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Mineral Resources > Online Spatial Data > Geology > by state > Arkansas Geology

Geologic units in Arkansas (state in United States)

[Additional scientific data in this geographic area]

Annona Chalk (Phanerozoic | Mesozoic | Cretaceous-Late) at surface, covers < 0.1 % of this area
Annona Chalk
Lithology: limestone
Arkadelphia Marl (Phanerozoic | Mesozoic | Cretaceous-Late) at surface, covers 0.2 % of this area
Arkadelphia Marl
Lithology: mixed clastic/carbonate; clay or mud; sandstone; limestone
Brownstown Marl (Phanerozoic | Mesozoic | Cretaceous-Late) at surface, covers 0.2 % of this area
Brownstown Marl
Lithology: mixed clastic/carbonate; sand; limestone
De Queen Limestone (Phanerozoic | Mesozoic | Cretaceous-Early) at surface, covers < 0.1 % of this area
De Queen Limestone
Lithology: limestone
Dierks Limestone (Phanerozoic | Mesozoic | Cretaceous-Early) at surface, covers < 0.1 % of this area
Dierks Limestone
Lithology: limestone
Igneous rocks (Phanerozoic | Mesozoic | Cretaceous) at surface, covers < 0.1 % of this area
Includes undifferentiated altered sedimentary rocks of Paleozoic age at Granite Mountain, Pulaski County, and Mufreesboro, Pike County. Acid to intermediate - Nepheline syenite complexes at Magnet Cove and Potash Sulfur Springs, stocks at Granite Mtn., explosion breccias, and dikes and sills (principally trachyte,tinguaite, phonolite, some ranging from syenite to diabase.) Basic to ultrabasic - Lamproite pipes (Murfreesboro, Pike County) and dikes and sills (principally lamprophyres of fourchite, ouachitite, and monchiquite)
Lithology: alkalic intrusive rock; nepheline syenite; syenite; intrusive carbonatite; trachyte; lamprophyre
Kiamichi Formation and Goodland Limestone (Phanerozoic | Mesozoic | Cretaceous-Early) at surface, covers < 0.1 % of this area
Kiamichi Formation and Goodland Limestone
Lithology: mixed clastic/carbonate; carbonate; limestone
Marlbrook Marl (Phanerozoic | Mesozoic | Cretaceous-Late) at surface, covers < 0.1 % of this area
Marlbrook Marl
Lithology: mixed clastic/carbonate
Nacatoch Sand (Phanerozoic | Mesozoic | Cretaceous-Late) at surface, covers 0.2 % of this area
Nacatoch Sand
Lithology: sand; limestone; clay or mud; mixed clastic/carbonate
Ozan Formation (Phanerozoic | Mesozoic | Cretaceous-Late) at surface, covers 0.1 % of this area
Ozan Formation
Lithology: mixed clastic/carbonate
Cretaceous rocks (Phanerozoic | Mesozoic | Cretaceous) at surface, covers 0.1 % of this area
Cretaceous rocks
Lithology: clastic; carbonate
Sartoga Chalk (Phanerozoic | Mesozoic | Cretaceous-Late) at surface, covers < 0.1 % of this area
Sartoga Chalk
Lithology: limestone; sand
Sand and clay (Phanerozoic | Mesozoic | Cretaceous) at surface, covers < 0.1 % of this area
Sand and clay
Lithology: sand; clay or mud
Trinity Group (Phanerozoic | Mesozoic | Cretaceous-Early) at surface, covers 0.4 % of this area
Trinity Group
Lithology: sand; mixed clastic/carbonate; limestone; gypsum; novaculite
Tokio Formation (Phanerozoic | Mesozoic | Cretaceous-Late) at surface, covers 0.4 % of this area
Tokio Formation
Lithology: clay or mud; sand; coal; novaculite
Woodbine Formation (Phanerozoic | Mesozoic | Cretaceous-Late) at surface, covers 0.2 % of this area
Woodbine Formation
Lithology: volcanic rock (aphanitic); sand; gravel; clay or mud; sandstone
Boone Formation (Phanerozoic | Paleozoic | Carboniferous Mississippian-Early [Meramecian Osagean]) at surface, covers 0.4 % of this area
Boone Formation
Lithology: limestone; chert; shale
