relations to non-carbonate-bearing rocks vary from place to place.

Prichard formation (Proterozoic | Mesoproterozoic)

Prichard formation: dark-gray, generally argillaceous rocks, locally sandy or quartzitic; locally metamorphosed to schist.

Siyeh limestone (Proterozoic | Mesoproterozoic)

Siyeh limestone: crystalline limestone of varying impurity; mostly thick bedded or massive, but with thin wavy banding on fresh fractures within the beds; dusky blue or greenish where fresh, weathering orange and brownish; "molar tooth", similar structures, and stromatolites are common.

Tertiary sedimentary rocks, undifferentiated (Phanerozoic | Cenozoic | Tertiary)

Tertiary sedimentary rocks, undifferentiated: clastic deposits in western Montana, mostly in valleys, and in most places not divided into formations; mostly poorly consolidated gravel, sand, silt, and clay; includes some tuffaceous material and locally lenses of lignite and bentonite; a little hot spring tufa; and in areas not yet mapped in detail, lava may be included. These rocks were in part laid down in lakes but a large part was formed in streams and alluvial fans. These rocks are Tertiary in age and as now mapped may even include some beds of Cretaceous age. Some late Tertiary terrace deposits may be included.

Wallace formation (Proterozoic | Mesoproterozoic)

Wallace formation: A heterogeneous unit that includes dark-gray argillite, arenaceous and argillaceous limestone, in part dolomitic, and gray limy quartzite, with shale and sandstone in large areas. The argillaceous and sandy or quartzitic rocks are commonly slightly calcareous. The dominantly carbonate-rich rocks contain "molar tooth" or segregation structures. Commonly characterized by thin laminae. Locally red rocks near the top may represent a transition into the Missoula group.

North Carolina

Belgrade Formation, Undivided (Tertiary)

Belgrade Formation, Undivided - Pollocksville Member: oyster-shell mounds in tan to orange sand matrix, indurated locally. Haywood Landing Member: fossiliferous clayey sand, gray to brown. Members grade into each other laterally.

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.

Nebraska

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.

New Mexico

Capitan Formation (Phanerozoic | Paleozoic | Permian)

Capitan Formation; Upper Guadalupian age limestone (reef facies)

Carlile Shale (Phanerozoic | Mesozoic | Cretaceous)

Carlile Shale; limited to northeastern area; Turonian-Coniacian

Cretaceous rocks, undivided (Phanerozoic | Mesozoic | Cretaceous)

Cretaceous rocks, undivided

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

Grayburg and Queen Fromations (Phanerozoic | Paleozoic | Permian)

Grayburg and Queen Formations; sandstone, gypsum, anhydrite, dolomite, and red mudstone; Guadalupian

Missippian through Cambrian rocks, undivided (Phanerozoic | Paleozoic | Cambrian Ordovician(?) Silurian(?) Devonian(?) Carboniferous Mississippian)

Mississippian through Cambrian rocks, undivided; includes Lake Valley Limestone; Mississippian; Devonian rocks, undivided; El Paso Formation and Montoya Group (or Formation); Ordovician; and Bliss Sandstone; Cambrian and Ordovician

Mississippian and Devonain rocks, undivided (Phanerozoic | Paleozoic | Devonian Carboniferous Mississippian)

Mississippian and Devonian rocks, undivided; includes the Lake Valley Limestone, Caballero, Las Cruces, Rancheria, and Helms Formations and Escabrosa Group; Mississippian; the Onate, Sly Gap, Contadero Formations, and Percha Shale of south-central New Mexico, and Canutillo Formation of Northern Franklin Mountains and Bishops Cap area; Devonian

Ogallala Formation (Phanerozoic | Cenozoic | Tertiary)

Ogallala Formation, alluvial and eolian deposits, and petrocalcic soils of the southern High Plains; Lower Pliocene to middle Miocene (locally includes unit Qoa)

Pennsylvanian rocks, undivided (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian)

Pennsylvanian rocks, undivided; in Sangre de Cristo Mountains may include Sandia Formation, Madera Limestone, La Pasada, Alamitos, and Flechado Formations; elsewhere may include Bar-B, Nakaye, Red House, Oswaldo, and Syrena Formations

