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Geologic units containing limestone

Earth material > Sedimentary rock > Carbonate rock

Limestone

A sedimentary rock consisting chiefly (more than 50% by weight or by areal percentages under the microscope) of calcium carbonate, primarily in the form of the mineral calcite...

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Alabama

Athens Shale (Ordovician): Athens Shale - black graptolitic shale, locally contains interbedded dark-gray limestone.
Athens Shale and Lenoir Limestone undifferentiated (Ordovician): Athens Shale and Lenoir Limestone undifferentiated - Athens Shale -- black graptolitic shale, locally contains interbedded dark-gray limestone. Lenoir Limestone -- dark-gray medium to thick-bedded argillaceous limestone; locally contains an interval of fenestral mudstone at the base (Mosheim Limestone Member).
Bangor Limestone (Mississippian): Bangor Limestone - Medium-gray bioclastic and oolitic limestone, containing interbeds of dusky-red and olive-green mudstone in the upper part.
Bangor Limestone (Mississippian): Bangor Limestone - Medium-gray bioclastic and oolitic limestone, containing interbeds of dusky-red and olive-green mudstone in upper part.
Bangor Limestone (Mississippian): Bangor Limestone - Medium-gray bioclastic and oolitic limestone, containing interbeds of dusky-red and olive-green mudstone in upper part.
Bangor and Monteagle Limestones undivided in part (Mississippian): Bangor and Monteagle Limestones undivided in part - Bangor Limestone -- medium-gray bioclastic and oolitic limestone, containing interbeds of dusky-red and olive-green mudstone in upper part. Monteagle Limestone -- light-gray oolitic limestone containing interbedded argillaceous, bioclastic, or dolomitic limestone, dolomite, and medium-gray shale.
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.
Chepultepec and Copper Ridge Dolomites undifferentiated (Ordovician-Cambrian): Chepultepec and Copper Ridge Dolomites undifferentiated - Light-gray to dark-bluish-gray thick-bedded dolomite and interbedded light-gray limestone; includes abundant chert.
Chepultepec and Copper Ridge Dolomites undifferentiated (Ordovician-Cambrian): Chepultepec and Copper Ridge Dolomites undifferentiated - Light-gray to dark-bluish-gray thick-bedded dolomite and interbedded light-gray limestone; includes abundant chert.
Chepultepec and Copper Ridge Dolomites undifferentiated (Ordovician-Cambrian): Chepultepec and Copper Ridge Dolomites undifferentiated - Light-gray to dark-bluish-gray thick-bedded dolomite and interbedded light-gray limestone; includes abundant chert.
Chickamauga Limestone (Ordovician): Chickamauga Limestone - Medium to dark-gray thick to thin-bedded partly argillaceous, locally fossiliferous limestone. Restricted to the western part of the Valley and Ridge province and Murphrees Valley and Wills Valley anticlines. Locally includes a thin interval of Attalla Chert Conglomerate Member at base. Attalla Chert Conglomerate - conglomerate of pebbles, cobbles, and boulders of chert and rare dolomite and quartzite in a sand-sized matrix; thin beds of gray-green or dusky-red shale common at base.
Chickamauga Limestone (Ordovician): Chickamauga Limestone - Medium to dark-gray thick to thin-bedded partly argillaceous, locally fossiliferous limestone. Restricted to the western part of the Valley and Ridge province and Murphrees Valley and Wills Valley anticlines. Locally includes a thin interval of Attalla Chert Conglomerate Member at base. Attalla Chert Conglomerate - conglomerate of pebbles, cobbles, and boulders of chert and rare dolomite and quartzite in a sand-sized matrix; thin beds of gray-green or dusky-red shale common at base.
Conasauga Formation (Cambrian): Conasauga Formation - medium-bluish-gray fine-grained, thin-bedded argillaceous limestone and interbedded dark-gray shale in varying proportions.
Conasauga Formation (Cambrian): Conasauga Formation - Medium-bluish-gray fine-grained, thin-bedded argillaceous limestone and interbedded dark-gray shale in varying proportions.
Conasauga Formation, lower unnamed shale facies (Cambrian): Conasauga Formation, lower unnamed shale facies - lower unnamed shale facies in eastern Valley and Ridge consists of dark-green to pale-olive fossiliferous shale with a few dark-gray limestone interbeds.
Fort Payne Chert (Mississippian): Fort Payne Chert - Very light to light-olive-gray, thin to thick-bedded fine to coarse-grained bioclastic (abundant pelmatozoans) limestone containing abundant nodules, lenses and beds of light to dark-grey chert. Upper part of formation locally consists of light-bluish-gray laminated siltstone containing vugs lined or filled with quartz and scattered throughout the formation are interbeds of medium to greenish-gray shale, shaly limestone and siltstone. Commonly present below the Fort Payne is a light-olive-gray claystone or shale (Maury Formation) which is mapped with the Fort Payne.
Fort Payne Chert (Mississippian): Fort Payne Chert - Very light to light-olive-gray, thin to thick-bedded fine to coarse-grained bioclastic (abundant pelmatozoans) limestone containing abundant nodules, lenses and beds of light to dark-grey chert. Upper part of formation locally consists of light-bluish-gray laminated siltstone containing vugs lined or filled with quartz and scattered throughout the formation are interbeds of medium to greenish-gray shale, shaly limestone and siltstone. Commonly present below the Fort Payne is a light-olive-gray claystone or shale (Maury Formation) which is mapped with the Fort Payne. The apparent thickness of the Fort Payne in this province varies due to differnetial dissolution of carbonate in the formation.
Inman Formation (Ordovician): Inman Formation - interbedded greenish-gray or moderate to dusky-red shale and light-gray peloidal limestone. Mapped in Sequatchie Valley.
Jackson Group undifferentiated (Eocene): Jackson Group undifferentiated - The units of the Jackson Group are the Yazoo Clay and Crystal River and Moodys Branch Formations. Descriptions of the members of the Yazoo Clay follow in decending order. Shubuta Member - in western Alabama consists of light-greenish-gray to white plastic fossiliferous, calcareous clay containing irregular calcareous nodules. From the Tombigbee River eastward the Shubuta becomes more calcareous and grades into massive clayey glauconitic limestone. Eastward from the Alabama River , equivalent beds grade into the Crystal River Formation. Pachuta Marl Member - light-greenish-grey glauconitic, fossiliferous clayey sand and sandy limestone traceable from western Alabama eastward to Covington County where it grades into the Crystal River Formation. Cocoa Sand Member - yellowish-gray firm calcareous, fossiliferous fine to medium sand or sandy limestone or greenish-grey micaceous, calcareous, very clayey sand. Calcareous and clayey sand equivalent to the Cocoa is traceable from western Alabama to the Conecuh River area. North Twistwood Creek Clay Member - greenish-gray plastic calcareous, sparsely fossiliferous, blocky massive clay; grades into Crystal River formation in southeast AL. Crystal River Formation - white to yellowish-grey medium-grained to coquinoid limestone that is soft and chalky to compact and brittle; principally in southeastern AL but interfingers westward with members of the Yazoo Clay. Moodys Branch Formation - greenish-gray to pale-yellowish-orange glauconitic, calcareous, fossiliferous sand and sandy limestone; underlies the Yazoo Clay and the Crystal River Formation.
Knox Group undifferentiated (Ordovician-Cambrian): Knox Group undifferentiated - Light-gray to light-brown locally sandy dolomite, dolomitic limestone, and limestone; characterized by abundant light-colored chert.
Knox Group undifferentiated in part (Ordovician-Cambrian): Knox Group undifferentiated in part - light-gray to light-brown locally sandy dolomite, dolomitic limestone, and limestone; characterized by abundant light-colored chert.
Leipers Limestone (Ordovician): Leipers Limestone - Leipers Limestone -- medium to dark-gray thin to medium-bedded fossiliferous limestone containing interbeds of thin argillaceous limestone. Mapped in Sequatchie Valley. Inman Formation -- interbedded greenish-gray or moderate to dusky-red shale and light-gray peloidal limestone. Mapped in Sequatchie Valley.
Little Oak Limestone (Ordovician): Little Oak Limestone - dark-gray medium to thick-bedded fossiliferous, argillaceous to silty limestone containing chert nodules. Locally includes thin beds of bentonite in the upper part.
Little Oak and Lenoir Limestones undifferentiated (Ordovician): Little Oak and Lenoir Limestones undifferentiated - dark-gray argillaceous, fossiliferous medium to thick-bedded limestone; locally contains rare chert in upper part and an interval of fenestral mudstone in lower part (Mosheim Limestone Member of the Lenoir Limestone). Between Siluria and Pelham in Shelby County, the Little Oak and Lenoir Limestones are seperated by a tongue of the Athens Shale.
Little Oak and Newala Limestones undifferentiated (Ordovician): Little Oak and Newala Limestones undifferentiated - Little Oak Limestone -- dark-gray medium to thick-bedded fossiliferous, argillaceous to silty limestone containing chert nodules. Locally includes thin beds of bentonite in the upper part. Newala Limestone -- light to dark-gray thick-bedded micritic and peloidal limestone and minor dolomite.
Longview Limestone (Ordovician): Longview Limestone - light to medium-gray thick-bedded cherty limestone and dolomite, locally sandy.
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).
Midway Group; Porters Creek Formation (Paleocene): Porters Creek Formation - (Midway Group), dark-gray massive plastic clay in western AL with a thin bed of glauconitic shell marl at the top (Mathews Landing Marl Member). Becomes calcareous eastward grading into light-greenish-gray calcareous, micaceous, clayey fine to medium sand, medium-gray sandy, calcareous clay and white to light-gray thin bedded partly clayey, fossiliferous limestone. East of Crenshaw County, owing to lithologic similarity, beds correlative with the Porters Creek are included in the Clayton Formation.
Monteagle Limestone (Mississippian): Monteagle Limestone - Light-gray oolitic limestone containing interbedded argillaceous, bioclastic, or dolomitic limestone, dolomite, and medium-gray shale.
Monteagle Limestone (Mississippian): Monteagle Limestone - Light-gray oolitic limestone containing interbedded argillaceous, bioclastic, or dolomitic limestone, dolomite, and medium-gray shale.
Monteagle Limestone (Mississippian): Monteagle Limestone - Light-gray oolitic limestone containing interbedded argillaceous, bioclastic, or dolomitic limestone, dolomite, and medium-gray shale.
Nashville Group (Ordovician): Nashville Group - medium- to dark-gray argillaceous and fossiliferous limestone overlain by yellowish-gray laminated silty limestone. Mapped seperately from the Stone River Group only in Jackson County.
Nashville and Stones River Groups undifferentiated (Ordovician): Nashville and Stones River Groups undifferentiated - medium to dark-gray fossiliferous limestone, argillaceous in part; yellowish-gray laminated silty limestone in upper part. Contains one or more thin beds of bentonite and bentonitic shale.
Newala Limestone (Ordovician): Newala Limestone - light to dark-gray thick-bedded micritic and peloidal limestone and minor dolomite.
Newala and Longview Limestones undifferentiated (Ordovician): Newala and Longview Limestones undifferentiated - light to dark-grey thick-bedded limestone and dolomite, cherty in part.
Oligocene Series undifferentiated (Oligocene): Oligocene Series undifferentiated - Descriptions of the units of the Oligocene Series follow in descending order. Paynes Hammock Sand - locally fossiliferous, calcareous, argillaceous medium to coarse sand; pale-blue-green clay; and thin-bedded sandy limestone; exposed at Paynes Hammock and at St. Stephens. Chickasawhay Limestone - white to yellowish-gray fossiliferous, glauconitic limestone and soft marl. Byram Formation includes three members in descending order: Bucatunna Clay Member - dark, bentonitic, carbonaceous, sparsely fossiliferous clay and greyish-yellow sand; unnamed marl member - light-grey to yellowish-grey sandy, glauconitic , fossiliferous marl; Glendon Limestone Member - irregularly indurated coquinoid and crystalline limestone, weathering to indurated rock containing large tubular cavities, locally known as 'horsebone'. Marianna Limestone - white to yellowish-grey soft, porous, very fossiliferous limestone. Forest Hill sand - dark-greenish-grey carbonaceous clay with lenses of glauconitic fossiliferous sand; extends eastward from MS into Choctaw, Clarke and Washington Counties. Red Bluff Clay - greenish-gray calcareous clay locally containing selenite crystals, yellowish-grey glauconitic, fossiliferous limestone; and light-gray silty clay with interbeds of sand (Forest Hill equivalent); from Tombigbee River eastward grades into glauconitic fossiliferous limestone equivalent to the Bumpnose Limestone. Bumpnose Limestone - very light-gray to yellowish-gray chalky, subcoquinoid, glauconitic, argillaceous, fossiliferous limestone; intertongues with Red Bluff Clay in vicinity of the Alabama River and is readily differentiated eastward from the Sepulga River.
Ordovician System undivided in part (Includes Sequatchie Formation, Elkmont Formation, Leipers Limestone, Inman Formation, Nashville Group, and Stones River Group) (Ordovician): Ordovician System undivided in part (Includes Sequatchie Formation, Elkmont Formation, Leipers Limestone, Inman Formation, Nashville Group, and Stones River Group) - Sequatchie Formation -- grayish-red and yellowish-gray calcareous shale containing interbedded fossiliferous limestone. Elkmont Formation -- medium to dark-gray phosphatic limestone with interbeds of light to medium-gray and black shale. Leipers Limestone -- medium to dark-gray thin to medium-bedded fossiliferous limestone containing interbeds of argillaceous limestone. Inman Formation -- interbedded greenish-gray or moderate to dusky-red shale and light-gray peloidal limestone. Nashville Group undifferentiated -- medium to dark-gray argillaceous and fossiliferous limestone overlain by yellowish-gray laminated silty limestone. Stones River Group -- medium to dark-gray thick to thin-bedded limestone, argillaceous in part, locally very fossiliferous.
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.
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.
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.
Pride Mountain Formation and Monteagle Limestone undifferentiated (Mississippian): Pride Mountain Formation and Monteagle Limestone undifferentiated - Light-gray oolitic limestone, argillaceous and in part bioclastic with interbeds of medium to dark-gray shale.
Sequatchie Formation (Ordovician): Sequatchie Formation - Grayish-red, grayish-green, and yellowish-gray thin-bedded calcareous shale and calcareous mudstone containing interbedded fossiliferous limestone, and medium-gray to moderate-red partly sandy and glauconitic, medium to coarse-grained bioclastic limestone.
Sequatchie Formation (Ordovician): Sequatchie Formation - light-olive-gray and dusky-red calcareous shale interbedded with light to dark-gray fine to coarse-grained partly bioclastic, argillaceous, locally glauconitic limestone.
Sequatchie Formation (Ordovician): Sequatchie Formation - Grayish-red, grayish-green, and yellowish-gray thin-bedded calcareous shale and calcareous mudstone containing interbedded fossiliferous limestone, and medium-gray to moderate-red partly sandy and glauconitic, medium to coarse-grained bioclastic limestone. In Jackson County, includes the Leipers Limestone and Inman Formation.
Silurian System undivided (Includes Wayne Group and Brassfield Limestone) (Silurian): Silurian System undivided (Includes Wayne Group and Brassfield Limestone) - Wayne Group - medium-gray, greenish-gray, and moderate-red argillaceous limestone; moderate-red and greenish-gray shale; and grayish-green fossiliferous limestone with scattered pink calcite crystals. Brassfield Limestone - greenish-gray to light-brownish-gray argillaceous, dolomitic, cherty, sandy, glauconitic limestone.
Stones River Groups undifferentiated in part (Ordovician): Stones River Groups undifferentiated in part - medium to dark-gray thick to thin-bedded limestone, argillaceous in part, locally very fossiliferous. Contains a zone of bentonite and bentonitic shale near the top. Mapped seperately from the Nashville Group only in Jackson County.
Tuscumbia Limestone (Mississippian): Tuscumbia Limestone - Light-gray partly oolitic limestone; very coarse bioclastic crinoidal limestone common; light-gray chert nodules and concretions locally abundant.
Tuscumbia Limestone (Mississippian): Tuscumbia Limestone - Light-gray limestone, partly oolitic near top; fine to very coarse-grained bioclastic crinoidal limestone common; light-gray chert nodules and concretions are scattered throughout and are abundant locally. The apparent thickness of the formation in this province varies due to differential dissolution of the carbonate in the unit.
Tuscumbia Limestone and Fort Payne Chert undifferentiated (Mississippian): Tuscumbia Limestone and Fort Payne Chert undifferentiated - Tuscumbia Limestone -- light to dark-gray fossiliferous and oolitic partly argillaceous and cherty limestone. Apparently present only along part of the northwest limb of the Coosa synclinorium. Fort Payne Chert -- dark-gray to light-gray limestone with abundant irregular light-gray chert nodules and beds. Commonly present below the Fort Payne is greenish-gray to grayish-red phosphatic shale (Maury Formation) which is mapped with the Tuscumbia Limestone and Fort Payne Chert undifferentiated.
Tuscumbia Limestone and Fort Payne Chert undifferentiated (Mississippian): Tuscumbia Limestone and Fort Payne Chert undifferentiated - Tuscumbia Limestone -- light to dark-gray fossiliferous and oolitic partly argillaceous and cherty limestone, absent locally and too thin to map seperately. Fort Payne Chert -- dark-gray to light-gray limestone with abundant irregular light-gray chert nodules and beds. Commonly present below the Fort Payne is greenish-gray to grayish-red phosphatic shale (Maury Formation) which is mapped with the Tuscumbia Limestone and Fort Payne Chert undifferentiated.
Tuscumbia Limestone and Fort Payne Chert undivided (Mississippian): Tuscumbia Limestone and Fort Payne Chert undivided - Tuscumbia Limestone -- light-gray partly oolitic limestone; very coarse bioclastic crinoidal limestone common; light-gray chert nodules and concretions locally abundant. Fort Payne Chert -- very light to light-olive-gray, thin to thick-bedded fine to coarse-grained bioclastic (abundant pelmatozoans) limestone containing abundant nodules, lenses and beds of light to dark-grey chert. Upper part of formation locally consists of light-bluish-gray laminated siltstone containing vugs lined or filled with quartz and scattered throughout the formation are interbeds of medium to greenish-gray shale, shaly limestone and siltstone. Lenses of dark-gray siliceous shale occur locally at the base of the Fort Payne in Wills Valley. Commonly present below the Fort Payne is a ligh-olive-gray claystone or shale (Maury Formation) which is mapped with the Fort Payne. The Tuscumbia and Fort Payne are undifferentiated in Murphrees and Wills Valleys.
Wilcox Group; Salt Mountain Limestone (Paleocene): Salt Mountain Limestone - (Wilcox Group), White massive, indurated fossiliferous limestone containing lenses and irregular beds of soft, friable limestone. Exposed only at Salt Mountain, on the upthrow side of the Jackson fault 5 miles south of Jackson, Clarke County.