Arkansas Novaculite (Phanerozoic | Paleozoic | Devonian-Late Carboniferous Mississippian-Early) at surface, covers 0.4 % of this area
Arkansas Novaculite - Includes upper division (Mississippian), middle division (Mississippian and Devonian), and lower division (Devonian)
Lithology: novaculite; shale
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) at surface, covers 0.2 % of this area
Chattanooga Shale (Lower Mississippian and Upper Devonian), Clifty Limestone (Middle Devonian), and Penters Chert (Lower Devonian)
Lithology: shale; limestone; dolostone (dolomite); sandstone; siltstone; chert
Moorefield Formation (Phanerozoic | Paleozoic | Carboniferous Mississippian-Late [Meramecian]) at surface, covers < 0.1 % of this area
Moorefield Formation
Lithology: shale; limestone
Pitkin Limestone, Fayetteville Shale (including the Wedington Sandstone member), and Batesville Sandstone (including the Hindsville Limestone Member) (Phanerozoic | Paleozoic | Carboniferous Mississippian-Late [Chesterian]) at surface, covers 0.7 % of this area
Pitkin Limestone, Fayetteville Shale (including the Wedington Sandstone member), and Batesville Sandstone (including the Hindsville Limestone Member)
Lithology: sandstone; shale; limestone
Ruddell Shale (Phanerozoic | Paleozoic | Carboniferous Mississippian-Late [Chesterian]) at surface, covers < 0.1 % of this area
Ruddell Shale
Lithology: shale
Stanley Shale (Phanerozoic | Paleozoic | Carboniferous Mississippian-Early) at surface, covers 0.5 % of this area
Stanley Shale - Includes Chickasaw Creek Chert equivalent of Harlton (1938) near top and Hatton Tuff Lentil and Hot Springs Sandstone Member near base
Lithology: shale; sandstone; siltstone; chert; tuff
Blakely Sandstone (Middle and Lower Ordovician) (Phanerozoic | Paleozoic | Ordovician-Early Ordovician-Middle) at surface, covers 0.2 % of this area
Blakely Sandstone (Middle and Lower Ordovician)
Lithology: shale; sandstone; conglomerate
Collier Shale (Phanerozoic | Paleozoic | Ordovician-Early) at surface, covers < 0.1 % of this area
Collier Shale
Lithology: shale; limestone; chert
Cason Shale and Fernvale Limestone (Upper Ordovician) and Kimmswick Limestone, Plattin Limestone, and Joachim Dolomite (Middle Ordovician) (Phanerozoic | Paleozoic | Ordovician-Middle Ordovician-Late) at surface, covers 0.1 % of this area
Cason Shale and Fernvale Limestone (Upper Ordovician) and Kimmswick Limestone, Plattin Limestone, and Joachim Dolomite (Middle Ordovician)
Lithology: limestone; shale; sandstone
Cotter and Jefferson City Dolomites (Phanerozoic | Paleozoic | Ordovician-Early) at surface, covers 0.3 % of this area
Cotter and Jefferson City Dolomites
Lithology: dolostone (dolomite); chert; sandstone; shale
Crystal Mountain Sandstone (Phanerozoic | Paleozoic | Ordovician-Early) at surface, covers < 0.1 % of this area
Crystal Mountain Sandstone
Lithology: sandstone; shale; conglomerate
Mazarn Shale (Phanerozoic | Paleozoic | Ordovician-Early) at surface, covers 0.2 % of this area
Mazarn Shale
Lithology: shale; sandstone; limestone
Powell Dolomite (Phanerozoic | Paleozoic | Ordovician-Early) at surface, covers 0.4 % of this area
Powell Dolomite
Lithology: dolostone (dolomite); shale; sandstone; conglomerate
Pole Creek Shale (Upper Ordovician) and Bigfork Chert (Upper and Middle Ordovician) (Phanerozoic | Paleozoic | Ordovician-Middle Ordovician-Late) at surface, covers 0.4 % of this area
Polk Creek Shale (Upper Ordovician) and Bigfork Chert (Upper and Middle Ordovician)
Lithology: chert; shale; limestone
St. Peter Sanstone and Everton Formation (Middle Ordovician) (Phanerozoic | Paleozoic | Ordovician-Middle) at surface, covers 0.6 % of this area