Permain and Pennsylvanian rocks, undivided (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian Permian)

Permian and Pennsylvanian rocks, undivided; includes Horquilla Limestone, Earp Formation, Epitaph and Scherrer Formations, and Concha Limestone

Rustler Formation (Phanerozoic | Paleozoic | Permian)

Rustler Formation; siltstone, gypsum, sandstone, and dolomite; Upper Permian

San Andres Formation (Phanerozoic | Paleozoic | Permian)

San Andres Formation; limestone and dolomite with minor shale; Guadalupian in south, in part Leonardian to north

San Andres Limestone and Glorieta Sandstone (Phanerozoic | Paleozoic | Permian)

San Andres Limestone and Glorieta Sandstone; Guadalupian and Leonardian

Santa Fe Group (Phanerozoic | Cenozoic | Tertiary Quaternary)

Santa Fe Group, undivided. Basin fill of Rio Grande rift region; middle Pleistocene to uppermost Oligocene

Yates and Tansill Formations (Phanerozoic | Paleozoic | Permian)

Yates and Tansill Formations; sandstone, siltstone, limestone, dolomite, and anhydrite; Guadalupian

Yeso, Glorieta, and San Andres Formations, undivided (Phanerozoic | Paleozoic | Permian)

Yeso, Glorieta and San Andres Formations, undivided

Nevada

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

New York

Cambrian thru Middle Ordovician carbonate rock (Cambrian - Middle Ordovician)

Cambrian thru Middle Ordovician (Barneveld) carbonate rock - occuring as slivers caught along thrusts of later allochthones, or carbonate blocks in Taconic Melange. Also mapped as horses along normal faults.

Cambrian thru Middle Ordovician carbonate rock (Cambrian - Middle Ordovician)

Cambrian thru Middle Ordovician (Barneveld) carbonate rock - occuring as slivers caught along thrusts of later allochthones, or carbonate blocks in Taconic Melange.

Cambrian thru Middle Ordovician carbonate rock (Cambrian - Middle Ordovician)

Cambrian thru Middle Ordovician (Barneveld) carbonate rock - occuring as slivers caught along thrusts of later allochthones, or carbonate blocks in Taconic Melange. Also mapped as horses along normal faults.

Oklahoma

Brownstown Marl (Phanerozoic | Mesozoic | Cretaceous-Late )

McALESTER TEXARKANA- Marl and clay, gray, calcareous, micaceous, sandy and fine-grained sand, with some interbedded chalky limestones; same as upper Austin Chalk of Texas; thickness, about 100 feet.

Grayson Marl and Bennington Limestone (Phanerozoic | Mesozoic | Cretaceous-Early )

ARDMORE-SHERMAN- "Grayson Marl," marl, olive-gray, weakly indurated; thickness, about 25 feet. "Bennington Limestone" at base is moderately indurated, medium bedded; thickness, about 10 feet. McALESTER TEXARKANA- "Grayson Marl," olive-gray, weakly indurated; with Texigryphaea roemeri;" thickness, about 25 feet. "Bennington Limestone" at base, limestone, gray to gray-brown, sandy, fossiliferous, overlapped eastward by Woodbine; thickness, 6 to 18 feet.

Hunton Group (Phanerozoic | Paleozoic | Silurian Devonian-Early)

ARDMORE-SHERMAN- Marlstone, shale, and limestone, buff, ranging in age from Early Silurian to Early Devonian; thickness, 100 to 700 feet, with many unconformities Occurs in the ARBUCKLE MTNS

Keokuk and Reeds Spring Formations and St. Joe Group (Phanerozoic | Paleozoic | Carboniferous Mississippian-Early)

TULSA- "Keokuk Formation," chert and limestone. "Reeds Spring Formation," chert and limestone. "St. Joe Group," limestone and shale. FORT SMITH- Mkr "Keokuk Formation," chert; "Reeds Spring Formation," chert and limestone; and "St. Joe 'Group,'" limestone and marlstone.