Arkansas

Annona Chalk (Phanerozoic | Mesozoic | Cretaceous-Late): Annona Chalk
Boone Formation (Phanerozoic | Paleozoic | Carboniferous Mississippian-Early [Meramecian Osagean]): Boone Formation
Brownstown Marl (Phanerozoic | Mesozoic | Cretaceous-Late): Brownstown Marl
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)
Collier Shale (Phanerozoic | Paleozoic | Ordovician-Early): Collier Shale
De Queen Limestone (Phanerozoic | Mesozoic | Cretaceous-Early): De Queen Limestone
Dierks Limestone (Phanerozoic | Mesozoic | Cretaceous-Early): Dierks Limestone
Johns Valley Shale (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early [Morrowan]): Johns Valley Shale
Kiamichi Formation and Goodland Limestone (Phanerozoic | Mesozoic | Cretaceous-Early): Kiamichi Formation and Goodland Limestone
Lafferty, St. Clair and Brassfield Limestones (Phanerozoic | Paleozoic | Silurian): Lafferty, St. Clair and Brassfield Limestones
Mazarn Shale (Phanerozoic | Paleozoic | Ordovician-Early): Mazarn Shale
Moorefield Formation (Phanerozoic | Paleozoic | Carboniferous Mississippian-Late [Meramecian]): Moorefield Formation
Nacatoch Sand (Phanerozoic | Mesozoic | Cretaceous-Late): Nacatoch Sand
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)
Pole Creek Shale (Upper Ordovician) and Bigfork Chert (Upper and Middle Ordovician) (Phanerozoic | Paleozoic | Ordovician-Middle Ordovician-Late): Polk Creek Shale (Upper Ordovician) and Bigfork Chert (Upper and Middle Ordovician)
Sartoga Chalk (Phanerozoic | Mesozoic | Cretaceous-Late): Sartoga Chalk
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)

Arizona

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)
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)

California

Carboniferous marine rocks, unit 1 (Western Mojave Desert) (Late Proterozoic to Pennsylvanian): Shale, sandstone, conglomerate, limestone, dolomite, chert, hornfels, marble, quartzite; in part pyroclastic rocks
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 3 (SE California Clastic Assemblage) (Late Devonian to Early Permian): Shale, sandstone, conglomerate, limestone, dolomite, chert, hornfels, marble, quartzite; in part pyroclastic rocks
Devonian marine rocks, unit 1 (Death Valley) (Middle to Late Devonian): Limestone and dolomite, sandstone and shale; in part tuffaceous
Limestone of probable Paleozoic or Mesozoic age (Paleozoic to Mesozoic): Limestone, dolomite, and marble whose age is uncertain but probably Paleozoic or Mesozoic
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
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
Permian marine sedimentary rocks, unit 4 (Eastern Klamath Mountains) (Early Permian): Shale, conglomerate, limestone and dolomite, sandstone, slate, hornfels, quartzite; minor pyroclastic rocks
Silurian and/or Ordovician marine rocks, unit 1 (Death Valley) (Ordovician to Early Devonian): Sandstone, shale, conglomerate, chert, slate, quartzite, hornfels, marble, dolomite, phyllite; some greenstone
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 4 (West Walker River) (Triassic(?)): Shale, conglomerate, limestone and dolomite, sandstone, slate, hornfels, quartzite; minor pyroclastic rocks
Triassic marine rocks, unit 5 (Northern Sierra Nevada) (Middle to Late Triassic): Shale, conglomerate, limestone and dolomite, sandstone, slate, hornfels, quartzite; minor pyroclastic rocks

Colorado

Belden Fm (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian): Shale, limestone, and sandstone. Includes Kerber Fm in south-central
Carlile Shale, Greenhorn Limestone, and Graneros Shale (Phanerozoic | Mesozoic | Cretaceous)
Colorado Group (Phanerozoic | Mesozoic | Cretaceous): Consists of Niobrara Formation (Kn) and either Benton Shale or Carlile, Greenhorn, and Graneros Fms (Kcg)
Dakota, Burro Canyon, Morrison, and Wanakah 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)
Dockum Group (Phanerozoic | Mesozoic | Triassic): Red sandstone, siltstone, and local limestone
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
Leadville Limestone, Gilman Sandstone, Dyer Dolomite, and Parting Fm (Phanerozoic | Paleozoic | Ordovician Silurian(?) Devonian): Parting Fm: quartzite and shale.
Leadville Limestone, Williams Canyon Limestone , Manitou Limestone, and Sawatch Quartzite (Phanerozoic | Paleozoic | Cambrian Ordovician(?) Silurian(?) Devonian(?) Carboniferous)
Leadville Limestone, Williams Canyon Limestone, and one or more of: Fremont Limestone, Harding Sandstone, and Manitou Limestone (Phanerozoic | Paleozoic | Ordovician Silurian(?) Devonian(?) Carboniferous Mississippia)
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.
Lykins Fm (Phanerozoic | Paleozoic Mesozoic | Permian Triassic): Red siltstone, shale, and limestone
Lykins Fm and Lyons Sandstone (Phanerozoic | Paleozoic Mesozoic | Permian Triassic)
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)
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.
Morgan Fm and Round Valley Limestone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian): Morgan Fm: limestone, sandstone, and shale. In far northwest.
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 Sundance Fm (Phanerozoic | Mesozoic | Jurassic): Sundance Fm: Sandstone, shale, claystone, and limestone
Morrison, Wanakah, and Entrada Fms (Phanerozoic | Mesozoic | Jurassic)
Niobrara Fm (Phanerozoic | Mesozoic | Cretaceous): Calcareous shale and limestone
One or more Ordovician fms (Phanerozoic | Paleozoic | Ordovician): Fremont Limestone, Harding Sandstone, and Manitou Limestone
Pierre Shale (Kp), Niobrara (Kn), and Carlile, Greenhorn, and Graneros (Kcg) Fms, undivided (Phanerozoic | Mesozoic | Cretaceous)
Williams Canyon Limestone, Manitou Limestone, and Sawatch Quartzite (Phanerozoic | Paleozoic | Cambrian Ordovician(?) Silurian(?) Devonian)

Delaware

Cockeysville Marble (Paleozoic): Cockeysville Marble - Dense, white crystalline limestone and dolomite.

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.
Anastasia Formation (Pleistocene): Anastasia Formation - The Atlantic Coastal Ridge is underlain by the Anastasia Formation from St. Johns County southward to Palm Beach County. Excellent exposures occur in Flagler County in Washington Oaks State Park, in Martin County at the House of Refuge on Hutchinson Island and at Blowing Rocks in Palm Beach County. An impressive exposure of Anastasia Formation sediments occurs along Country Club Road in Palm Beach County (Lovejoy, 1992). The Anastasia Formation generally is recognized near the coast but extends inland as much as 20 miles (32 kilometers) in St. Lucie and Martin Counties. The Anastasia Formation, named by Sellards (1912),is composed of interbedded sands and coquinoid limestones. The most recognized facies of the Anastasia sediments is an orangish brown, unindurated to moderately indurated, coquina of whole and fragmented mollusk shells in a matrix of sand often cemented by sparry calcite. Sands occur as light gray to tan and orangish brown, unconsolidated to moderately indurated, unfossiliferous to very fossiliferous beds. The Anastasia Formation forms part of the surficial aquifer system.
Avon Park Formation (Eocene): Avon Park Formation - Middle Eocene carbonate sediments of peninsular Florida, as originally described by Applin and Applin (1944), were subdivided, in ascending order, into the Lake City Limestone and the Avon Park Limestone. Miller (1986) recommended combining the Lake City Limestone with the Avon Park Limestone and, due to the common occurrence of dolostone, referred to the unit as the Avon Park Formation. Carbonates of the Avon Park Formation are the oldest sediments exposed in the state. The Avon Park Formation crops out in a limited area in west-central peninsular Florida in Levy and Citrus Counties on the crest of the Ocala Platform. The Avon Park Formation consists of cream to light-brown or tan, poorly indurated to well indurated, variably fossiliferous, limestone (grainstone, packstone and wackestone, with rare mudstone). These limestones are interbedded with tan to brown, very poorly indurated to well indurated, very fine to medium crystalline, fossiliferous (molds and casts), vuggy dolostones. The fossils present include mollusks, foraminifers, echinoids, algae and carbonized plant remains. Molds and casts of gypsum crystals occur locally. The Avon Park Formation is part of the Floridan aquifer system (FAS). Parts of the Avon Park Formation comprise important, subregional confining units within the FAS (Miller, 1986).
Hawthorn Group, Arcadia Formation (Oligocene/Miocene): Hawthorn Group, Arcadia Formation - The undifferentiated Arcadia Formation and the Tampa Member crop out on the southwestern flank of the Ocala Platform from Pasco County southward to Sarasota County. Although ages of the outcropping sediments have not been accurately determined, stratigraphic position suggests that the Upper Oligocene parts of the Arcadia Formation and Tampa Member are exposed in this region, particularly from Hillsborough County northward to Pasco County. The Arcadia Formation, named by Scott (1988), is predominantly a carbonate unit with a variable siliciclastic component, including thin beds of siliciclastics. Within the outcrop area, the Arcadia Formation, with the exception of the Tampa Member, is composed of yellowish gray to light olive gray to light brown, micro to finely crystalline, variably sandy, clayey, and phosphatic, fossiliferous limestones and dolostones. Thin beds of sand and clay are common. The sands are yellowish gray, very fine to medium grained, poorly to moderately indurated, clayey, dolomitic and phosphatic. The clays are yellowish gray to light olive gray, poorly to moderately indurated, sandy, silty, phosphatic and dolomitic. Molds and casts of mollusks are common in the dolostones. Silicified carbonates and opalized claystone are found in the Arcadia Formation.
Hawthorn Group, Arcadia Formation, Tampa Member (Oligocene/Miocene): Hawthorn Group, Arcadia Formation, Tampa Member - The Tampa Member consists predominantly of limestone with subordinate dolostone, sand and clay (Scott, 1988). The lithology of the Tampa Member is very similar to that of the subsurface limestone part of the Arcadia Formation except that the Tampa Member contains noticeably less phosphate (Scott, 1988). The limestone in the Tampa is white to yellowish gray, fossiliferous and variably sandy and clayey mudstone, wackestone and packstone with minor to no phosphate grains. Sand and clay beds are like those in the undifferentiated Arcadia Formation. Mollusks and corals are common in the Tampa Member as molds and casts, silicified pseudomorphs and original shell material. The Tampa Member and the lower part of the Arcadia Formation form the upper part of the Floridan aquifer system (FAS) in parts of southern Florida (Miller, 1986; Scott, 1991).
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.
Intracoastal Formation (Pliocene): Intracoastal Formation - Limited exposures and shallow subsurface occurrences of the Intracoastal Formation have been reported in northwestern Florida (Bay, Franklin, Liberty and Wakulla Counties) (Schmidt, 1984). In the subsurface, it occurs to the west across the Apalachicola Embayment (Huddlestun, 1984; Schmidt, 1984). The Intracoastal Formation is composed of light gray to olive gray, poorly indurated, sandy, clayey, highly fossiliferous limestone (grainstone and packstone). The fossils present include foraminifers, mollusks, barnacles, echinoids and ostracods. Quartz sand varies from very fine to coarse grained (Huddlestun, 1984).
Key Largo Limestone (Pleistocene): Key Largo Limestone - The Key Largo Limestone, named by Sanford (1909), is exposed at the surface in the Florida Keys from Soldier Key on the northeast to Newfound Harbor Keys near Big Pine Key on the southwest (Hoffmeister, 1974). This unit is a fossil coral reef much like the present day reefs offshore from the Keys. An exceptional exposure of the Key Largo Limestone occurs in the Windley Key Quarry State Geological Site in the upper Florida Keys. Exposures of the limestone containing large coral heads are in a series of old quarries. The Key Largo Limestone is a white to light gray, moderately to well indurated, fossiliferous, coralline limestone composed of coral heads encased in a calcarenitic matrix. Little to no siliciclastic sediment is found in these sediments. Fossils present include corals, mollusks and bryozoans. It is highly porous and permeable and is part of the Biscayne Aquifer of the surficial 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.
Ocala Limestone (Eocene): Ocala Limestone - Dall and Harris (1892) referred to the limestones exposed near Ocala, Marion County, in central peninsular Florida as the Ocala Limestone. Puri (1953, 1957) elevated the Ocala Limestone to group status recognizing its component formations on the basis of foraminiferal faunas (biozones). Scott (1991) reduced the Ocala Group to formational status in accordance with the North American Stratigraphic Code (North American Commission on Stratigraphic Nomenclature, 1983). The Ocala Limestone consists of nearly pure limestones and occasional dolostones. It can be subdivided into lower and upper facies on the basis of lithology. The lower member is composed of a white to cream-colored, fine to medium grained, poorly to moderately indurated, very fossiliferous limestone (grainstone and packstone). The lower facies may not be present throughout the areal extent of the Ocala Limestone and may be partially to completely dolomitized in some regions (Miller, 1986). The upper facies is a white, poorly to well indurated, poorly sorted, very fossiliferous limestone (grainstone, packstone and wackestone). Silicified limestone (chert) is common in the upper facies. Fossils present in the Ocala Limestone include abundant large and smaller foraminifers, echinoids, bryozoans and mollusks. The large foraminifera Lepidocyclina sp. is abundant in the upper facies and extremely limited in the lower facies. The presence of these large foraminifers in the upper facies is quite distinctive. The Ocala Limestone is at or near the surface within the Ocala Karst District in the westcentral to northwestern peninsula and within the Dougherty Plain District in the north-central panhandle (Scott, in preparation). In these areas, the Ocala Limestone exhibits extensive karstification. These karst features often have tens of feet (meters) of relief, dramatically influencing the topography of the Ocala Karst District and the Dougherty Plain District (Scott, in preparation). Numerous disappearing streams and springs occur within these areas. The permeable, highly transmissive carbonates of the Ocala Limestone form an important part of the FAS. It is one of the most permeable rock units in the FAS (Miller, 1986).
Residuum on Eocene sediments (Eocene): Residuum on Eocene sediments - The post-Eocene residuum lying on Eocene sediments in the panhandle consists of reddish brown, sandy clays and clayey sands with inclusions of weathered Eocene limestones. Some of the inclusions are silicified carbonates.
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.
Residuum on Oligocene sediments (Oligocene): Residuum on Oligocene sediments - The undifferentiated Oligocene residuum, mapped on parts of the Chattahoochee "Anticline", characteristically consists of reddish brown, variably sandy clay with inclusions of variably fossiliferous, silicified limestone (Huddlestun, 1993). The residuum includes Lower and Upper Oligocene weathered sediments (Huddlestun, 1993).
Shelly sediments of Plio-Pleistocene age (Pliocene/Pleistocene): Shelly sediments of Plio-Pleistocene age - Tertiary-Quaternary Fossiliferous Sediments of Southern Florida - Molluskbearing sediments of southern Florida contain some of the most abundant and diverse fossil faunas in the world. The origin of these accumulations of fossil mollusks is imprecisely known (Allmon, 1992). The shell beds have attracted much attention due to the abundance and preservation of the fossils but the biostratigraphy and lithostratigraphy of the units has not been well defined (Scott, 1992). Scott and Wingard (1995) discussed the problems associated with biostratigraphy and lithostratigraphy of the Plio-Pleistocene in southern Florida. These "formations" are biostratigraphic units. The "formations" previously recognized within the latest Tertiary-Quaternary section of southern Florida include the latest Pliocene - early Pleistocene Caloosahatchee Formation, the early Pleistocene Bermont formation (informal) and the late Pleistocene Fort Thompson Formation. This section consists of fossiliferous sands and carbonates. The identification of these units is problematic unless the significant molluscan species are recognized. Often exposures are not extensive enough to facilitate the collection of representative faunal samples to properly discern the biostratigraphic identification of the formation. In an attempt to alleviate the inherent problems in the biostratigraphic recognition of lithostratigraphic units, Scott (1992) suggested grouping the latest Pliocene through late Pleistocene Caloosahatchee, Bermont and Fort Thompson Formations in to a single lithostratigraphic entity, the Okeechobee formation (informal). In mapping the shelly sands and carbonates, a generalized grouping as Tertiary-Quaternary shell units (TQsu) was utilized. This is equivalent to the informal Okeechobee formation. The distribution of the Caloosahatchee and Fort Thompson Formation are shown on previous geologic maps by Cooke (1945), Vernon and Puri (1964) and Brooks (1982). The Nashua Formation occurs within the Pliocene - Pleistocene in northern Florida. However, it crops out or is near the surface is an area too small to be shown on a map of this scale. Lithologically these sediments are complex, varying from unconsolidated, variably calcareous and fossiliferous quartz sands to well indurated, sandy, fossiliferous limestones (both marine and freshwater). Clayey sands and sandy clays are present. These sediments form part of the surficial aquifer system
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.
Suwannee Limestone (Oligocene): Suwannee Limestone - Peninsular Lower Oligocene carbonates crop out on the northwestern, northeastern and southwestern flanks of the Ocala Platform. The Suwannee Limestone is absent from the eastern side of the Ocala Platform due to erosion, nondeposition or both, an area referred to as Orange Island (Bryan, 1991). The Suwannee Limestone, originally named by Cooke and Mansfield (1936), consists of a white to cream, poorly to well indurated, fossiliferous, vuggy to moldic limestone (grainstone and packstone). The dolomitized parts of the Suwannee Limestone are gray, tan, light brown to moderate brown, moderately to well indurated, finely to coarsely crystalline, dolostone with limited occurrences of fossiliferous (molds and casts) beds. Silicified limestone is common in Suwannee Limestone. Fossils present in the Suwannee Limestone include mollusks, foraminifers, corals and echinoids.
Suwannee Limestone- Marianna Limestone undifferentiated (Oligocene): Suwannee Limestone- Marianna Limestone undifferentiated - Undifferentiated Lower Oligocene Sediments - The undifferentiated Lower Oligocene sediments of the central panhandle consist of white to cream-colored, poorly to well indurated, variably fossiliferous limestones (grainstone, packstone, wackestone and mudstone). Glauconite occurs in some sediments. Siliciclastics form a minor component in some sediments. Thin beds of siliciclastics (Byram Marl and Buccatuna Formation) are included in the undifferentiated Lower Oligocene sediments. The Lower Oligocene carbonates form important parts of the upper FAS (Miller, 1986).
Tamiami Formation (Pliocene): Tamiami Formation - The Tamiami Formation (Mansfield, 1939) is a poorly defined lithostratigraphic unit containing a wide range of mixed carbonate-siliciclastic lithologies and associated faunas (Missimer, 1992). It occurs at or near the land surface in Charlotte, Lee, Hendry, Collier and Monroe Counties in the southern peninsula. A number of named and unnamed members are recognized within the Tamiami Formation. These include: the Buckingham Limestone Member; an unnamed tan clay and sand; an oyster (Hyotissa) facies, a sand facies, the Ochopee Limestone Member, the Bonita Springs Marl Member; an unnamed limestone facies; the Golden Gate Reef Member; and the Pinecrest Sand Member (Missimer, 1992). The individual members of the Tamiami Formation were not separately mapped on the geological map. Lithologies of the Tamiami Formation in the mapped area include: 1) light gray to tan, unconsolidated, fine to coarse grained, fossiliferous sand; 2) light gray to green, poorly consolidated, fossiliferous sandy clay to clayey sand; 3) light gray, poorly consolidated, very fine to medium grained, calcareous, fossiliferous sand; 4) white to light gray, poorly consolidated, sandy, fossiliferous limestone; and 5) white to light gray, moderately to well indurated, sandy, fossiliferous limestone. Phosphate is present in virtually all lithologies as limited quantities of sand- to gravel-sized grains. Fossils present in the Tamiami occur as molds, casts and original material. The fossils present include barnacles, mollusks, corals, echinoids, foraminifers and calcareous nannoplankton. The Tamiami Formation has highly permeable to impermeable lithologies that form a complex aquifer. Locally, it is part of the surficial aquifer system. In other areas, it forms a part of the intermediate confining unit/aquifer system.