St. Peter Sanstone and Everton Formation (Middle Ordovician)
Lithology: sandstone; dolostone (dolomite); limestone
Womble Shale (Middle Ordovician) (Phanerozoic | Paleozoic | Ordovician-Middle) at surface, covers 0.3 % of this area
Womble Shale (Middle Ordovician)
Lithology: shale; limestone; sandstone
Atoka Formation, undivided (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Atokan] ) at surface, covers 2 % of this area
Atoka Formation, undivided
Lithology: sandstone; shale; coal
Atoka Formation - Lower part (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Atokan]) at surface, covers 2 % of this area
Atoka Formation - Lower part
Lithology: sandstone; shale
Atoka Formation - Middle part (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Atokan]) at surface, covers 1 % of this area
Atoka Formation - Middle part
Lithology: sandstone; shale
Atoka Formation - Upper part (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Atokan]) at surface, covers 1.0 % of this area
Atoka Formation - Upper part
Lithology: sandstone; shale
Bloyd Shale, and Prairie Grove Member of the Hale Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Morrowan]) at surface, covers 1 % of this area
Bloyd Shale, and Prairie Grove Member of the Hale Formation
Lithology: sandstone; shale; limestone; conglomerate
Boggy Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Des Moinesian]) at surface, covers < 0.1 % of this area
Boggy Formation
Lithology: shale; sandstone
Cane Hill Member of Hale Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early [Morrowan]) at surface, covers 0.4 % of this area
Cane Hill Member of Hale Formation
Lithology: sandstone; siltstone; conglomerate
Harthshorne Sandstone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Des Moinesian]) at surface, covers 0.6 % of this area
Harthshorne Sandstone
Lithology: sandstone; shale; coal
Jackfork Sandstone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early [Morrowan]) at surface, covers 2 % of this area
Jackfork Sandstone
Lithology: sandstone; shale
Johns Valley Shale (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early [Morrowan]) at surface, covers 0.4 % of this area
Johns Valley Shale
Lithology: shale; sandstone; limestone
McAlester Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Des Moinesian]) at surface, covers 0.9 % of this area
McAlester Formation
Lithology: shale; sandstone; coal
Savanna Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Des Moinesian]) at surface, covers 0.4 % of this area
Savanna Formation
Lithology: shale; sandstone; coal
Olistoliths of Metagabbro and Soapstone-Serpentine (Phanerozoic | Paleozoic) at surface, covers < 0.1 % of this area
Olistoliths of Metagabbro and Soapstone-Serpentine - Altered peridotite
Lithology: gabbro; serpentinite
Alluvium (Phanerozoic | Cenozoic | Quaternary | Holocene) at surface, covers 2 % of this area
Alluvium - Alluvial deposits of present streams
Lithology: alluvium
Alluvium and terrace deposits (Phanerozoic | Cenozoic | Quaternary | Pleistocene Holocene) at surface, covers 0.1 % of this area
Alluvium and terrace deposits - Alluvial deposits of present streams and on one or more terrace levels
Lithology: alluvium; alluvial terrace
Alluvium - Alluvial deposits in major stream channels or in mappable meanders of major streams (Phanerozoic | Cenozoic | Quaternary | Holocene) at surface, covers 3 % of this area
Alluvial deposits in major stream channels or in mappable meanders of major streams - Includes alluvial deposits in natural levees in some areas.