Mississippian Rocks above Chattanooga Shale Undifferentiated (Phanerozoic | Paleozoic | Carboniferous Mississippian)

FORT SMITH- Mu- Undifferentiated Mississippian Rocks above Chattanooga Shale. Includes: Pitkin, Fayetteville, Hindsville, Moorefield, Keokuk and Reeds Spring Formations, and St. Joe Group.

Ozan Formation (Phanerozoic | Mesozoic | Cretaceous-Late )

McALESTER TEXARKANA- Marl and clay, light- to dark- to brownish-gray, micaceous, calcareous, sandy, fine-grained sand, with interbedded chalky limestone; glauconitic marl and sand at base; same as lower Taylor Marl of Texas; thickness, about 100 feet.

South Carolina

Huber/Lisbon/Barnwell Formations, undivided (Eocene)

Huber/Lisbon/Barnwell Formations, undivided: Poorly to well sorted sand, clay and carbonates deposited in delta-dominated fluvial- and open-marine environments. Unit is characterized by commercial kaolin bodies in older strata from westernmost South Carolina to central Georgia. Younger strata are cyclic marine deposits which deeper water facies exposed in western Georgia. Carbonate facies are locally mined in western Georgia for agricultural lime.

Texas

Goliad Formation (Phanerozoic | Cenozoic | Tertiary | Miocene)

Goliad Formation

Ogallala Formation (Phanerozoic | Cenozoic | Tertiary | Pliocene Miocene)

Ogallala Formation

Paleozoic rocks, undivided (Phanerozoic | Paleozoic)

Paleozoic rocks, undivided

Quaternary deposit, undivided (Phanerozoic | Cenozoic | Quaternary)

sand, silt, clay, and gravel. locally indurated with calcium carbonate (caliche); includes point bar, natural levee, stream channel, sand dune, terrace, alluvial fan, landslide bolson and playa deposits

upper Cretaceous rocks, undivided (Phanerozoic | Mesozoic | Cretaceous-Late)

upper Cretaceous rocks, undivided

Utah

Middle Cambrian shale and carbonate rocks in Salt Lake City-Coalville-Randolph region (Middle Cambrian)

Mississippian (2) sedimentary rocks in Logan-Huntsville Allochthon (Mississippian)

Mississippian (2) sedimentary rocks in Salt Lake City-Coalville-Randolph region (Mississippian)

Pennsylvanian and Permian sedimentary rocks in Logan-Huntsville Allochthon (Pennsylvanian to Permian)

Permian (1) sedimentary rocks in western Utah (Early Permian)

Permian (2) sedimentary rocks in Uinta Mountains-Uinta Basin region (Permian)

Permian (2) sedimentary rocks in western Utah (Permian)

Washington

Carboniferous rocks (Late Devonian to Mississippian)

Thin-bedded graywacke, shale, argillite, slate, schist, volcanic breccia, gritstone, conglomerate, and limestone on northeast shore of Orcas Island. Limestone or dolomitic limestone, apparently interbedded with limy argillite and graywacke, forms belt of small separate outcrops between Springdale and Valley in southeastern Stevens County. Late Devonian to Early Pennsylvanian in age.

Wyoming

Bridger Formation (Phanerozoic | Cenozoic | Tertiary | Eocene)

BRIDGER FORMATION--Greenish-gray, olive-drab, and white tuffaceous sandstone and claystone; lenticular marlstone and conglomerate.

Bug Formation (Phanerozoic | Cenozoic | Tertiary Quaternary | Pliocene Pleistocene)

BUG FORMATION (PLEISTOCENE OR PLIOCENE)--Lacustrine white marl, claystone, sandstone, conglomerate, and tuff; generally radioactive.

Cloverly, Morrison, Sundance, and Gypsum Spring Formations (Phanerozoic | Mesozoic | Jurassic-Middle Jurassic-Late(?) Cretaceous-Early)

CLOVERLY, MORRISON, AND SUNDANCE (Js), AND GYPSUM SPRING FORMATIONS. 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. 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.

Cloverly, Morrison, Sundance, and Gypsum Spring Formations and Nugget Sandstone (Phanerozoic | Mesozoic | Triassic(?) Jurassic(?) Cretaceous-Early)

CLOVERLY, MORRISON, AND SUNDANCE (Js), GYPSUM SPRING FORMATIONS, AND NUGGET SANDSTONE (J@n). 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. 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.