Georgia

Bangor Limestone (Mississippian): Bangor Limestone
Charlton Formation and Duplin Marl (Pliocene): Charlton Formation and Duplin Marl
Chickamauga Group undivided (Ordovician): Chickamauga Group undivided
Chickamauga Group; Chota Formation (Ordovician): Chickamauga Group; Chota Formation
Chickamauga Group; Holston Limestone (Ordovician): Chickamauga Group; Holston Limestone
Chickamauga Group; Middle Ordovician rocks; Lenoir Limestone (Middle Ordovician): Chickamauga Group; Middle Ordovician rocks; Lenoir Limestone
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.
Chickamauga Group; Upper and Middle Ordovician rocks (Oum) includes Sequatchie Limestone, Murfreesboro Limestone, Ridley Limestone, Moccasin Limestone and Bays Formation. (Ordovician): Chickamauga Group; Upper and Middle Ordovician rocks (Oum) includes Sequatchie Limestone, Murfreesboro Limestone, Ridley Limestone, Moccasin Limestone and Bays Formation.
Clayton Formation (Paleocene): Clayton Formation
Conasauga Group; Maynardville Limestone (Cambrian): Conasauga Group; Maynardville Limestone
Conasauga Group; Middle unit; Limestone unit (Cambrian): Conasauga Group; Middle unit; Limestone unit: Includes limestone unit (Ccls), possible equivalent of Rutledge Limestone of Tennessee and shale unit (Cc), possible equivalent of Rogersville Shale of Tennessee
Conasauga Group; Middle unit; Shale unit (Cambrian): Conasauga Group; Middle unit; Shale unit: Includes limestone unit (Ccls), possible equivalent of Rutledge Limestone of Tennessee and shale unit (Cc), possible equivalent of Rogersville Shale of Tennessee
Conasauga Group; Upper unit; limestone and shale unit (Cambrian): Conasauga Group; Upper unit; limestone and shale unit: Includes limestone and shale unit (Ccsl). Possible equivalent of the Maryville Limestone and Nolichucky Shale of Tennessee with a dolostone member (Ccd).
Floyd Shale; unnamed limestone member (Mississippian): Floyd Shale; unnamed limestone member (Ml in Floyd County) at the base
Knox Group undifferentiated (Ordovician-Cambrian): Knox Group undifferentiated
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
Newala Limestone (Ordovician): Newala Limestone
Ocala Limestone (Eocene): Ocala Limestone, generally covered with Oligocene and Eocene residuum (Flint River Formation of Cooke, 1939); includes up-dip area, Tivola Limestone of Connell (1955). (*)- outcrops of Ocala Limestone on Dougherty Plain.
Ripley Formation (Cretaceous): Ripley Formation
Sandersville Limestone (Eocene): Sandersville Limestone (Es)
Suwannee Limestone and its residuum (Oligocene): Suwannee Limestone and its residuum, as mapped, includes Chattahoochee Limestone in Seminole and Decatur Cos.; Flint River Formation, in part, (Cooke, 1939); Jacksonboro Limestone in Screven Co.; and Glendon and Marianna Limestones in Pulaski Co.
Tallahatta Formation (Eocene): Tallahatta Formation

Iowa

Cedar Valley Limestone (Phanerozoic | Paleozoic | Devonian-Middle): Finely crystalline and clastic limestone in upper part with coral and stromatoporoid-rich zones; brown, dolomitic limestone with biostromes of corals and stromatoporoids in middle part; gray argillaceous, fossiliferous limestone in lower part; dominantly dolomite with intervals of gypsum in the subsurface of central and southwestern Iowa.
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.
Douglas Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Virgil]): Cyclic deposits with shale, siltstone and minor thin limestone beds; Lawrence Formation at top and Stranger Formation at base.
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
Kansas City Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Missouri]): Cyclic deposits with prominent limestone beds, shale; Bonner Springs Shale at top and Hertha Limestone at base.
Kinderhook Series (Phanerozoic | Paleozoic | Carboniferous Mississippian-Early): Gilmore City Limestone- light gray fossiliferous limestone, commonly oolitic. Approx thickness 155 ft. Hampton Formation- limestone and dolomite; fossiliferous gray chert in lower portion. Approx. thickness 150 ft. Starrs Cave Formation- bio-fragmental limestone; oolitic in part. Approx thickness 15 ft. Prospect Hill Formation- greenish-gray siltstone. Approx thickness 90 ft. McCraney Limestone- very pale orange to pale yellowish-brown sublithographic limestone and brown dolomite. Approx thickness 65 ft.
LaPort City Chert (Phanerozoic | Paleozoic | Devonian-Early): Predominantly chert with limestone and dolomite; minor shale and sandstone. Found in subsurface only.
Lansing Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Missouri]): Cyclic deposits with thin bedded limestones and interbedded red and green shales; Stranton Limestone at top, Vilsa Shale and Plattsburg Limestone at base.
Lime Creek Formation (Phanerozoic | Paleozoic | Devonian-Late): Fossiliferous limestone or dolomite in upper part with local stromatoporoid biostromes in north-central Iowa; extremely fossiliferous gray shale and argillaceous limestone in middle; gray shale in lower part with spore carps toward base.
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.
Shawnee Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Virgil]): Cyclic deposits with prominent limestone beds and thin shales; Topeka Formation at top and Oread Formation at base.
Shell Rock Formation (Phanerozoic | Paleozoic | Devonian-Late): Predominantly stromatoporoid biostromes in upper part; argillaceous limestone and gray shale in middle; massive limestone and dolomite in lower part with stromatoporoid biostromes near base; in north-central Iowa only.
State Quarry Limestone (Phanerozoic | Paleozoic | Devonian-Late): Fossiliferous limestone; may be time equivalent of at least the upper part of the Shell Rock Formation; in northern Johnson County only. Approx thickness ?ft
Wabaunsee Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Virgil]): Cyclic deposits, principally shale with limestone, siltstone, minor sandstone units and thin coal seams.
Wapsipinicon Formation (Phanerozoic | Paleozoic | Devonian-Middle): In descending order, finely crystalline limestone; brown dolomite with gypsum; gray, sandy shale and argillcceous limestone; and massive, finely crystalline, dolomitic limestone and pale-orange dolomite.

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, arenite, and chert: Devonian to Ordovician marine outer continental-shelf deposits; east-central Idaho (Devonian to Ordovician): Devonian to Ordovician marine calcareous sediments north of the Snake Plain.
Dolostone, limestone, arenite, chert, and conglomerate; Ordovician marine continental-shelf deposits; southeastern Idaho (Ordovician): Ordovician marine dolomite, quartzite, and limestone; subdivisions are (Ou and Ol).
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.
Dolostone, limestone, siltstone, arenite, and chert; Devonian and Silurian marine upper continental-slope deposits; east-central and central Idaho; (Devonian and Silurian): Devonian and Silurian shallow-water marine carbonate units of east-central 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, arenite, and shale; Cambrian marine continental-shelf deposits; northern Idaho (Middle Cambrian): Middle Cambrian thinly laminated claystone overlying coarse-grained pebbly quartzite of northern Idaho.
Limestone, arenite, dolostone, chert, siltstone, shale; Upper Paleozoic marine continental-shelf deposits; southeastern Idaho (Late Paleozoic): Upper Paleozoic marine sediments in southern Idaho.
Limestone, arenite, shale, dolostone, and siltstone; Upper Proterozoic to Cambrian marine continental-shelf deposits; southeastern Idaho (Cambrian): Cambrian marine dolomite, limestone, claystone, and quartzite; grades into Precambrian.
Limestone, dolostone, arenite, shale, and siltstone; Lower Paleozoic marine continental-shelf deposits; southeastern Idaho; (Early Paleozoic): Lower Paleozoic marine carbonate and clastic units southeast of the Snake Plain.
Limestone, dolostone, sandstone, siltstone, and chert; Lower Permian to Lower Pennsylvanian marine continental-shelf deposits; east-central Idaho (Early Permian to Early Pennsylvanian): Lower Permian to Lower Pennsylvanian (Carboniferous) shallow-water detritus.
Limestone, dolostone, shale, and arenite; Ordovician and Cambrian shallow marine inner continental-shelf deposits; southeastern Idaho (Ordovician and Cambrian): Ordovician, commonly Lower, and Cambrian marine sediments of eastern and southern 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.
Limestone, slate; Upper Triassic greenschist-facies metamorphic rocks; western Idaho, Blue Mountains island-arc complex; (Late Triassic): Upper Triassic shale overlying reefal limestone and dolomite in west-central 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.
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).

Illinois

Bond Formation (Pennsylvanian): Bond Formation
Carbondale Formation (Pennsylvanian): Carbondale Formation
Galena-Platteville Groups (Ordovician): Galena-Platteville Groups
Kinderhookian Series (Mississippian): Kinderhookian Series
Lower Chesterian (Glen Dean - Renault) Series (Mississippian): Lower Chersterian (Glen Dean - Renault) Series
Lower Devonian (Devonian): Lower Devonian
Lower Valmeyeran (Keokuk-Sedalia) Series (Mississippian): Lower Valmeyeran (Keokuk-Sedalia) Series
Maquoketa Group (Ordovician): Maquoketa Group
Middle Devonian (Devonian): Middle Devonian
Middle Valmeyeran (Salem, Warsaw, Borden, Springville; includes thin Mvl and Mk in south and east) Series (Mississippian): Middle Valmeyeran (Salem, Warsaw, Borden, Springville; includes thin Mvl and Mk in south and east) Series
Silurian (Silurian): Silurian
Upper Valmeyeran (Aux Vases, Ste. Genevieve, St. Louis) Series (Mississippian): Upper Valmeyeran (Aux Vases, Ste. Genevieve, St. Louis) Series

Indiana

Antrim Shale (Devonian): Antrim Shale - Black shale; gray shale and limestone in lower part
Bainbridge Group and Sexton Creek Limestone (Silurian): Bainbridge Group and Sexton Creek Limestone - Limestone and dolomite, in part cherty and argillaceous, shown in cross-section only
Black River and Ancell Groups (Ordovician): Black River and Ancell Groups - Dolomite, limestone, and sandstone
Blue River Group (Mississippian): Blue River Group - Mostly micritic, skeletal, and oolitic limestone
Borden Group (Mississippian): Borden Group - Mostly siltstone; lenses of crinodial limestone in upper part. Much cherty and silty limestone and dolomite in northwest. NP, top of New Providence Shale
Buffalo Wallow Group (Mississippian): Buffalo Wallow Group - Mostly shale and sandstone; also includes thin beds of micritic limestone. L, Leopold Limestone member
Dillsboro Formation (Ordovician): Dillsboro Formation - Skeletal limestone and calcareous shale
Knox Supergroup (Cambrian-Ordovician): Knox Supergroup - P, base of Prairie du Chien Group
Kope Formation (Ordovician): Kope Formation - Shale and thin skeletal limestone
Lexington Limestone (Ordovician): Lexington Limestone - Micritic and skeletal limestone
Louisville Limestone through Brassfield Limestone (Silurian): Louisville Limestone through Brassfield Limestone - Sexton Creek Limestone at base in Kentland area and on cross-section
Maquoketa Group (Ordovician): Maquoketa Group - Shale and limestone
Muscatatuck Group (Devonian): Muscatatuck Group - Limestone and dolomite
New Harmony Group (Devonian): New Harmony Group - Cherty limestone and dolomite, shown in cross-sections only
Ordovician rocks, undifferentiated (Silurian): Ordovician rocks, undifferentiated - Shale and limestone; upper part of Maquoketa Group in deep buried valleys; Maquoketa to upper part of Knox Supergroup in Kentland area
Pleasant Mills Formation (Silurian): Pleasant Mills Formation - Dolomite, limestone, and argillaceous dolomite
Salamonie Dolomite, Cataract Formation, and Brassfield Limestone (Silurian): Salamonie Dolomite, Cataract Formation, and Brassfield Limestone
Sanders Group (Mississippian): Sanders Group - Mostly skeletal limestone, cherty in lower part
Stephensport Group (Mississippian): Stephensport Group - Sandstone, micritic and skeletal limestone, and shale
Wabash Formation (Silurian): Wabash Formation - Limestone, dolomite, and argillaceous dolomite
West Baden Group (Mississippian): West Baden Group - Shale, sandstone, and micritic and skeletal limestone
Whitewater Formation (Ordovician): Whitewater Formation - Skeletal limestone and calcareous shale; dolomitic mudstone (S, Saluda Member) at base