Lithology: alluvium
Dune sand (Phanerozoic | Cenozoic | Quaternary | Pleistocene-Late) at surface, covers 0.7 % of this area
Dune sand - Deposited mostly on terrace deposits of the second level. Younger than some terrace deposits, older than others
Lithology: dune sand
Loess (Phanerozoic | Cenozoic | Quaternary | Pleistocene-Early) at surface, covers 0.2 % of this area
Loess
Lithology: loess
Sand and gravel (Phanerozoic | Cenozoic | Quaternary | Pleistocene-Early) at surface, covers < 0.1 % of this area
Sand and gravel
Lithology: sand; gravel
Alluvium - Alluvial deposits of local streams or of overbank flow of major streams (Phanerozoic | Cenozoic | Quaternary | Holocene) at surface, covers 7 % of this area
Alluvial deposits of local streams or of overbank flow of major streams - In some areas includes deposits in abandoned meanders of major streams
Lithology: alluvium
Silt and sand (Phanerozoic | Cenozoic | Quaternary | Pleistocene-Early) at surface, covers < 0.1 % of this area
Silt and sand - Contains lenses of gravel and clay
Lithology: silt; sand; gravel; clay or mud
Terrace deposits (Phanerozoic | Cenozoic | Quaternary | Pleistocene-Late) at surface, covers 11 % of this area
Terrace deposits - Alluvial deposits on one or more terrace levels
Lithology: alluvial terrace
Lafferty, St. Clair and Brassfield Limestones (Phanerozoic | Paleozoic | Silurian) at surface, covers < 0.1 % of this area
Lafferty, St. Clair and Brassfield Limestones
Lithology: limestone; mudstone
Missouri Mountain Shale and Baylock Sandstone (Phanerozoic | Paleozoic | Silurian) at surface, covers 0.2 % of this area
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
Lithology: sandstone; shale; conglomerate; siltstone
Claibourne Group (Phanerozoic | Cenozoic | Tertiary | Eocene-Middle) at surface, covers 1 % of this area
Claibourne Group
Lithology: sand; clay or mud; coal
Gravel (Phanerozoic | Cenozoic | Tertiary) at surface, covers < 0.1 % of this area
Gravel - Gravel on isolated hills within 40 miles (64km) of the Mississippi Embayment. Many small deposits to the west not shown
Lithology: gravel
Jackson Group (Phanerozoic | Cenozoic | Tertiary | Eocene-Late) at surface, covers 0.8 % of this area
Jackson Group
Lithology: mixed clastic/carbonate; silt; sand
Midway Group (Phanerozoic | Cenozoic | Tertiary | Paleocene) at surface, covers 0.5 % of this area
Midway Group
Lithology: clay or mud; mixed clastic/carbonate; sandstone; limestone
Wilcox Group (Phanerozoic | Cenozoic | Tertiary | Eocene-Early) at surface, covers 0.7 % of this area
Wilcox Group
Lithology: sand; silt; clay or mud; gravel; coal
Cockfield Formation (Phanerozoic | Cenozoic | Tertiary | Eocene) at surface, covers < 0.1 % of this area
brown lignitic clays, silts and sands; some sideritic glauconite may weather to brown ironstone in lower part.
Lithology: clay or mud; silt; sand
Cook Mountain Formation (Phanerozoic | Cenozoic | Tertiary | Eocene) at surface, covers < 0.1 % of this area
greenish gray sideritic clay in upper part may weather to brown ironstone; yellow to brown clays and fossiliferous marl in lower part may weather to black soil. Ironstone concretions near base.
Lithology: clay or mud; unconsolidated deposit
Alluvium (Phanerozoic | Cenozoic | Quaternary | Holocene) at surface, covers < 0.1 % of this area
gray to brownish gray clay and silty clay, reddish brown in the Red River Valley, some sand and gravel locally.
Lithology: clay or mud; sand; gravel
Braided Stream Terraces (Phanerozoic | Cenozoic | Quaternary | Pleistocene) at surface, covers < 0.1 % of this area
light gray, tan and brown fine to coarse sand; some clay silt and gravel.
Lithology: sand; clay or mud; silt; gravel
Natural Levees (Phanerozoic | Cenozoic | Quaternary | Holocene) at surface, covers < 0.1 % of this area
gray and brown silt, silty clay, some very fine sand, reddish brown along the Red River.