Goose Egg Formation (Phanerozoic | Paleozoic Mesozoic | Permian Triassic-Early)

GOOSE EGG FORMATION--Red sandstone and siltstone, white gypsum, halite, and purple to white dolomite and limestone.

Gypsum Spring Formation, Nugget Sandstone, and Chugwater Formation (Phanerozoic | Mesozoic | Triassic-Early Triassic-Middle(?) Triassic-Late(?) Jurassic-Early(?) Jurassic-Middle(?) Jurassic-Late)

GYPSUM SPRING FORMATION, NUGGET SANDSTONE, AND CHUGWATER FORMATION. 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. 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.

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.

Indian Meadows Formation (Phanerozoic | Cenozoic | Tertiary | Eocene)

INDIAN MEADOWS FORMATION--Red to variegated claystone, sandstone, and algal-ball(?) limestone; some beds of large Paleozoic boulders and detachment masses of Paleozoic and Mesozoic rocks.

Jelm and Chugwater Formations, Forelle Limestone, and Satanka Shale (Phanerozoic | Paleozoic Mesozoic | Permian Triassic-Early)

JELM AND CHUGWATER FORMATIONS, FORELLE LIMESTONE, AND SATANKA SHALE. CHUGWATER FORMATION OR GROUP--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. FORELLE LIMESTONE--Thin-bedded limestone. Locally is a member of the Goose Egg Formation. SATANKA SHALE--Red shale.

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.

Mesozoic and Paleozoic rocks (Phanerozoic | Paleozoic Mesozoic | Carboniferous Mississippian-Late Pennsylvanian(?) Permian(?) Triassic(?) Jurassic(?) Cretaceous-Late)

MESOZOIC AND PALEOZOIC ROCKS (north Wyoming). Shown in small areas of complex structure. East Flank of Absaroka Range--Dinwoody Formation, Phosphoria Formation and related rocks., Tensleep Sandstone, and Amsden Formation (Lower Triassic through Upper Mississippian). East flank of Bighorn Mountains--Cloverly, Morrison, Sundance, Gypsum Spring, Chugwater and Gypsum Spring Formations (Lower Cretaceous through Permian). MESOZOIC AND PALEOZOIC ROCKS (south Wyoming). Shown in small areas of complex structure. South side of Granite Mountains north of Green Mountain--Nugget Sandstone, Chugwater and Goose Egg Formations, Tensleep Sandstone, and Amsden Formation (Jurassic? through Upper Mississippian). South flank of Ferris Mountains--Nugget Sandstone and Chugwater and Goose Egg Formation (Jurassic? through Permian). Northeast flank of Seminoe Mountians--Cloverly, Morrison, Sundance, Chugwater, and Goose Egg Formations (Lower Cretaceous through Permain). West flank of Sierra Madre--Chugwater, Goose Egg, Casper, and Fountain Formations (Upper Triassic through Middle Pennsylvanian). East Flank of Laramie Mountains--Cloverly, Morrison, Sundance, Chugwater, and Goose Egg Formations, and, east of fault in T. 19 N., Casper Formation (Lower Creatceous through Middle Pennsylvanian). NUGGET SANDSTONE in south--Gray to dull-red, massive to coarsely crossbedded quartz sandstone.

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.

Salt Lake Formation (Phanerozoic | Cenozoic | Tertiary | Miocene Pliocene)

SALT LAKE FORMATION--White, gray, and green limy tuff, siltstone, sandstone, and conglomerate.

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.

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.

Wind River Formation and Indian Meadows Formations (Phanerozoic | Cenozoic | Tertiary | Eocene)

WIND RIVER AND INDIAN MEADOWS FORMATIONS. WIND RIVER FORMATION Central Wyoming (Twdr2)--Variegated claystone and sandstone; lenticular conglomerate. Age of tuff at top 49 Ma. INDIAN MEADOWS FORMATION (Twim)--Red to variegated claystone, sandstone, and algal-ball(?) limestone; some beds of large Paleozoic boulders and detachment masses of Paleozoic and Mesozoic rocks.