Kansas

Admire Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late): Includes: Grenola Limestone, Roca Shale, Red Eagle Limestone (base RE), Johnson Shale, Foraker Limestone (base FO), Janesville Shale with Five Point Limestone Member (base FP), Falls City Limestone, and Onaga Shale.
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.
Chase Group (Phanerozoic | Paleozoic | Permian [Gearyan]): Nolans Limestone- upper and lower limestone seperated by shale, 40 ft thick. Odell Shale- mostly red and green shale, 40 ft. thick. Winfield Limestone (base WF)- cherty limestone with fossiliferous gray shale, 25 ft. thick. Doyle Shale- two shale members seperated limestone, 70 ft. thick. Barneston Limestone (base BA)- two thick limestone members seperated by thin limestone, 90 ft. thick: with Fort Riley Limestone Member( base FR)- gray to tan massive to thin bedded limestone with minor gray shale, 45 ft thick. Matfeild Shale- two varicolored shale members seperated by limestone, 80 ft. thick. Wreford Limestone- two cherty limestone members seperated shale, 40 ft. thick.
Council Grove Group (Phanerozoic | Paleozoic | Permian [Gearyan]): Includes: Speiser Shale, Funston Limestone, Blue Rapids Shale, Crouse Limestone (base CS), Easy Creek Shale, Bader Limestone (base BE), Stearns Shale, Beattie Limestone, Eskridge Shale, and Neva Limestone.
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.
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.
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 seperated 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.
Meramecian and Osagian Series: Warsaw Limestone and Keokuk Limestone (Phanerozoic | Paleozoic | Carboniferous Mississippian [Osagian]): Warsaw Limestone- semigranular limestone interlaminated with saccharoidal dolomite with large amounts of gray chert; glauconite occurrs in the lower part. Keokuk Limestone- white tripolitic, chert, siliceous limestone, and dolomite
Niobrara Chalk (Phanerozoic | Mesozoic | Cretaceous-Late): interbedded, soft, light-gray calcareous shale and chalk
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
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).
Sumner Group (Phanerozoic | Paleozoic | Permian [Cimarronian]): Ninnescah Shale (base N)- mostly red silty shale with some gray shale , argillaceous limestone and dolomite. Wellington FM with Carlton Limestone Member (base CR)-mostly gray and some red shale with minor limestone and dolomite, siltstone, gypsum and anhydrite
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

Ashlock Formation, Grant Lake and Calloway Creek Limestones, and Fairview Formation, undivided (Ordovician): Ashlock Formation, Grant Lake and Calloway Creek Limestones, and Fairview Formation, undivided
Bull Fork Formation (Ordovician): Bull Fork Formation
Bull Fork Formation and Grant Lake and Calloway Creek Limestones, undivided (Ordovician): Bull Fork Formation and Grant Lake and Calloway Creek Limestones, undivided; Along Ohio River in Oldham and Trimble Counties
Cumberland Formation and Leipers and Catheys (?) Limestones, undivided (Ordovician): Cumberland Formation and Leipers and Catheys (?) Limestones, undivided; in southernmost Kentucky
Drakes Formation (Ordovician): Drakes Formation
Drakes Formation and Grant Lake and Calloway Creek Limestones, undivided (Ordovician): Drakes Formation and Grant Lake and Calloway Creek Limestones, undivided; in Boyle, Casey, and Marion Counties
Garrard Siltstone and Kope and Clays Ferry Formations, undivided (Ordovician): Garrard Siltstone and Kope and Clays Ferry Formations, undivided
High Bridge Group (Ordovician): High Bridge Group
Lexington Limestone (Ordovician): Lexington Limestone
Limestone bodies in the Fort Payne Formation (Mississippian): Limestone bodies in the Fort Payne Formation; including Cane Valley Limestone Member
Louisville Limestone and Waldron Shale, undivided (Silurian): Louisville Limestone and Waldron Shale, undivided
Mauzy Formation (Lower Permian): Mauzy Formation
New Albany, Chattanooga, and Ohio Shales, Boyle Dolomite (Limestone), and Sellersburg Limestone, undivided (Devonian to Mississippian): New Albany, Chattanooga, and Ohio Shales, Boyle Dolomite (Limestone), and Sellersburg Limestone, undivided
Newman Limestone (Mississippian): Newman Limestone
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
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
Preachersville Member of Drakes Formation and Bull Fork Formation, undivided (Ordovician): Preachersville Member of Drakes Formation and Bull Fork Formation, undivided; in Bath and Montgomery Counties
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
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
Salem, Warsaw, and Harrodsburg Limestones, undivided (Mississippian): Salem, Warsaw, and Harrodsburg Limestones, undivided
Sellersburg and Jeffersonville Limestones, undivided (Lower to Middle Devonian): Sellersburg and Jeffersonville Limestones, undivided; in Jefferson and Oldham Counties
Ste. Genevieve and St. Louis Limestones, undivided (Mississippian): Ste. Genevieve and St. Louis Limestones, undivided; includes Salem Limestone west of Christian County
Warsaw Limestone (Mississippian): Warsaw Limestone; west of Christian County

Louisiana

Upper Cretaceous (Phanerozoic | Mesozoic | Cretaceous): fossiliferous limestone and marl

Massachusetts

Braintree Argillite and Weymouth Formation (Middle and Lower Cambrian): Braintree Argillite and Weymouth Formation - Argillite, some with rare limestone; contains Middle and Early Cambrian faunae respectively.
Hoppin Formation (Middle and Lower Cambrian): Hoppin Formation - Quartzite, argillite, and minor limestone; contains Middle Cambrian fauna.
Stockbridge Formation (Lower Ordovician): Stockbridge Formation - Local layers of punky weathering crossbedded quartzose limestone near base (Osf).
Stockbridge Formation (Lower Ordovician): Stockbridge Formation - Blue and gray mottled limestone and calcite marble and beds of beige dolostone.
Walloomsac Formation (Middle Ordovician): Walloomsac Formation - Dark-gray, graphitic quartz phyllite and schist containing minor lenses of limestone.
Walloomsac Formation (Middle Ordovician): Walloomsac Formation - Blue-gray and white mottled crystalline limestone lenses near base of the Walloomsac locally yielding fragments of pelmatozoa, bryozoa and cup coral.

Maryland

Chambersburg Limestone and St. Paul Group (including New Market Limestone and Row Park Limestone) (Ordovician ): Chambersburg Limestone - Dark gray, fine- to medium-grained, thin-bedded argillaceous limestone; nodular and fossiliferous; thickness 225 to 250 feet; and St. Paul Group, including New Market Limestone - Upper part gray, thick-bedded calcilutite; fossiliferous; lower part light gray, thin-bedded, laminated argillaceous calcilutite; thickness 285 feet in south, increases to 700 feet in north; and Row Park Limestone - Light gray, fine-grained, medium- to thick-bedded calcarenite; calcilutite, and dolomitic limestone; interbedded dark gray, cherty, granular limestone; thickness 100 feet in south, increases to 680 feet in north.
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.
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.
Elbrook Limestone (Cambrian): Elbrook Limestone - Light blue, laminated, argillaceous limestone and calcareous shale; some dolomite; thickness 1,400 to possibly 3,000 feet.
Frederick Limestone (Cambrian): Frederick Limestone - Blue, slabby, thin-bedded limestone and minor shale; contains Upper Cambrian (Trempealeauian) faunule; thickness approximately 480 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.
Grove Limestone (Upper Cambrian to Lower Ordovician ): Grove Limestone - Dark gray to light dove, thick-bedded limestone; dolomite beds in lower part; highly quartzose limestone at base; Upper Cambrian to Lower Ordovician in age; thickness approximately 590 feet.
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.
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.
Rockdale Run Formation (Ordovician): Rockdale Run Formation - Upper one-third gray, mottled, cherty dolomite and dolomitic limestone; lower two-thirds gray, cherty argillaceous calcarenite and algal limestone with interbedded dolomite and oolitic limestone; thickness at least 1,700 feet east of Conococheague Creek, increases to about 2,500 feet in west.
Silver Run Limestone (Late Precambrian (?)): Silver Run Limestone - Blue, thin-bedded, finely crystalline schistose limestone and calcareous slate.
Stonehenge Limestone (Ordovician): Stonehenge Limestone - Upper part gray, thin-bedded, coarse-grained to conglomeratic, oolitic calcarenite; some dolomite; lower part gray, thick-bedded, fine-grained algal limestone; thickness 500 to 800 feet.
Tomstown Dolomite (Cambrian): Tomstown Dolomite - Interbedded light gray to yellowish-gray, thin- to thick-bedded dolomite and limestone; some shale layers; gradational contact with Antietam; thickness 200 to 1,000 feet.
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.

Maine

Devonian - Ordovician Bucksport Formation (Devonian - Ordovician): Devonian - Ordovician Bucksport Formation
Devonian - Silurian Rindgemere Formation lower member (Devonian - Silurian): Devonian - Silurian Rindgemere Formation lower member
Devonian - Silurian Rindgemere Formation lower member limestone (Devonian - Silurian): Devonian - Silurian Rindgemere Formation lower member limestone
Devonian Beck Pond Limestone (Devonian): Devonian Beck Pond Limestone
Devonian Parker Bog Formation (Devonian): Devonian Parker Bog Formation
Devonian Seboomook Formation Day Mountain member limestone (Devonian): Devonian Seboomook Formation Day Mountain member limestone
Devonian Tarratine Formation McKenny Pond Limestone (Devonian): Devonian Tarratine Formation McKenny Pond Limestone
Megunticook Formation, Limestone Member (Ordovician - Cambrian): Megunticook Formation, Limestone Member
Ordovician - Cambrian Chase Brook Formation (Ordovician - Cambrian): Ordovician - Cambrian Chase Brook Formation
Ordovician - Precambrian Z Cushing Formation limestone (Ordovician - Precambrian Z): Ordovician - Precambrian Z Cushing Formation limestone
Ordovician - Precambrian Z Spurwink Limestone (Ordovician - Precambrian Z): Ordovician - Precambrian Z Spurwink Limestone
Ordovician unnamed sandstone (Ordovician): Ordovician unnamed sandstone
Precambrian Z rocks of Islesboro limestone (Precambrian): Precambrian Z rocks of Islesboro limestone
Silurian - Ordovician Carys Mills Formation (Silurian - Ordovician): Silurian - Ordovician Carys Mills Formation
Silurian Ames Knob formation (Silurian): Silurian Ames Knob formation
Silurian Spragueville Formation (Silurian): Silurian Spragueville Formation
Silurian rocks of the Fivemile Brook sequence (Silurian): Silurian rocks of the Fivemile Brook sequence
Silurian unnamed limestone (Silurian): Silurian unnamed limestone

Michigan

Antrim Shale (Late Devonian): Antrim Shale
Bayport Limestone (Mississippian): Bayport Limestone
Bell Shale (Middle Devonian): Bell Shale
Big Hill Dolomite (Late Ordovician): Big Hill Dolomite
Black River Limestone (Late Ordovician): Black River Limestone
Bois Blanc Formation (Early Devonian): Bois Blanc Formation
Burnt Bluff Formation (Early Silurian): Burnt Bluff Formation
Cataract Formation (Early Silurian): Cataract Formation
Coldwater Shale (Mississippian): Coldwater Shale
Collingwood Limestone (Late Ordovician): Collingwood Limestone
Detroit River Group (Middle Devonian): Detroit River Group
Dundee Limestone (Middle Devonian): Dundee Limestone
Garden Island Formation (Early Devonian): Garden Island Formation
Mackinac Breccia (Early Devonian): Mackinac Breccia
Manistique Formation (Early Silurian): Manistique Formation
Paleozoic undivided (Paleozoic): Paleozoic undivided
Stonington Formation (Late Ordovician): Stonington Formation
Traverse Group (Middle Devonian): Traverse Group
Trenton Limestone (Late Ordovician): Trenton Limestone

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
Decorah Shale (Middle Ordovician) (Middle Ordovician): Decorah Shale (Middle Ordovician) - Light-greenish-gray shale and lesser amounts of coquinoid limestone, especially in the upper half of the formation. Mapped as a separate unit where possible.
Devonian rocks, undivided (Devonian): Devonian rocks, undivided - Limestone, dolomitic limestone, and dolostone of the Cedar Valley and Wapsipinicon Groups
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
Lithograph City Formation, Coralville Formation and Hinckle and Eagle City Members of the Little Cedar Formation (Cedar Valley Group), undivided (Devonian): Lithograph City Formation, Coralville Formation and Hinckle and Eagle City Members of the Little Cedar Formation (Cedar Valley Group), undivided - Limestone, dolostone, and lesser amounts of shale
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 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
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
Upper and Middle Ordovician rocks, undivided (Late and Middle Ordovician): Upper and Middle Ordovician rocks, undivided - Limestone and shaly limestone of the Maquoketa and Dubuque Formations, and limestone and dolostone of the Galena Group in the Hollandale embayment of southeastern Minnesota

Missouri

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
DECORAH GROUP, PLATTIN GROUP (Phanerozoic | Paleozoic | Ordovician-Middle [Mohawkian]): DECORAH GROUP, PLATTIN GROUP
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
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
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
MERAMECIAN SERIES (Phanerozoic | Paleozoic | Carboniferous Mississippian-Late [Meramecian]): MERAMECIAN SERIES - ST. LOUIS LIMESTONE, SALEM FORMATION, WARSAW FORMATION
OSAGEAN SERIES (Phanerozoic | Paleozoic | Carboniferous Mississippian-Early [Osagean]): OSAGEAN SERIES - KEOKUK LIMESTONE, BURLINGTON LIMESTONE, ELSEY FORMATION, REEDS SPRING FORMATION, PIERSON LIMESTONE, FERN GLEN FORMATION
PENNSYLVANIAN UNDIFFERENTIATED (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian): PENNSYLVANIAN UNDIFFERENTIATED
SHAWNEE GROUP (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Upper Virgilian]): SHAWNEE GROUP - cyclic deposits, limestone and shale with sandstone and siltstone.
SILURIAN SYSTEM (Phanerozoic | Paleozoic | Silurian-Early Silurian-Middle(?) Silurian-Late): SILURIAN SYSTEM - JOLIET LIMESTONE, BOWLING GREEN DOLOMITE, BRYANT KNOB FORMATION, BAINBRIDGE FORMATION, SEXTON CREEK LIMESTONE
ST. PETER SANDSTONE, EVERTON FORMATION (Phanerozoic | Paleozoic | Ordovician-Early Ordovician-Middle): ST. PETER SANDSTONE, EVERTON FORMATION
UNDIFFERENTIATED (Phanerozoic | Paleozoic | Ordovician): UNDIFFERENTIATED (ORDOVICIAN ROCKS)

Mississippi

Chester group (Mississippian): Chester group - Sandstone, shale, and limestone.
Chester group (Devonian): Chester group - Chattanooga shale (Carboniferous or Devonian) and underlying limestones of Early Devonian age.
Chester group (Mississippian): Chester group - Limestone, chert, and shale of Meramec, Osage, and Kinderhook age.
Clayton formation (Paleocene): Clayton formation - (Midway group), Upper part, greenish-gray coarsely glauconitic sandy clay and marl; lower part, crystalline sandy limestone and loose sand, represented south of Houston by a discontinuous bed of indurated calcareous sandstone.
Cook Mountain formation (Eocene): Cook Mountain formation - (Claiborne group), Southeast of Pearl River, marl, limestone, glauconitic sand, and chocolate-colored clay; northwest of Pearl River, predominantly chocolate-colored clay with some glauconitic sand.
Mooreville chalk (Arcola limestone member) (Upper Cretaceous): Mooreville chalk (Arcola limestone member) - (Selma group), Arcola limestone member at top, hard bluff-colored limestone.
Vicksburg group and Chickasawhay limestone (Oligocene): Vicksburg group and Chickasawhay limestone - Chickasawhay limestone, sandy limestone, and sand, present only in eastern MS (mapped with it is the overlying Paynes Hammock sand of Miocene age); Vicksburg group, predominantly limestone and marl, but contains some bentonite and near the top, chocolate-colored clay and some sand.