Lithology: silt; clay or mud; sand
KINDERHOOKIAN SERIES (Phanerozoic | Paleozoic | Carboniferous Mississippian-Early [Kinderhookian]) at surface, covers < 0.1 % of this area
KINDERHOOKIAN SERIES - NORTHVIEW SHALE, SEDALIA FORMATION, COMPTON LIMESTONE, BACHELOR FORMATION CHOUTEAU GROUP, HANNIBAL SHALE, HORTON CREEK LIMESTONE
Lithology: limestone; siltstone; shale; sandstone
OSAGEAN SERIES (Phanerozoic | Paleozoic | Carboniferous Mississippian-Early [Osagean]) at surface, covers < 0.1 % of this area
OSAGEAN SERIES - KEOKUK LIMESTONE, BURLINGTON LIMESTONE, ELSEY FORMATION, REEDS SPRING FORMATION, PIERSON LIMESTONE, FERN GLEN FORMATION
Lithology: limestone; chert; dolostone (dolomite); shale
SMITHVILLE DOLOMITE, POWELL DOLOMITE, COTTER DOLOMITE, JEFFERSON CITY DOLOMITE (Phanerozoic | Paleozoic | Ordovician-Early [Ibexian]) at surface, covers < 0.1 % of this area
SMITHVILLE DOLOMITE, POWELL DOLOMITE, COTTER DOLOMITE, JEFFERSON CITY DOLOMITE - fine crystalline, silty, cherty dolomite, and oolitic chert with local sandstone beds
Lithology: dolostone (dolomite); sandstone; shale; conglomerate; chert
HOLOCENE SERIES (Phanerozoic | Cenozoic | Quaternary | Holocene) at surface, covers < 0.1 % of this area
HOLOCENE SERIES - Alluvium - clay, silt, sand, and gravel
Lithology: clay or mud; silt; sand; gravel
Antlers Sand or Antlers Sandstone (Phanerozoic | Mesozoic | Cretaceous-Early ) at surface, covers < 0.1 % of this area
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.
Lithology: sandstone; mudstone; conglomerate; limestone
Brownstown Marl (Phanerozoic | Mesozoic | Cretaceous-Late ) at surface, covers < 0.1 % of this area
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.
Lithology: carbonate; clay or mud; sand; limestone
DeQueen Limestone (Phanerozoic | Mesozoic | Cretaceous-Early ) at surface, covers < 0.1 % of this area
McALESTER TEXARKANA- Limestone and marl, blue- to pinkish- to yellowish-gray, locally siliceous, interbedded with varicolored calcareous shales; basal limestone conglomerate in places where unconformable upon Ouachita rocks but absent where conformable on Holly Creek Formation; contains 80 feet of gypsum and anhydrite in subsurface; thickness, 38 feet, lensing out to 1 foot westward but thickening to 190 feet southeastward in subsurface.
Lithology: limestone; shale; conglomerate; evaporite
Goodland Limestone and Walnut Clay (Phanerozoic | Mesozoic | Cretaceous-Early ) at surface, covers < 0.1 % of this area
ARDMORE-SHERMAN- "Goodland Limestone," limestone, gray, dense, nodular to massive; thickness, 20 to 30 feet. At base is "Walnut Clay," tan clay, about 4 feet thick. McALESTER TEXARKANA- Limestone, white, fine crystalline, massive-bedded, with "Texigryphaea mucronata;" some argillaceous buff beds in lower few feet may be "Walnut Clay" equivalents; erodes into a mappable escarpment; thickness, 26 to 55 feet.
Lithology: limestone; mudstone
Holly Creek Formation (Phanerozoic | Mesozoic | Cretaceous-Early ) at surface, covers < 0.1 % of this area
McALESTER TEXARKANA- Gravel, composed mostly of quartz and novaculite, with clay and silt, tan to red-brown; unconformable on Ouachita rocks; thickness, 30 to 100 feet, thickening to 1,070 feet in subsurface of southern McCurtain County
Lithology: conglomerate; mudstone; siltstone
Kiamichi Formation (Phanerozoic | Mesozoic | Cretaceous-Early ) at surface, covers < 0.1 % of this area
ARDMORE-SHERMAN- Shale, dark-gray, plastic, with oyster-shell limestones; thickness, about 30 feet. McALESTER TEXARKANA- Shale, dark-gray to black, with some brown fossiliferous limestones, with "Texigryphaea navia;" thickness, 28 to 36 feet, and up to 80 feet in subsurface of southern McCurtain County.Ouachita Mountain uplift; S. OK folded belt province
Lithology: shale; limestone
Ozan Formation (Phanerozoic | Mesozoic | Cretaceous-Late ) at surface, covers < 0.1 % of this area
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.