Montana

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.
Greenhorn formation (Phanerozoic | Mesozoic | Cretaceous-Late): Greenhorn formation: mainly light-gray marl and calcareous shale.
Greyson shale (Proterozoic | Mesoproterozoic): Greyson shale: dark-gray to dark-brown argillaceous and sandy rock; weathers brown or red; grades into the Spokane above and the Newland below. Distinguished only in the general vicinity of Helena.
Jurassic and Triassic rocks, undifferentiated (Phanerozoic | Mesozoic | Triassic Jurassic): Jurassic and Triassic rocks, undifferentiated: in east-central Madison County where scale did not permit differentiation on map.
Jurassic, undifferentiated (Phanerozoic | Mesozoic | Jurassic): Jurassic, undifferentiated: calcareous shale and sandstone; includes the Morrison formation, the Ellis group, Sundance formation, and other rocks of Jurassic age.
Kootenai formation and associated rocks (Phanerozoic | Mesozoic | Jurassic Cretaceous-Early): Kootenai formation and associated rocks: conglomerate, sandstone, shale, and mudstone; purplish and green beds are common; mainly the Kootenai; in southern Montana includes strata that have been mapped as Cloverly formation. Includes Second Cat Creek and Third Cat Creek sands of drillers in central part of State; Sunburst sand of drillers in north-central part; and Cut Bank sand of drillers in western part. As here mapped, may locally include thin units of Jurassic age.
Spokane shale (Proterozoic | Mesoproterozoic): Spokane shale: red or red-purple shale with numerous green beds locally and some quartzite; grades into the Empire above and the Greyson below and in some areas as mapped probably includes all or part of Empire and Greyson shales. The name has been used over a wide area in Montana, but in a strict sense can be used safely only in the general vicinity of Helena.
St. Mary River formation (Phanerozoic | Mesozoic | Cretaceous-Late): St. Mary River formation: Greenish-gray clay with local nodular limestone and crossbedded sandstone.
Triassic, undifferentiated (Phanerozoic | Mesozoic | Triassic): Triassic, undifferentiated: conglomerate, sandstone, shale, and impure limestone belonging to the Dinwoody and Thaynes formations and other units of Triassic age, and the Chugwater of Triassic and Permian age.
White River formation (Phanerozoic | Cenozoic | Tertiary): White River formation: Light-colored clay with minor beds of sandstone and local beds of nodular limestone.

North Carolina

Castle Hayne Formation; Comfort Member and New Hanover Member, undivided (Tertiary): Comfort Member and New Hanover Member, undivided - Comfort Member: bryozoan-echinoid skeletal limestone, locally dolomitized, solution cavities common. New Hanover Member: phosphate-pebble conglomerate, micritic, thin; restricted to basal part of Castle Hayne Formation in southeastern counties.
Castle Hayne Formation; Spring Garden Member (Tertiary): Spring Garden Member - molluscan-mold limestone, indurated, very sandy. Grades downward into a calcareous sand and laterally into Comfort Member.
Peedee Formation (Cretaceous): Peedee Formation - sand, clayey sand, and clay, greenish gray to olive black, massive, glauconitic, locally fossiliferous and calcareous. Patches of sandy molluscan-mold limestone in upper part.
River Bend Formation (Tertiary): River Bend Formation - limestone, calcarenite overlain by and intercalated with indurated, sandy, molluscan-mold limestone.
Yorktown Formation and Duplin Formation, Undivided (Tertiary): Yorktown Formation and Duplin Formation, Undivided - Yorktown Formation: fossiliferous clay with varying amounts of fine-grained sand, bluish gray, shell material commonly concentrated in lenses; mainly in area north of Neuse River. Duplin Formation: shelly, medium- to coarse-grained sand, sandy marl, and limestone, bluish gray; mainly in area south of Neuse River.

North Dakota

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.
Chase Group (Phanerozoic | Paleozoic | Permian): Limestone and shale. Limestone is light gray to dark gray, yellowish gray to pale yellowish brown. Two limestones in the upper part are thin bedded to medium bedded, argillaceous, cherty and fossiliferous; two limestones in the lower part are medium to massive bedded, very cherty, and fossiliferous. Shale is gray, green, red, redish brown, calcareous, arenaceous, fossiliferous; locally fissile. Approx. max thickness 300 ft.
Council Grove Group (Phanerozoic | Paleozoic | Permian): Shale and interbedded limestone. Shale is gray, green, red, reddish brown, or maroon, sandy, calcareous, fossiliferous, locally fissile; several fissile black shale beds are in lower 75 feet. Interbedded dark- to light-gray, medium- to thick-bedded, argillaceous, cherty limestone beds are very fossiliferous and locally contain shale partings. Approx. max thickness 300 ft
Douglas Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Virgilian]): Shale and limestone. Shale is dark gray to medium gray, red , black, fossiliferous, calcareous and locally sandy. Limestone is dark gray to light gray, thin bedded to thick bedded, fossiliferous and locally sandy. Approx. max thickness 100 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.
Kansas City Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Missourian]): Limestone and shale. Limestone is dark gray to light gray, brownish gray, very thin bedded to massive, argillaceous, fossiliferous; contains very thin layers of chert, pyrite crystals, and small flakes of mica near base. Shale is dark gray to light gray, greenish gray, red, and black; locally slighty sandy, calcareous, carbonaeous, fissile, and fossiliferous. Approx. max thickness 200 ft
Lansing Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Missourian]): Limestone and shale. Limestone is dark gray to light gray, very thin bedded to massive, sandy fossiliferous, and cherty. Shale is dark gray to light gray, maroon, black, fossiliferous, and calcareous. Approx. max thickness 75 ft
Marmaton Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Desmoinesian]): Shale and limestone. Shale is dark gray to light gray, greenish gray, black, red, silty, sandy carbonaceous, fissile, calcareous; contains scattered limestone nodules. Limestone is medium gray to light gray, red, mottled thin bedded to thick bedded, sandy, shaly, vuggy, fossiliferous. Approx. max thickness 125 ft
Niobrara Formation (Phanerozoic | Mesozoic | Cretaceous-Late): Argillaceous chalk, limestone and shale. Chalk is medium gray to white, interbedded with thin layers of chalky shale; contains many fossil clams, oysters, and formanifera. Limestone is light gray to medium gray and yellowish gray, interbedded with medium-gray chalky shale; also contains fossil clams, oysters, and formanifera. Bedding plans commonly marked by thin layers of gypsum and locally a thin bed of red flint occurs at top of unit. Approx. max thickness 570 ft.
Shawnee Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Virgilian]): Limestone, shale and siltstone. Limestone is dark gray to very light gray, yellowish gray, very thin bedded to massive bedded, and fossiliferous; locally the thin bedds are argillaceous other beds are oolitic and a few contain chert. Shale is medium gray, greenish gray, pale red, dark redish brown, black, sandy fossiliferous and calcareous; black shale in part is fissile. Siltstone is light gray to greenish yellow, massive, calcareous; locally sandy. Approx. max thickness 200 ft

New Jersey

Beekmantown Group, Lower Part (Lower Ordovician): Beekmantown Group, Lower Part (Clarke and Schuchert, 1899) - Very thin to thick-bedded, interbedded dolomite and minor limestone. Upper beds are light-olive-gray to dark-gray, fine- to medium-grained, thin- to thick-bedded dolomite. Middle part is olivegray-, light-brown-, or dark-yellowish-orange- weathering, dark-gray, aphanitic to fine-grained, laminated to medium-bedded dolomite and light-gray to light-bluish-gray-weathering, medium-dark- to dark-gray, fine-grained, thin- to medium-bedded limestone, that is characterized by mottling with reticulate dolomite and light-olive-gray to grayish-orange, dolomitic shale laminae surrounding limestone lenses. Limestone grades laterally and down section into medium- gray, fine-grained dolomite. Lower beds consist of medium-light- to dark-gray, aphanitic to coarse-grained, laminated to medium-bedded, locally slightly fetid dolomite having thin black chert beds, quartz-sand laminae, and oolites. Lenses of light-gray, very coarse to coarse-grained dolomite and floating quartz sand grains and quartz-sand stringers at base of sequence. Lower contact placed at top of distinctive medium-gray quartzite. Contains conodonts of Cordylodus proavus to Rossodus manitouensis zones of North American Midcontinent province as used by Sweet and Bergstrom (1986). Unit Obl forms Stonehenge Formation of Drake and Lyttle (1985) and Drake and others (1985), upper and middle beds are included in Epler Formation, and lower beds are in Rickenbach Dolomite of Markewicz and Dalton (1977). Unit is about 183 m (600 ft) thick.
Beekmantown Group, Upper Part (Lower Ordovician): Beekmantown Group, Upper Part (Clarke and Schuchert, 1899) - Locally preserved upper beds are light- to medium-gray- to yellowish-gray-weathering, medium-light- to medium-gray, aphanitic to medium-grained, thin- to thick-bedded, locally laminated, slightly fetid dolomite. Medium-dark to dark-gray, fine-grained, medium-bedded, sparsely fossiliferous limestone lenses occur locally. Lower beds are medium-dark- to dark-gray, medium- to coarse-grained, mottled surface weathering, medium- to thick-bedded, strongly fetid dolomite that contains pods and lenses of dark-gray to black chert. Cauliflower-textured black chert beds of variable thickness occur locally. Gradational lower contact is placed at top of laminated to thin-bedded dolomite of the lower part (Obl) of the Beekmantown Group. Contains conodonts high in the Rossodus manitouensis zone to low zone D of the North American midcontinent province as used by Sweet and Bergstrom (1986). Upper beds are included in Epler Formation; lower beds are included in Rickenbach Dolomite of Drake and Lyttle (1985) and Drake and others (1985); entire upper part (Obu) is Ontelaunee Formation of Markewicz and Dalton (1977). Thickness ranges from 0 to 244 m (0-800 ft).
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.
Bossardville Limestone (Upper Silurian): Bossardville Limestone (White, 1882) - Light-gray to yellowish- gray-weathering, medium-gray to medium-dark-gray, very fine grained, locally fossiliferous, laminated to thin-bedded limestone and argillaceous limestone. Desiccation polygons occur in southwest. Lower contact is gradational and placed at top of uppermost dolomite. Thickness approximately 30 m (100 ft) in southwest, thinning to 3.1 m (10 ft) at New Jersey-New York State boundary.
Buttermilk Falls Limestone and Onondaga Limestones, undivided (Middle Devonian): Buttermilk Falls Limestone and Onondaga Limestones, undivided - Buttermilk Falls Limestone in southwestern part of outcrop belt grades into Onondaga Limestone along strike to northeast. The transition occurs north of Millville. Buttermilk Falls Limestone (Middle Devonian) (Willard, 1938) - Light- to medium-light-gray-weathering, medium- to dark-gray, thin- to medium-bedded, fossiliferous, flaggy, clayey to silty limestone and nodular black chert. Lower contact grades downward through several meters (feet) of silty limestone to interbedded limestone and calcareous siltstone of the Schoharie Formation. Thickness is approximately 82 m (270 ft). Onondaga Limestone (Middle Devonian) (Vanuxem 1840) - Light-medium-gray- weathering, medium gray, fine-grained, thin- to thick-bedded fossiliferous limestone. Black chert more abundant in upper half of unit. Lower contact grades into interbedded limestone and calcareous siltstone of the Schoharie Formation. Thickness approximately 60 m (200ft).
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).
Jacksonburg Limestone (Middle Ordovician): Jacksonburg Limestone (Kummel, 1908; Miller, 1937) - Upper part is medium- to dark-gray, laminated to thin-bedded shaly limestone and less abundant medium-gray arenaceous limestone containing quartz-sand lenses. Upper part thin to absent to northeast. Lower part is interbedded medium- to dark-gray, fine- to medium-grained, very thin to medium-bedded fossiliferous limestone and minor medium- to thick-bedded dolomite-cobble conglomerate having a limestone matrix. Unconformable on Beekmantown Group and conformable on the discontinuous sequence at Wantage in the Paulins Kill area. Contains conodonts of North American midcontinent province from Phragmodus undatus to Aphelognathus shatzeri zones of Sweet and Bergstrom (1986). Thickness ranges from 41 to 244m (135-800 ft).
Jacksonburg Limestone and Sequence at Wantage, undivided (Middle Ordovician): Jacksonburg Limestone and Sequence at Wantage, undivided - Jacksonburg Limestone - Upper part is medium- to dark-gray, laminated to thin-bedded shaly limestone and less abundant medium-gray arenaceous limestone containing quartz-sand lenses. Upper part thin to absent to northeast. Lower part is interbedded medium- to dark-gray, fine- to medium-grained, very thin to medium-bedded fossiliferous limestone and minor medium- to thick-bedded dolomite-cobble conglomerate having a limestone matrix. Unconformable on Beekmantown Group and conformable on the discontinuous sequence at Wantage in the Paulins Kill area. Contains conodonts of North American midcontinent province from Phragmodus undatus to Aphelognathus shatzeri zones of Sweet and Bergstrom (1986). Thickness ranges from 41 to 244m (135-800 ft). Sequence at Wantage - Restricted, discontinuous sequence of interbedded limestone, dolomite, conglomerate, siltstone, and shale. Upper part is medium-yellowish-brown- to olive-gray-weathering, medium- to dark-gray, very fine to fine-grained, laminated to massive limestone and dolomite that grade down into underlying clastic rocks of lower part. Upper part locally absent. Lower part ranges from grayish-red, medium-gray, pale-brown, and greenish-gray to pale-green mudstone and siltstone containing disseminated subangular to subrounded chert-gravel, quartz-sand lenses, and chert-pebble conglomerate. Lower contact unconformable. Thickness ranges from 0 to 46 m (0-150 ft).
Minisink Limestone and New Scotland Formation, undivided (Lower Devonian): Minisink Limestone and New Scotland Formation, undivided - Minisink Limestone (Epstein and others, 1967) - Light-medium-gray-weathering, medium-gray, fine-grained, medium-bedded, partly massive, argillaceous fossiliferous limestone. Some nodules and lenses of purer limestone occur locally. Lower contact gradational. Thickness uniformly 7 m (23 ft). New Scotland Formation (Clarke and Schuchert, 1899) - Upper part is dark-gray, very fine grained, laminated to thin-bedded siliceous shale containing pods of medium-dark-gray, very fine grained limestone; scattered thin beds and lenses of medium-gray, fine-grained argillaceous fossiliferous limestone; and small dark-gray chert nodules. Lower part is medium-dark-gray, thin-bedded, siliceous, fossiliferous calcareous shale. Contains thin beds and lenses of medium-gray, fine-grained, highly fossiliferous, argillaceous limestone containing nodules, lenses and, locally, irregular beds of dark-gray chert. Lower contact abrupt and placed at top of calcareous quartz sandstone. Total thickness is approximately 23 m (75 ft).
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 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.
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.
Schoharie Formation (Lower Devonian): Schoharie Formation (Vanuxem, 1840) - Yellowish-gray- to locally pale-olive-weathering, medium- to dark-gray, medium- to thick-bedded, calcaeous siltstone and lesser amounts of silty limestone. Locally contains thin ribs or pods of black chert in limestone. Limestone content decreases in lower part of unit. Contains the trace fossil Taonurus, a grazing trail. Lower contact gradational and placed at top of highest massive siltstone below lowest limestone. Thickness approximately 53 m (175 ft).
Wantage Sequence (Middle Ordovician): Wantage Sequence (Monteverde and Herman, 1989) - Restricted, discontinuous sequence of interbedded limestone, dolomite, conglomerate, siltstone, and shale. Upper part is medium-yellowish-brown- to olive-gray-weathering, medium- to dark-gray, very fine to fine-grained, laminated to massive limestone and dolomite that grade down into underlying clastic rocks of lower part. Upper part locally absent. Lower part ranges from grayish-red, medium-gray, pale-brown, and greenish-gray to pale-green mudstone and siltstone containing disseminated subangular to subrounded chert-gravel, quartz-sand lenses, and chert-pebble conglomerate. Lower contact unconformable. Thickness ranges from 0 to 46 m (0-150 ft).

New Mexico

Bell Canyon Formation (Phanerozoic | Paleozoic | Permian): Bell Canyon Formation; basin facies-sandstone, limestone, and shale; Guadalupian
Castile Formation (Phanerozoic | Paleozoic | Permian): Castile Formation; dominantly anhydrite sequence; Upper Permian
Cherry Canyon Formation (Phanerozoic | Paleozoic | Permian): Cherry Canyon Formation; basin facies-sandstone, limestone, and shale
Cutler Formation (Phanerozoic | Paleozoic | Permian): Cutler Formation; used in northern areas and Chama embayment only
Fort Hayes Limestone Member of Niobrara Formation (Phanerozoic | Mesozoic | Cretaceous): Fort Hays Limestone Member of Niobrara Formation
Graneros Shale and Greenhorn Formation (Phanerozoic | Mesozoic | Cretaceous): Graneros Shale and Greenhorn Formation; limited to northeastern area; lower Turonian and Cenomanian
Greenhorn Formation (Phanerozoic | Mesozoic | Cretaceous): Greenhorn Formation; limited to northeastern area. The Upper member (Bridge Creek Limestone) can be traced into western area where it is commonly shown as a bed-rank unit in Mancos Shale on detailed maps
Greenhorn Formation and Carlile Shale (Phanerozoic | Mesozoic | Cretaceous): Greenhorn Formation and Carlile Shale, undivided; locally includes Graneros Shale
Hueco Formation (Phanerozoic | Paleozoic | Permian): Hueco Formation; limestone unit restricted to south-central area; Pendejo Tongue divides Abo Formation into upper and lower parts; Wolfcampian
Lead Camp Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian): Lead Camp Formation; San Andres and Organ Mountains
Lewis Shale (Phanerozoic | Mesozoic | Cretaceous): Lewis Shale; marine shale and mudstone
Madera Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian): Madera Formation (Limestone, or Group); in Manzano Mountains includes Los Moyos Limestone and Wild Cow Formation; in Lucero Mesa includes Gray Mesa, Atrasdo, and Red Tanks Members; in Sacramento Mountains includes Beeman and Holder Formations; may include strata lumped as Magdalena Group in a few areas
Madera Limestone, exotic blocks (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian): Madera Limestone, exotic blocks; present only in the Chloride area of Sierra County
Menefee Formation (Phanerozoic | Mesozoic | Cretaceous): Menefee Formation; mudstone, shale, and sandstone; coal-bearing
Mississippian rocks, undivided (Phanerozoic | Paleozoic | Carboniferous Mississippian): Mississippian rocks, undivided; Arroyo Penasco Group in Sangre de Cristo Mountains, Sierra Nacimiento, San Pedro Mountain, and Sandia Mountains; Lake Valley Limestone in south-central New Mexico
Morrison Formation (Phanerozoic | Mesozoic | Jurassic): Morrison Formation; Upper Jurassic nonmarine rocks present only in northern one-third of state
Morrison Formation and upper San Rafael Group (Phanerozoic | Mesozoic | Jurassic): Morrison Formation and upper San Rafael Group
Panther Seep Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian): Panther Seep Formation; Organ, Franklin, and San Andres Mountains
Percha Shale (Phanerozoic | Paleozoic | Devonian): Percha Shale; southern Caballo Mountains; includes the Onate and Sly Gap Formations
Pierre Shale and Niobrara Formation (Phanerozoic | Mesozoic | Cretaceous): Pierre Shale and Niobrara Formation
Redonda Formation of Chinle Group (Phanerozoic | Mesozoic | Triassic): Redonda Formation
Rio Salado Tongue of Mancos Shale (Phanerozoic | Mesozoic | Cretaceous): Rio Salado Tongue of the Mancos Shale. Overlies Twowells Tongue of Dakota Sandstone; mapped only where Tres Hermanos Formation or the Atarque Sandstone is present; mapped as Kdr in parts of Socorro County; Turonian
Sangre de Cristo Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian Permian): Sangre de Cristo Formation, in Sangre de Cristo Mountains
Trujillo Formation of Chinle Group (Phanerozoic | Mesozoic | Triassic): Trujillo Formation; Norian
Victoria Peak Limestone (Phanerozoic | Paleozoic | Permian): Victorio Peak Limestone; in Brokeoff Mountains only
Yesa Formation (Phanerozoic | Paleozoic | Permian): Yeso Formation; sandstones, siltstones, anhydrite, gypsum, halite, and dolomite; Leonardian
intertongued Dakota-Mancos sequence (Phanerozoic | Mesozoic | Cretaceous): Intertongued Dakota-Mancos sequence of west-central New Mexico; includes the Whitewater Arroyo Tongue of Mancos Shale and the Twowells Tongue of the Dakota
travertine (Phanerozoic | Cenozoic | Tertiary Quaternary): Travertine
undivided, Upper Cretaceous (Phanerozoic | Mesozoic | Cretaceous): Upper Cretaceous, undivided. Includes Virden Formation in northern Hidalgo County, Ringbone Formation in Hidalgo and Luna and Grant Counties, and locally Beartooth and Sarten, Mancos in Silver City area; Cenomanian - Maastrichtian for most part, although Beartooth is pre-Cenomanian
upper Chinle Group (Garita Creek, Trujillo, Bull Canyon, and Redonda Formations) (Phanerozoic | Mesozoic | Triassic): Upper Chinle Group, Garita Creek through Redonda Formations, undivided

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
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
Dolomite (Silurian to Early Devonian): DOLOMITE-Includes units such as Laketown and Lone Mountain Dolomites. Locally includes rocks of Early Devonian age at top.
Dolomite and limestone (Middle Cambrian to Ordovician): DOLOMITE AND LIMESTONE-Undivided Cambrian and Ordovician rocks in part of Clark County; mostly Cambrian.
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.
Horse Spring Formation (Late Oligocene to Middle Miocene): HORSE SPRING FORMATION-Tuffaceous sedimentary rocks, southern Nevada
Limestone (Pennsylvanian): LIMESTONE-Includes Ely Limestone (mostly Lower and Middle Pennsylvanian)
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, cherty limestone, sandy limestone, and chert-pebble conglomerate (Pennsylvanian): LIMESTONE, CHERTY LIMESTONE, SANDY LIMESTONE, AND CHERT-PEBBLE CONGLOMERATE (Lower and Middle Pennsylvanian)-Includes units such as Moleen and Tomera Formations of Dott (1955)
Limestone, dolomite, and shale (Mississippian to Permian): LIMESTONE, DOLOMITE, AND SHALE (Upper Paleozoic)-Includes Van Duzer Limestone of Decker (1962)
Limestone, dolomite, shale, and quartzite (Ordovician): LIMESTONE, DOLOMITE, SHALE, AND QUARTZITE-Includes units such as Pogonip Group, Eureka Quartzite, and Ely Springs Dolomite. Where Ely Springs Dolomite or equivalent rocks are included in SOc unit, this unit includes only the Pogonip Group and Eureka Quartzite or their equivalents.
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
Platy limestone and limy siltstone, chert at base (Silurian to Early Devonian): PLATY LIMESTONE AND LIMY SILTSTONE, CHERT AT BASE-Includes units such as Roberts Mountains Formation, and Storff Formation and Chellis Limestone of Decker (1962). Locally includes rocks of Early Devonian age at top.
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)
Shale and thin-bedded or laminated limestone; also thinly interbedded limestone and chert (Middle Cambrian to Late Cambrian): SHALE AND THIN-BEDDED OR LAMINATED LIMESTONE; ALSO THINLY INTERBEDDED LIMESTONE AND CHERT-Includes units such as Preble and Emigrant Formations
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
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.
Silty limestone, minor amounts of shale, and some greenstone (Permian to Early Triassic): SILTY LIMESTONE, MINOR AMOUNTS OF SHALE, AND SOME GREENSTONE-Unnamed sequence in Adobe Range, northern Elko County
Tuffaceous sedimentary rocks (Late Eocene to Late Miocene): TUFFACEOUS SEDIMENTARY ROCKS-Locally includes minor amounts of tuff
Wyman Formation (Late Proterozoic): WYMAN FORMATION-Phyllite and phyllitic siltstone and minor amounts of limestone, dolomite, and sandstone

New York

Balmville Limestone (Middle Ordovician): Balmville Limestone - Vermont: Whipple Limestone.
Balmville Limestone (Middle Ordovician): Balmville Limestone
Beekmantown Group (Cambrian): Beekmantown Group - Mohawk Valley: Little Falls Dolostone-chert; Hoyt Formation-limestone, dolostone, oolite. Washington county: Whitehall Formation-dolostone, limestone; Ticonderoga Dolostone-chert.
Beekmantown Group (Lower Ordovician): Beekmantown Group - Mohawk Valley: Chuctanunda Creek Dolostone; Tribes Hill Formation-limestone, dolostaone; Gailor Dolostone. Washington County: Providence Island Dolostone; Fort Cassin Formation-limestone, dolostone; Fort Ann Formation-limestone, dolostone; Cutting Formation-dolostone, local chert, limestone at top, siltstone at base.
Beekmantown Group (in part) (Lower Ordovician): Beekmantown Group (in part) - In St. Lawrence Valley: Ogdensburg Dolostone (Beauharnois Dolostone in Canada); In Champlain Valley: Providence Island Dolostone; Fort Cassin Formation-limestone, dolostone; Fort Ann Formation (Spellman of Clinton and Essex Counties)-limestone, dolostone; Cutting Formation-dolostone (locally cherty), limestone, siltstone. In Vermont: includes Bridport, Bascom, Cutting, and Shelburne carbonates.
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.
Black River Group (Middle Ordovician): Black River Group - In Black River Valley: Chaumont Limestone-locally cherty; Lowville Limestone; Pamelia Formation-dolostone, shale, arkose. In Champlain Valley: Amsterdam, Isle La Motte, and Lowville Limestones: Pamelia Dolostone.
Black River Group (Middle Ordovician): Black River Group - Chaumont Limestone-chert; Lowville Limestone; Pamelia Dolostone.
Clinton Group (Lower Silurian): Decew Dolostone, Rochester Shale, Irondequoit and Merriton Limestones.
Cobleskill Limestone (Upper Silurian): Cobleskill Limestone - Bertie and Camillus Formations-dolostone, shale.
Cobleskill Limestone (Upper Silurian): Cobleskill Limestone; Bertie, Camillus, and Syracuse Formations - shale, dolostone; Brayman Shale.
Copake and Halcyon Lake Formations, Rochdale Limestone (Lower Ordovician): Copake and Halcyon Lake Formations, Rochdale Limestone - Columbia County: Copake Formation-limestone, dolostone; Halcyon Lake Formation-chert, calc-dolostone.
Copake and Rochdale Formations (Lower Ordovician): Copake and Rochdale Formations - Copake Formation-limestone, dolostone, siltstone; Rochdale Formation-limestone, dolostone; Halcyon Lake Dolostone-locally cherty.
Genesee Group (Upper Devonian): Genesee Group - West River Shale; Genundewa Limestone; Penn Yan and Geneseo Shales; all except Geneseo replaced eastwardly by Ithaca Formation-shale, siltstone and Sherburne Siltstone.
Genesee Group (Upper Devonian): Genesee Group - West River Shale; Genundewa Limestone; Penn Yan and Geneseo Shales; North Evans Limestone.
Germantown Formation (Cambrian): Germantown Formation - shale, limestone, conglomerate.
Germantown Formation (Cambrian): Germantown Formation - south of Troy; shale, conglomerate, limestone.
Glenerie Formation (Lower Devonian): Glenerie Formation - limestone, chert; Port Jervis Formation (near Port Jervis only)-shale, limestone, chert.
Glenerie Formation (Lower Devonian): Glenerie Formation - limestone, chert.
Helderberg Group (Lower Devonian): Helderberg Group - Coeymans and Manlius Limestones; Rondout Dolostone.
Helderberg Group (Lower Devonian): Helderberg Group - West of Albany: Alsen, Becraft, New Scotland, Kalkberg, Coeymans, and Manlius Limestones; Rondout Dolostone. South of Albany: Port Ewen, Alsen thru Manlius Limestones; Rondout Dolostone.
Helderberg Group (Lower Devonian): Helderberg Group - Alsen, Becraft, New Scotland, Kalkberg, Coeymans, and Manlius Limestones.
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.
Lockport Group (Upper Silurian): Lockport Group - Oak Orchard and Penfield Dolostones; both replaced eastwardly by Sconondoa Formation-limestone, dolostone.
Lockport Group (Upper Silurian): Lockport Group - consists of: Guelph, Oak Orchard, Eramosa, and Goat Island Dolostones; Gasport Limestone-local bioherms.
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.
Marcellus Formation (Middle Devonian): Marcellus Formation - In west: Oatka Creek Shale Member; In east: Cardiff and Chittenango Shale Members, Cherry Vale Limestone and Union Springs Shale Members.
Marcellus Formation (Middle Devonian): Marcellus Formation - Pecksport, Solsville, Otsego, and Chittenango shale and sandstone Members, Cherry Valley Limestone, and Union Springs Shale Members.
Moscow Formation (Middle Devonian): Moscow Formation - In west: Windom and Kashong Shales, Menteth Limestone Members; In east: Cooperstown Shale Member, Portland Point Limestone Member.
Moscow Formation (Middle Devonian): Moscow Formation - Windom and Kashong Shales, Menteth Limestone Members.
Onondaga Limestone (Middle Devonian): Onondaga Limestone - Seneca, Morehouse (cherty), and Nedrow Limestone Members, Edgecliff cherty Limestone Member, local bioherms.
Onondaga Limestone (Lower to Middle Devonian): Onondaga Limestone - Seneca, Morehouse (cherty), and Nedrow Limestone Members, Edgecliff cherty Limestone Member, local bioherms, Buttermilk Falls Limestone Member; Schoharie Formation-shale, limestone; Carlisle Center Siltstone; Esopus Shale.
Onondaga Limestone (Lower to Middle Devonian): Onondaga Limestone - Schoharie Formation-shale, limestone; Carlisle Center Siltstone; Esopus Shale.
Onondaga Limestone (Middle Devonian): Onondaga Limestone - Seneca, Morehouse (cherty), and Nedrow Limestone Members, Edgecliff cherty Limestone Member, local bioherms.
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.
Port Ewen thru Manlius Limestone, Rondout Dolostone, undifferentiated. (Upper Silurian - Lower Devonian): Port Ewen thru Manlius Limestone, Rondout Dolostone, undifferentiated.
Poultney Formation ("A" Member) (Cambrian): Poultney Formation ("A" Member) - north of Troy: shale, limestone; Hatch Hill Formation-shale, dolostone; West Castleton Formation-shale, limestone, conglomerate.
Poultney Formation ("A" Member) (Cambrian): Poultney Formation ("A" Member) - shale, limestone; Hatch Hill Formation-shale, dolostone; West Castleton Formation-shale, limestone, 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.
Skaneateles Formation (Middle Devonian): Skaneateles Formation - Levanna Shale, Stafford Limestone Members.
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.
Trenton Group (Middle Ordovician): Trenton Group - Denley, Sugar River, Kings Falls, and Rockland Limestones.
Trenton Group (Middle Ordovician): Trenton Group - In Black River Valley: Cobourg Formation-Hillier shale and limestone Member, Hallowell limestone Member; Denley, Sugar River, Kings Falls, and Rockland Limestones. In Champlain Valley: Glens Falls Formation-Montreal shale and limestone Member, Larrabee limestone Member.
Trenton and Black River Groups, undivided (Middle Ordovician): Trenton and Black River Groups, undivided - Mohawk Valley: Dolgeville, Denley, Sugar River, Kings Falls, Glens Falls, Rockland, Amsterdam, and Lowville Limestones. Washington County: Glens Falls and Orwell Limestones.
Trenton and Black River Groups, undivided (Middle Ordovician): Trenton and Black River Groups, undivided - Glens Falls and Orwell Limestones. In Canada: Lindsay, Verulam, Bodcaygeon, Gull River Limestones; Shadow Lake Dolostone.
Tully Limestone (Middle Devonian): Tully Limestone
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.
Valcour, Crown Point, and Day Point Limestones (Middle Ordovician): Valcour, Crown Point, and Day Point Limestones - locally reefy, Ste. Therese Siltstone at base; Middlebury Limestone in Vermont; St. Martin and Rockcliffe Limestones in St. Lawrence Valley. Includes some Otbr and Obk adjacent to Champlain Thrust in Vermont.
Wappinger Group (Cambrian - Lower Ordovician): Wappinger Group - (including Fishkill limestone and dolostone): Copake Formation ?-limestone, dolostone; Rochdale Formation-limestone, dolostone; Halcyon Lake Dolostone-locally cherty; Briarcliff Dolostone; Pine Plains Formation-dolostone, shale, oolite; Stissing Formation-dolostone, shale.
Winooski Dolostone, Monkton Quartzite, and Dunham (Rutland) Dolostone (Cambrian): Winooski Dolostone, Monkton Quartzite, and Dunham (Rutland) Dolostone