Lithology: carbonate; clay or mud; sand; limestone
Woodbine Formation (Phanerozoic | Mesozoic | Cretaceous-Late) at surface, covers < 0.1 % of this area
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.
Lithology: sandstone; clay or mud; gravel; coal
Arkansas Novaculite (Phanerozoic | Paleozoic | Silurian Devonian(?) Carboniferous Mississippian-Early ) at surface, covers < 0.1 % of this area
McALESTER TEXARKANA- Chert, fine- to very fine-grained, gray, green, tan, black, white, and pink, with interbedded black to gray shale in 1-to 18-inch beds; some interbedded conglomerates and in places a basal conglomerate; upper part has been determined to be Mississippian in age and lower part to be Early Silurian, on basis of examination of palynomorphs from Potato Hills; thickness, 600 feet or more. Occurs in the OUACHITA MTNS SOUTH OF TI VALLEY FAULT.
Lithology: novaculite; shale; conglomerate
Keokuk and Reeds Spring Formations and St. Joe Group (Phanerozoic | Paleozoic | Carboniferous Mississippian-Early) at surface, covers < 0.1 % of this area
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.
Lithology: chert; limestone; shale; carbonate
Pitkin + Fayetteville + Hindsville + Moorefield Formations (Phanerozoic | Paleozoic | Carboniferous Mississippian-Late) at surface, covers < 0.1 % of this area
FORT SMITH- Mp "Pitkin Formation," limestone; "Fayetteville Formation," shale and limestone; "Hindsville Formation," limestone and shale; and "Moorefield Formation," limestone.
Lithology: limestone; shale
Stanley Group or Stanley Shale (Phanerozoic | Paleozoic | Carboniferous Mississippian) at surface, covers < 0.1 % of this area
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
Lithology: shale; sandstone; chert; tuff
Atoka Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle) at surface, covers < 0.1 % of this area
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.
Lithology: shale; sandstone; siltstone; limestone; conglomerate
Bloyd and Hale Formations (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early) at surface, covers < 0.1 % of this area
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.
Lithology: limestone; shale; sandstone
Jackfork Group or Jackfork Sandstone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early) at surface, covers < 0.1 % of this area
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
Lithology: sandstone; shale; chert
Johns Valley Formation or Johns Valley Shale (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early) at surface, covers < 0.1 % of this area
ARDMORE-SHERMAN- "Johns Valley Formation"- Shale, dark-gray, with boulder conglomerate; thickness, 425 to 900 feet. Occurs in the OUACHITA MNTS McALESTER TEXARKANA- "Johns Valley Shale"- Shale, dark-gray, with some stringers of Wapanucka-like limestone in northwestern part of area; contains exotic boulders of southern Arbuckle Mountain facies, ranging from Fort Sill to Goddard and as large as 369 feet in diameter; some Wapanucka nodules are not exotic but were formed in place; thickness, 300 to 1,000 feet. Occurs in the OUACHITA MTNS SOUTH OF TI VALLEY FAULT.