Ohio

Cedarville, Springfield, Euphemia, and Laurel Dolomites; Massie Shale, Undivided (Silurian): Cedarville, Springfield, Euphemia, and Laurel Dolomite; Massie Shale, Undivided - Cedarville Dolomite, white to gray to blue gray weathers gray; abundant intercrystalline, moldic, and vuggy porosity, massive bedded, 0 to 100 feet thick. Diagnostic features include porosity, cliff-forming nature of unit, and pentamerid brachiopod fossil zone near contact with Springfield Dolomite. Springfield Dolomite, gray to tan, mottled with brownish gray, massive bedded where unweathered and layered brick-like where weathered, 5 to 10 feet thick. Euphemia Dolomite, dolomite to dolomitic limestone, gray to bluish gray, massive bedded, 5 to 15 feet thick. Diagnostic features include large, blocky bedding where weathered and cliff forming nature. Massie Shale, gray to bluish gray, minor limestone and dolomite beds, calcareous, slakes easily, planar to irregular bedding, thin to thick bedded, 0 to 10 feet thick. Diagnostic feature includes calcareous shale with limestone and dolomite. Laurel Dolomite, gray to tan, weathers brown, argillaceous to nonargillaceous, wavy bedding, thin to medium bedded, 5 to 10 feet thick. Interval ranges from 115 to 140 feet thick. Euphemia Dolomite averages 1.6 to 2.6 m in thickness. Environment of deposition was normal marine offshore, free from clastic influence; similar to Cedarville Dolomite. Unconformably overlies Massie Shale. Correlates with Bisher Formation to the southeast. Age is Wenlockian (Ausich, 1987).
Cedarville, Springfield, and Euphemia Dolomites, Undivided (Silurian): Cedarville, Springfield, and Euphemia Dolomite, Undivided - Cedarville Dolomite, white to gray to blue gray, weathers gray, abundant intercrystalline, moldic, and vuggy porosity, massive bedded, 0 to 100 feet thick. Diagnostic features include porosity, cliff-forming nature of unit, and pentameriid brachiopod fossil zone near contact with Springfield Dolomite. Springfield Dolomite, gray to tan, mottled with brownish gray, massive bedded where unweathered and layered bricklike where weathered, 5 to 10 feet thick. Euphemia Dolomite, dolomite to dolomitic limestone, gray to bluish gray, massive bedded, 5 to 15 feet thick. Diagnostic features include large, blocky bedding where weathered and cliff forming nature. Interval ranges from 10 to 125 feet in thickness. Euphemia Dolomite averages 1.6 to 2.6 m in thickness. Environment of deposition was normal marine offshore, free from clastic influence; similar to Cedarville Dolomite. Unconformably overlies Massie Shale. Correlates with Bisher Formation to the southeast. Age is Wenlockian (Ausich, 1987).
Cincinnati Group as used by Wickstrom (1990) (Ordovician): Cincinnati Group as used by Wickstrom (1990) - Shale, dolomite and limestone, interbedded. Various shades of gray; thin to medium bedded; Data from core holes. Occurs beneath glacial drift.
Clinton and Cataract Groups, Undivided (Silurian): Clinton and Cataract Groups, Undivided - Dolomite, limestone and shale, interbedded. Various shades of gray, olive green, yellow and reddish-gray; laminated to thick bedded; argillaceous, glauconitic, pyritic, ferruginous and/or phosphatic; locally fossiliferous. Data from core holes. Occurs beneath glacial drift.
Columbus Limestone (Devonian): Columbus Limestone - Limestone and dolomite; gray to brown, weathers brown; massive bedding; upper 2/3 fossiliferous, gray limestone, lower 1/3 brown dolomite; 0 to 105 feet thick.
Dayton and Brassfield Limestones (Silurian): Dayton Limestone; gray to bluish-gray weathers grayish-white; medium to thick bedded; fine grained; dolomitic; 5 to 15 feet thick. Brassfield Limestone; white to pink, locally gray to reddish brown; irregular, thin to medium bedded; coarsely crystalline; abundant pelmatozoan fossils; grayish-green glauconitic partings; cliff forming; 20 to 50 feet thick. Interval ranges from 32 to 100 feet in thickness.
Delaware Limestone (Devonian): Delaware Limestone - Limestone; gray to brown; thin to massive bedded; argillaceous partings, nodules and layers, carbonaceous, petroliferous odor; as much as 45 feet thick.
Drakes, Whitewater and Liberty Formations, Undivided (Ordovician): Drakes, Whitewater and Liberty Formations, Undivided - Drakes Formation; shale(90%) and limestone/dolomite(10%), interbedded; gray and maroon,weathers yellowish gray; planar to irregular, thin to thick bedded; 20 to 30 feet thick. Whitewater Formation, limestone(60%) and shale(40%) interbedded; gray weathers yellowish gray; irregular to wavy, thin to medium bedded; 20 to 80 feet thick. Liberty Formation, limestone(50%) and shale(50%), interbedded; gray weathers yellowish gray; planar to irregular, thin to medium bedded; 20 to 40 feet thick. Interval ranges from 60 to 150 feet in thickness. The Geological Survey of Ohio recognizes the Cincinnati Group proposed by Meek and Worthen (1865), but at this time retains it as an informal term. The unit will be formally reinstated as a lithostratigraphic term after revision of its lower boundary and minor lithologic redescription of its units are completed. The ten formations included in the group are the (ascending) Clays Ferry Formation, the Kope Formation, the Fairview Formation, the Miamitown Shale, the Grant Lake Limestone, the Arnheim Formation, the Waynesville Formation, the Liberty Formation, the Whitewater Formation, and the Drakes Formation. Six members have been identified in the course of field mapping: the Point Pleasant Tongue of the Clays Ferry, the informal Bellevue, Corryville, Mount Auburn, and Straight Creek members of the Grant Lake Limestone, and the Preachersville Member of the Drakes Formation. The Backbone Creek and Elk Creek beds are recognized as excellent stratigraphic marker beds (Shrake and others, 1988).
Drowning Creek Formation (Silurian): Drowning Creek Formation - Limestone, and shale, interbedded; limestone, shades bluish, greenish, and yellowish gray to grayish-pink weathers light gray to shades of red; planar to irregular to nodular, thin to thick bedded; fine to very coarse grained; locally silty, dolomitic, cherty, glaconitic; moderate to abundant fossils. Shale, greenish-gray to bluish-gray weathers light gray, thin bedded; silty.
Dundee Limestone (Devonian): Dundee Limestone - Limestone; olive gray to brown; upper part thin bedded, lower part medium to thick bedded; fossiliferous in upper part becomes cherty dolomite in lower part; as much as 105 feet thick.
Grant Lake Limestone and Fairview Formation, Undivided (Ordovician): Grant Lake Limestone and Fairview Formation, Undivided - Limestone and shale, interbedded; gray to bluish-gray weathers light gray to yellowish-gray; planar to lenticular, thin to medium bedded in lower half; wavy to irregular to nodular, thin to thick bedded in upper half; fossiliferous.
Grant Lake and Fairview Formations, Miamitown Shale, Undivided (Ordovician): Grant Lake and Fairview Formations, Miamitown Shale, Undivided - Limestone (50%) and shale (50%), interbedded; gray to bluish-gray weathers light gray to yellowish-gray;, planar to lenticular, thin to medium bedded in lower half; wavy to irregular to nodular, thin to thick bedded in upper half; fossiliferous. Interval of shale (90%) with limestone (10%), as much as 35 feet thick, near middle of unit.
Grant Lake and Fairview Formations, Undivided (Ordovician): Grant Lake and Fairview Formations, Undivided - Limestone and shale, interbedded; gray to bluish-gray weathers light gray to yellowish-gray; planar to lenticular, thin to medium bedded in lower half; wavy to irregular to nodular, thin to thick bedded in upper half; fossiliferous. Percent limestone increases from about 50% of interval in lower half to as much as 80% in upper half of unit.
Kope Formation (Ordovician): Kope Formation - Shale(75%) and limestone(25%) interbedded; gray to bluish gray weathers light gray to yellowish gray; planar, thin to thick bedded; 200 to 260 feet thick.
Massie and Osgood Shales; Dayton and Brassfield Limestones; Laurel Dolomite; Undivided (Silurian): Massie and Osgood Shales; Dayton and Brassfield Limestones; Laurel Dolomite; Undivided - Massie Shale; gray to bluish gray; planar to irregular, thin to thick bedded; calcareous; slakes; minor limestone and dolomite beds; 0 to 10 feet thick. Laurel Dolomite; gray to tan, weathers brown; argillaceous to nonargillaceous; wavy, thin to medium bedded; 5 to 10 feet thick. Osgood Shale, blue gray to gray weathers brown; thin to massive bedded; calcareous with minor limestone and dolomite; slakes and slumps readily in outcrop; 3 to 25 feet thick. Dayton Limestone; gray to bluish-gray weathers grayish-white; medium to thick bedded; fine grained; dolomitic; 5 to 15 feet thick. Brassfield Limestone; white to pink, locally gray to reddish brown; irregular, thin to medium bedded; coarsely crystalline; abundant pelmatozoan fossils; grayish-green glauconitic partings; cliff forming; 20 to 50 feet thick. Interval ranges from 32 to 100 feet in thickness.
Olentangy Shale (Devonian): Olentangy Shale - Shale; greenish gray to medium gray; clayey; laminated to thin bedded; thin beds of brownish-gray shale in upper 2/3, limestone nodules in lower 1/3; 20 to 55 feet thick.
Ordovician Undifferentiated (Ordovician): Ordovician Undifferentiated - Shale, dolomite, and limestone, interbedded; various shades of gray; thin to medium bedding, structurally disturbed. Occurs only in Serpent Mound Impact Structure.
Plum Brook Shale (Devonian): Plum Brook Shale - Shale and argillaceous limestone; gray; thin bedded fossiliferous; 0 to 40 feet thick.
Point Pleasant Formation (Ordovician): Point Pleasant Formation - Limestone (60%) and shale (40%) interbedded; gray to bluish gray weathers light gray; planar to lenticular, thin to medium bedded; 0 to 80 feet thick.
Preacherville Member of the Drakes Formation, Waynesville and Arnheim Formation, Undivided (Ordovician): Preacherville Member of the Drakes Formation, Waynesville and Arnheim Formation, Undivided - Shale, limestone, and dolomite, interbedded; gray to maroon in upper part, weathers yellowish-gray to light-gray; planar to irregular to wavy to nodular, thin to thick bedded; shale increases upward.
Prout Limestone (Devonian): Limestone; olive gray; dolomitic in part; hard, siliceous; irregular bedding; pyrite, glauconite and phosphatic bone fragments at upper contact; 0 to 9 feet thick. Devonian (Givetian) Prout Limestone in OH contains corals superficially similar to those of lower part of Jaycox Shale Member of Ludlowville Formation in NY (Oliver, in press).
Waynesville and Arnheim Formations, Undivided (Ordovician): Waynesville and Arnheim Formations, Undivided - Waynesville Formation, shale(70%) and limestone(30%) interbedded; gray to bluish gray weathers light gray; planar to irregular, thin to thick bedded; 90 to 120 feet thick. Arnheim formation, shale(60%) and limestone(40%) interbedded; gray to bluish gray weathers light gray; planar, wavy, irregular, to nodular (in upper portion), thin to thick bedded; 50 to 100 feet thick. Contains multiple sedimentary cycles consisting of the alternation of shale and limestone displaying planar to irregular bedding with limestone and shale exhibiting wavy to nodular bedding. Ranges from 140 to 220 feet. The Geological Survey of Ohio recognizes the Cincinnati Group proposed by Meek and Worthen (1865), but at this time retains it as an informal term. The unit will be formally reinstated as a lithostratigraphic term after revision of its lower boundary and minor lithologic redescription of its units are completed. The ten formations included in the group are the (ascending) Clays Ferry Formation, the Kope Formation, the Fairview Formation, the Miamitown Shale, the Grant Lake Limestone, the Arnheim Formation, the Waynesville Formation, the Liberty Formation, the Whitewater Formation, and the Drakes Formation. Six members have been identified in the course of field mapping: the Point Pleasant Tongue of the Clays Ferry, the informal Bellevue, Corryville, Mount Auburn, and Straight Creek members of the Grant Lake Limestone, and the Preachersville Member of the Drakes Formation. The Backbone Creek and Elk Creek beds are recognized as excellent stratigraphic marker beds (Shrake and others, 1988).

Oklahoma

Arbuckle Group and Timbered Hills Group (Phanerozoic | Paleozoic | Cambrian-Furongian): CLINTON- Limestone and dolomite; one outlier at southern end of quadrangle, about 1,200 feet thick.
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.
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.
Belle City Formation or Limestone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle): OKLAHOMA CITY- "Belle City Limestone"-Consists of two fossiliferous limestone units with an intervening fossiliferous shale. Thickness ranges from 12 to 20 feet; present in southern part of area only, where it is below "Hilltop Formation". ARDMORE-SHERMAN- 'Belle City Formation"-Limestone, gray to buff, dense, in 2 beds each 2 to 3 feet thick, with interbedded dark-gray shale, 10 to 20 feet thick.
Bigfork Chert (Phanerozoic | Paleozoic | Ordovician-Middle): ARDMORE-SHERMAN- Limestone, gray, and dark-gray to black chert; thickness, 575 feet. Occurs in the OUACHITA MNTS. McALESTER TEXARKANA- Chert, dark-gray to black, with interbedded graptolitic black shales and fossiliferous gray to black cherty limestones; contains asphaltite seams; erodes into a mappable escarpment; thickness, 600 to 800 feet. (Same as Viola Limestone in Arbuckle Mountains.) 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.
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
Butterfly Dolomite + Signal Mountain Limestone + Royer Dolomite and Fort Sill Limestone (Phanerozoic | Paleozoic | Cambrian-Furongian): ARDMORE-SHERMAN- Limestone, gray, fine-grained, gradational eastward into tan to pink fine- to coarse-grained dolomites; thickness, 570 to 1,600 feet, decreasing eastward. (Arbuckle Group) Occurs in the ARBUCKLE MTNS
Caddo Formation (Phanerozoic | Mesozoic | Cretaceous-Early ): ARDMORE-SHERMAN-Limestones, marls, and shales; 150 feet thick. Subdivided into "Fort Worth Limestone" at top and "Duck Creek Limestone" below. McALESTER TEXARKANA- Limestones, white to cream, silty, alternating with gray shales, with "Texigryphaea washitaensis;" 7-foot bed at top (Fort Worth equivalent) and blue-gray silty shales and limestones below with "Texigryphaea navia" (Duck Creek equivalent); thickness, 150 feet. Ouachita Mountain uplift; S. OK folded belt province
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.
Collier Shale (Phanerozoic | Paleozoic | Cambrian-Furongian Ordovician-Early): McALESTER TEXARKANA- Shale and phyllite, dark-gray to black, with much limestone, some granitic and arkosic pebbles, many quartz and orthoclase pegmatities, and some galena and sphalerite; contains Lower Ordovician conodonts; base covered; exposed thickness, 200 feet. Viersen and Cochran's 25-1 Weyerhaeuser well (9-8-70), spudded in upper Collier to total depth of 10,019 feet in Southeast quarter of Northwest quarter of section 25, Township 5 South, Range 23 East, penetrated dark-gray to black phyllites, quartzites, and dolomitic marble without reaching basement (Goldstein, 1975). Occurs in POTATO HILLS, BROKEN BOW UPLIFT or ADJACENT SMALLER UPLIFTS IN SOUTHEASTERN PART OF OUACHITA MOUNTAINS
Colorado Group (Phanerozoic | Mesozoic | Cretaceous-Early ): CIMARRON- includes: Greenhorn Limestone: Gray fossiliferous limestone and calcareous shale. Graneros Shale: Dark-gray shale.
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
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).
DeQueen Limestone (Phanerozoic | Mesozoic | Cretaceous-Early ): 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.
Denton Clay (Phanerozoic | Mesozoic | Cretaceous-Early ): McALESTER TEXARKANA- Clay and shale, blue- to brownish-gray, and marly, fossiliferous limestone with "Texigryphaea washitaensis;" thickness, 45 to 65 feet.
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.
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
Eagle Ford Formation (Phanerozoic | Mesozoic | Cretaceous-Late ): ARDMORE-SHERMAN- Shale, dark-gray, plastic; thickness, about 50 feet; top eroded.
Fort Scott Limestone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle): TULSA- Limestone and shale. (Mapped with the Labette Formation south of Bird Creek inTulsa County)
Goodland Limestone and Walnut Clay (Phanerozoic | Mesozoic | Cretaceous-Early ): 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.
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.
Hogshooter Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle): TULSA- Limestone and some shale. (Mapped with the Nellie Bly Formation south of Bartlesville)
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)
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
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
Johns Valley Formation or Johns Valley Shale (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early): 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.
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.
Kiamichi Formation (Phanerozoic | Mesozoic | Cretaceous-Early ): 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
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
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.
Lenapah Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle): TULSA- Limestone and shale. (Map unit only in Nowata County)
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."
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.
Morrison Formation (Phanerozoic | Mesozoic | Jurassic-Late ): CIMARRON- Varicolored fine-grained sandstone, limestone, dolomite, shale, and conglomerate 0 to 470 +/- feet thick.
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.
Pine Top Chert (Phanerozoic | Paleozoic | Devonian-Early): McALESTER TEXARKANA- Limestone, chert, and cherty limestone, gray to light-gray to tan to white and pink; contains Haragan brachiopods; at top is an 8-foot chert conglomerate; base not exposed; thickness, 60 feet. Occurs in the OUACHITA MTNS NORTH OF TI VALLEY FAULT
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.
Pitkin + Fayetteville + Hindsville + Moorefield Formations (Phanerozoic | Paleozoic | Carboniferous Mississippian-Late): FORT SMITH- Mp "Pitkin Formation," limestone; "Fayetteville Formation," shale and limestone; "Hindsville Formation," limestone and shale; and "Moorefield Formation," limestone.
Sycamore and Welden Limestones (Phanerozoic | Paleozoic | Carboniferous Mississippian): ARDMORE-SHERMAN- Limestone, blue-gray to tan, silty, fine-grained; thickness, 2 to 370 feet, decreasing northeastward. Mapped separately in northeastern Arbuckle Mountains and Mannsville anticline; mapped elsewhere with underlying Woodford Shale. Occurs in the ARBUCKLE MTNS
Sylvan Shale + Fernvale Limestone and Viola Limestone (Phanerozoic | Paleozoic | Ordovician-Middle Ordovician-Late): ARDMORE-SHERMAN- "Sylvan," shale, dark-greenish-gray; thickness, 60 to 325 feet. "Fernvale" and "Viola," limestone, gray, fine- to coarse-grained; thickness, 350 to 900 feet. Occurs in the ARBUCKLE MTNS
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
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 (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
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
Upper part of Arbuckle Group (Phanerozoic | Paleozoic | Ordovician-Early): LAWTON- Predominantly limestone and dolomite, 4,000 feet (1,200 m) thick, faulted in isolated areas. "Upper part of Arbuckle Group undifferentiated," Oua, faulted in isolated areas north of Lawton.
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)
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 (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early): ARDMORE-SHERMAN- Limestone, gray to tan, fine-grained to oolitic. Mapped separately along Lawrence uplift as IPwal, 30 to 75 feet thick with gray shale, IPwas, below, about 160 feet thick. Occurs in the ARBUCKLE MTNS
Wapanucka Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early): ARDMORE-SHERMAN- Limestone, gray to tan, fine-grained to oolitic. Mapped separately along Lawrence uplift as IPwal, 30 to 75 feet thick with gray shale, IPwas, below, about 160 feet thick. Occurs in the ARBUCKLE MTNS
Wapanucka Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early): ARDMORE-SHERMAN- Limestone, gray to tan, fine-grained to oolitic. Mapped separately along Lawrence uplift as IPwal, 30 to 75 feet thick with gray shale, IPwas, below, about 160 feet thick. Occurs in the ARBUCKLE MTNS
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.
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
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