Lithology: shale; conglomerate; limestone
Lynn Mountain Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early) at surface, covers < 0.1 % of this area
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
Lithology: shale; sandstone
Alluvium (Phanerozoic | Cenozoic | Quaternary | Holocene) at surface, covers < 0.1 % of this area
WOODWARD- Lenticular and interfingering deposits of gravel, sand, silt, and clay. Generally light-tan to gray. Thickness along major streams ranges up to 100 feet and probably averages 40 feet; along minor streams the thickness ranges up to 45 feet and probably averages 20 feet. ENID- Sand, silt, clay, and locally gravel. Maximum thickness ranges from 30 to 80 feet (9 to 24 m) along major streams and from 0 to 60 feet (0 to 18 m) along minor streams. TULSA- Gravel, sand, silt, and clay. TULSA- Gravel, sand, silt, and clay. OKLAHOMA CITY- Sand, silt, clay, and lenticular beds of gravel. Thickness ranges from about 30 to 100 feet and probably averages about 50 feet along major streams. Along minor streams, thickness ranges from a few feet to about 50 feet and probably averages about 25 feet. LAWTON- Sand, clay, and gravel as much as 50 feet (15 m) thick; Shown only along major streams and tributaries . ARDMORE-SHERMAN- Gravel, sand, silt, and clay, including low terraces; thickness, about 25 to 100 feet. McALESTER TEXARKANA- Gravel, sand, silt, and clay, including low terraces about 30 feet above channels; thickness, about 50 feet along Little River and 110 feet along Red River
Lithology: alluvium
Terrace Deposits (Phanerozoic | Cenozoic | Quaternary | Pleistocene) at surface, covers < 0.1 % of this area
WOODWARD- Lenticular and interfingering deposits of light-tan to gray gravel, sand, silt, clay, and volcanic ash. Sand dunes are common in many places. Thickness ranges up to 150 feet and averages about 60 feet. ENID- Sand, silt, clay, and gravel. Maximum thickness, about 75 feet (23 m) along major streams. TULSA- Fine gravel, sand, silt, and clay. CLINTON- Stream-laid deposits of sand, silt, clay, gravel, and volcanic ash; thickness ranges from 0 to about 120 feet. OKLAHOMA CITY- Lenticular beds of sand, silt, clay, and gravel. Thickness ranges from a few feet to about 100 feet and probably averages about 50 feet along major streams. FORT SMITH- Gravel, sand, silt, and clay. LAWTON- Sand, clay, and gravel as much as 75 feet (23 m) in Tillman County, ranging from 5 to 50 feet (2 to 15 m) elsewhere. ARDMORE-SHERMAN- Gravel, sand, silt, clay, and volcanic ash; thickness, about 5 to 50 feet; at various levels, as high as 160 feet above present flood plains. McALESTER TEXARKANA- Gravel, sand, silt, clay, and volcanic ash; several levels 20 to 160 feet or more above present flood plains, with each level containing deposits that average 20 to 30 feet in thickness, some windblown sand on top; may include colluvial wash down sides of hills
Lithology: sand; gravel; volcanic ash
Blaylock Sandstone (Phanerozoic | Paleozoic | Silurian) at surface, covers < 0.1 % of this area
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
Lithology: sandstone; shale; phyllite
Missouri Mountain Shale (Phanerozoic | Paleozoic | Silurian) at surface, covers < 0.1 % of this area
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
Lithology: shale; phyllite; sandstone; conglomerate; limestone
Alluvial deposits (Quaternary) at surface, covers < 0.1 % of this area
Alluvial Deposits - Sand, silt, clay, and gravel. In flood plain of Mississippi River more than 100 feet thick; in smaller streams generally less than 20 feet thick.
Lithology: sand; silt; clay or mud; gravel
Wilcox Group, undivided (Phanerozoic | Cenozoic | Tertiary | Paleocene Eocene) at surface, covers < 0.1 % of this area
Wilcox Group, undivided
Lithology: fine-grained mixed clastic; coal; sand; clay or mud
Queen City Sand (Phanerozoic | Cenozoic | Tertiary | Eocene) at surface, covers < 0.1 % of this area
Queen City Sand
Lithology: sandstone; siltstone; clay or mud; sand
Reklaw Formation (Phanerozoic | Cenozoic | Tertiary | Eocene) at surface, covers < 0.1 % of this area
Reklaw Formation
Lithology: sandstone; clay or mud
Midway Group, undivided (Phanerozoic | Cenozoic | Tertiary | Paleocene) at surface, covers < 0.1 % of this area
Midway Group, undivided
Lithology: fine-grained mixed clastic; limestone; mudstone
alluvium (Phanerozoic | Cenozoic | Quaternary | Holocene) at surface, covers < 0.1 % of this area
alluvium
Lithology: sand; silt; clay or mud; gravel
Terrace deposits (Phanerozoic | Cenozoic | Quaternary | Pleistocene Holocene) at surface, covers < 0.1 % of this area
Terrace deposits
Lithology: terrace; sand; gravel; silt; clay or mud

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