Oregon

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)

Pennsylvania

Allentown Formation (Cambrian): Allentown Formation - Medium- to medium-dark-gray, thick-bedded dolomite and impure limestone; dark-gray chert stringers and nodules; laminated; oolitic and stromatolitic; some orange-brown-weathering calcareous siltstone at base.
Annville Formation (Ordovician): Annville Formation - Light-gray, massive, high-calcium limestone; mottled at base.
Axemann Formation (Ordovician): Axemann Formation - Medium-gray fossiliferous limestone.
Beekmantown Group (Ordovician): Beekmantown Group - Includes, in descending order, the Pinesburg Station (Ops), Rockdale Run (Orr), and Stonehenge (Os) Formations.
Beekmantown Group (Ordovician): Beekmantown Group - Includes, in descending order, the Ontelaunee (Oo), Epler (Oe), Rickenbach (Ori), and Stonehenge (Os) Formations.
Bellefonte and Axemann Formations, undivided (Ordovician): Bellefonte and Axemann Formations, undivided - Includes, in descending order, the Bellefonte (Obf) and Axemann (Oa) Formations.
Benner Formation through Loysburg Formation, undivided (Ordovician): Benner Formation through Loysburg Formation, undivided - In descending order: Benner Formation--light- to dark-gray, thick-bedded limestone (calcilutite); includes chemically pure Valentine Member (Obv) at top, and, below, the less pure Valley View Member, which contains metabentonite beds--all laterally equivalent to impure limestones of Oak Hall Member; Stover Member at base is dark-gray limestone (calcilutite) having dolomite streaks; Benner is called "Linden Hall" by some workers. Snyder Formation--light- to medium-gray limestone, laminated to medium-bedded; has mud cracks, oolites, and dolomitic layers. Hatter Formation--medium-gray, fossiliferous, argillaceous limestone, laminated and dolomitic. Loysburg Formation--light- to medium-gray, medium-bedded limestone (Clover Member) overlying laminated, alternating limestone, dolomitic limestone, and dolomite (Milroy ["tiger-striped"] Member).
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.
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.
Chambersburg Formation (Ordovician): Chambersburg Formation - Dark-gray, cobbly, argillaceous limestone; abundant irregular shale partings; some metabentonite beds present.
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.
Coburn Formation through Loysburg Formation, undivided (Ordovician): Coburn Formation through Loysburg Formation, undivided - Includes, in descending order, the Coburn Formation through Nealmont Formation, undivided (Ocn) and Benner Formation through Loysburg Formation, undivided (Obl).
Coburn Formation through Nealmont Formation, undivided (Ordovician): Coburn Formation through Nealmont Formation, undivided - In descending order: Coburn Formation--medium-gray to very dark gray, very fossiliferous limestone and shaly limestone; Salona Formation--very dark gray to black, nonfossiliferous shaly limestone and calcareous shale containing metabentonite beds; Nealmont Formation--medium-gray fossiliferous limestone (calcarenite--Rodman Member) overlying thin-bedded shaly limestone (calcilutite--Center Hall Member).
Conestoga Formation (Ordovician and Cambrian): Conestoga Formation - Light-gray, thin-bedded, impure, contorted limestone having shale partings; conglomeratic at base; in Chester Valley, includes micaceous limestone in upper part, phyllite in middle, and alternating dolomite and limestone in lower part.
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.
Elbrook Formation (Cambrian): Elbrook Formation - Microcrystalline limestone and, in places, marble; includes subordinate dolomite containing abundant phyllitic layers; occurs in Chester and Montgomery Counties; relation to Elbrook of Cumberland Valley sequence is uncertain.
Elbrook Formation (Cambrian): Elbrook Formation - Light-colored calcareous shale and silty limestone at top; medium-gray limestone and dolomite in middle; pure, dark limestone at base.
Epler Formation (Ordovician): Epler Formation - Very finely crystalline, light-gray limestone interbedded with gray dolomite; coarsely crystalline limestone lenses present.
Epler Formation (Ordovician): Epler Formation - Thick-bedded, medium- to medium-dark-gray, finely crystalline limestone, weathering light gray; yellow dolomitic laminae; interbedded medium-dark-gray, finely crystalline dolomite, weathering yellowish gray; edgewise conglomerate; fossil-fragment and oolitic lenses.
Gatesburg Formation (Cambrian): Gatesburg Formation - Gray dolomite, limestone, and sandstone. Includes the Mines Member (CAgm) and four lower members (CAgl).
Hershey Formation through Annville Formation, undivided (Ordovician): Hershey Formation through Annville Formation, undivided - Includes, in descending order, the Hershey and Myerstown Formations, undivided (Ohm) and Annville Formation (Oan).
Hershey and Myerstown Formations, undivided (Ordovician): Hershey and Myerstown Formations, undivided - In descending order: Hershey--dark-gray to black, thin-bedded, argillaceous limestone; Myerstown--medium- to dark-gray, platy, medium-crystalline limestone; carbonaceous at base.
Jacksonburg Formation (Ordovician): Jacksonburg Formation - Dark-gray shaly limestone (cement rock) having slaty cleavage; basal medium- to thick-bedded limestone (cement limestone) increases in thickness eastward.
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.
Keyser and Tonoloway Formations, undivided (Devonian and Silurian): Keyser and Tonoloway Formations, undivided - In descending order: Keyser Formation--medium-gray, crystalline to nodular, fossiliferous limestone; upper part laminated and mud-cracked; not present east of Harrisburg; passes into lower Coeymans, Rondout, and Decker Formations in the east. Tonoloway Formation--medium-gray, laminated, mud-cracked limestone containing some medium-dark- or olive-gray shale interbeds; lower part passes into Wills Creek Formation east and south; passes into Bossardville and Poxono Island beds in the east.
Kinzers Formation (Cambrian): Kinzers Formation - Base--dark-brown shale; middle--gray and white spotted limestone and, locally, marble having irregular partings; top--sandy limestone which weathers to a fine-grained, friable, porous, sandy mass.
Limestone of Hamburg sequence (Ordovician): Limestone of Hamburg sequence - Conspicuous limestone.
Limestone of Martinsburg Formation (Ordovician): Limestone of Martinsburg Formation - Local limestone masses (wildflysch).
Limestone of Martinsburg Formation (Ordovician): Limestone of Martinsburg Formation - Dark-gray, thin-bedded, platy argillaceous limestone containing some beds of shale.
Lower (Middle?) Cambrian rocks, undivided (Cambrian): Lower (Middle?) Cambrian rocks, undivided - Lower Cambrian of Berks County includes tectonic slices of many of the following rock units: Zooks Corner (CAzc), Ledger (CAl), Kinzers (CAk), Vintage (CAv), Antietam (CAa, CAah), and Harpers (CAh, CAah) Formations.
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).
Marcellus Formation (Devonian): Marcellus Formation - Black shale; sparse marine fauna and siderite concretions. Contains local limestone ("Purcell") member. Tioga bentonite included at base in eastern Pennsylvania.
Millbach Formation (Cambrian): Millbach Formation - Pink to white and gray, finely laminated limestone and interbedded finely crystalline dolomite; numerous stromatolitic limestone beds.
Millbach and Schaefferstown Formations, undivided (Cambrian): Millbach and Schaefferstown Formations, undivided - Includes, in descending order, the Millbach Formation (CAm), and the Schaefferstown Formation--gray limestone containing siliceous and argillaceous laminae; thin bedded.
Monongahela Group (Pennsylvanian): Monongahela Group - Cyclic sequences of limestone, shale, sandstone, and coal; commercial coals present; base is at bottom of Pittsburgh coal.
Nittany and Stonehenge/Larke Formations, undivided (Ordovician): Nittany and Stonehenge/Larke Formations, undivided - Includes, in descending order, the Nittany (On) and Stonehenge/Larke (Osl) Formations.
Onondaga Formation (Devonian): Onondaga Formation - Medium-gray calcareous shale; marine fossils; medium-gray argillaceous limestone of Selinsgrove Member at top; called "Needmore Formation" west of 78° longitude; Tioga bentonite at top.
Ontelaunee Formation (Ordovician): Ontelaunee Formation - Light- to dark-gray, very finely to medium-crystalline dolomite containing interbeds of light-gray limestone; interbedded nodular, dark-gray chert at base.
Pinesburg Station Formation (Ordovician): Pinesburg Station Formation - Light-colored, thick-bedded, finely laminated dolomite; some limestone.
Pleasant Hill Formation (Cambrian): Pleasant Hill Formation - Gray, thin-bedded, argillaceous limestone interbedded with shale, siltstone, and sandstone.
Richland Formation (Cambrian): Richland Formation - Gray dolomite, in part oolitic, interbedded with medium-gray limestone and dark-gray oolitic chert.
Rockdale Run Formation (Ordovician): Rockdale Run Formation - Mostly limestone; some dolomite interbeds; some chert near middle and top; stromatolitic limestone in middle; pinkish marbleoid limestone and chert at base.
Shadygrove Formation (Cambrian): Shadygrove Formation - Pure, light-colored limestone, stromatolitic in part; abundant pinkish limestone and cream-colored chert.
Shriver, Mandata, Corriganville, and New Creek Members of Old Port Formation, undivided (Devonian): Shriver, Mandata, Corriganville, and New Creek Members of Old Port Formation, undivided - Limestone, chert, shale, and siliceous siltstone. In Fulton County, limestone and chert of the Licking Creek Member replaces the Shriver and Mandata.
Snitz Creek Formation (Cambrian): Snitz Creek Formation - Thick-bedded, medium- to coarsely crystalline dolomite, in part oolitic, containing laminated limestone and sandstone interbeds.
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.
St. Paul Group (Ordovician): St. Paul Group - Very finely crystalline, "birdseye" limestone at top and base, granular fossiliferous limestone, black chert, and dolomite in middle.
Stonehenge Formation (Ordovician): Stonehenge Formation - Gray, finely crystalline limestone containing dark-gray silty laminations; numerous edgewise conglomerate beds.
Stonehenge Formation (Ordovician): Stonehenge Formation - Stromatolitic, fine-grained limestone; includes coarser grained and conglomeratic, siliceous, laminated Stoufferstown Formation at base in most of Cumberland Valley.
Stonehenge Formation (Ordovician): Stonehenge Formation - Medium-light-gray to medium-gray, finely crystalline, thick-bedded limestone, containing dark siliceous laminae, edgewise conglomerate beds, and fossil-fragment lenses; dolomite beds increase in number eastward.
Stonehenge/Larke Formation (Ordovician): Stonehenge/Larke Formation - Medium-gray, medium-bedded to laminated, fossiliferous, oolitic limestone containing edgewise conglomerate; to the west, Stonehenge is laterally equivalent to medium- to dark-gray, coarsely crystalline dolomite (Larke).
Valentine Member of Benner Formation (Ordovician): Valentine Member of Benner Formation - Chemically pure limestone; occurs at top of Benner Formation.
Warrior Formation (Cambrian): Warrior Formation - Gray, thin- to medium-bedded, fossiliferous, cyclic limestone bearing stromatolites; interbedded with thick-bedded crystalline dolomite and some sandstone.
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

Hoppin Formation (Cambrian): Hoppin Formation - Quartz arenite, argillite, and minor limestone; contains fossils of Lower Cambrian age.

South Carolina

Bear Bluff Formation (Pliocene): Bear Bluff Formation: One of the older coastal terrace sequences in the Carolinas. Equivalent to Windsor Fm.
Peedee Formation (Cretaceous): Peedee Formation
Peedee Formation /Black Creek Group, undivided (Cretaceous): Peedee Formation /Black Creek Group, undivided
Waccamaw Formation (Pleistocene): Waccamaw Formation: Another Carolina costalized terrace of early-middle Pleistocene age. Deeply weathered.

South Dakota

Belle Fourche Shale (Phanerozoic | Mesozoic | Cretaceous-Late): Dark-gray to black bentonitic shale containing minor limestone lenses, bentonite layers, fossiliferous calcarenite, and large, ferruginous, carbonate concretions. Thickness 150-350 ft (46-107 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).
Greenhorn Formation (Phanerozoic | Mesozoic | Cretaceous-Late): Gray shale, mudstone, marl, calcarenite, and shaley limestone grading upward into light-gray to tan, alternating marl and thin-bedded, fossiliferous limestone. Thickness 225-315 ft (69-96 m).
Madison Group (Phanerozoic | Paleozoic | Devonian Carboniferous Mississippian): Includes: Pahasapa Limestone (Mississippian)-White, light-gray to tan, fine- to medium-crystalline limestone and dolomite containing brown to gray chert. Solution features including collapse breccia, sinkholes, and caves are prevalent. Thickness 300-630 ft (91-192 m). Englewood Formation (Mississippian to Dovonian)- Pink, lavender to light-gray, thin- to medium-bedded, finely crystalline, argillaceous, dolomitic limestone. Thickness 30-63 ft (9-19 m).
Niobrara Formation (Phanerozoic | Mesozoic | Cretaceous-Late): White to dark gray argillaceous chalk, marl, and shale. Weathers yellow to orange. Contains thin, laterally continuous bentonite beds, chalky carbonaceous shale, minor sand, and small concretions. Thickness 160-225 ft (49-69 m).
Pahasapa Limestone, Englewood Formation, Whitewood Limestone, Winnipeg Formation, and Deadwood Formation (Phanerozoic | Paleozoic | Cambrian Ordovician(?) Silurian(?) Devonian(?) Carboniferous Mississippian): Note: see individual descriptions

Tennessee

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.
Bigby-Cannon Limestone and Hermitage Formation (Ordovician): Bigby-Cannon Limestone - Dark- to light-gray, dense to medium-grained, medium- and even-bedded limestone. Thickness 80 to 150 feet; and Hermitage Formation - Gray, fine-grained, thin-bedded to laminated, sandy and argillaceous limestone; shale, weathers yellowish-brown; and nodular, shaly limestone. Thickness 50 to 100 feet.
Carters Limestone (Ordovician): Carters Limestone - Fine-grained, yellowish-brown limestone; thin-bedded in upper part; thicker bedded and very slightly cherty with scattered mottlings of magnesian limestone in lower part. Contains thin bentonite beds. Thickness 60 to 250 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.
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.
Chickamauga Group (Ordovician): Chickamauga Group - In the northwest predominantly a limestone sequence about 2,000 feet thick. Becomes progressively more clastic and thicker to the southeast.
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)
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.
Conococheague Limestone (Ordovician): 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.
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.
Fort Payne Formation and Chattanooga Shale (Mississippian): Fort Payne Formation - Calcareous and dolomitic silicastone; contains bedded chert, cherty limestone, and shale; scattered crinoidal limestone lenses. Thin green shale (Maury) at base. Thickness 100 to 275 feet.; and Chattanooga Shale - Black carbonaceous shale, fissile. Thickness 20 to 30 feet in most areas. (Mapped as MDc in Flynn Creek structure, where it is about 200 feet thick.) (Also mapped as MDc on the East Sheet)
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.
Holston Formation (Ordovician): 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.
Holston Formation (Ordovician): 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.
Honaker Dolomite (Cambrian): Honaker Dolomite - Dark-gray, medium-bedded dolomite with minor dark limestone beds; locally cherty; cryptozoans abundant in places. Thickness about 1,500 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.
Kingsport Formation (Ordovician): Kingsport Formation - Gray, fine-grained, sparingly cherty dolomite with basal dense, gray limestone sequence. Thickness about 250 feet.
Kingsport Formation (Ordovician): Kingsport Formation - Gray, fine-grained, sparingly cherty dolomite with basal dense, gray limestone sequence. Thickness about 250 feet.
Knox Group (Ordovician to Cambrian): Knox Group - Siliceous, well-bedded dolomite and magnesian limestone in the central and northwest belts of the Valley. To the southeast, much dark limestone is present and the rocks are only sparsely cherty. Thickness about 3,000 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.
Knox Group, including Newala Formation, Mascot Dolomite, Kingsport Formation, Longview Dolomite, Chepultepec Dolomite, and Copper Ridge Dolomite (Ordovician to Cambrian): Knox Group - Siliceous dolomite and magnesian limestone sequence. Thickness 2,500 to 3,000 feet.
Laurel Limestone, Osgood Formation, and Brassfield Formation (Silurian): Laurel Limestone - Dolomitic limestone, mottled yellowish-gray to yellowish-green, fine-grained. Thickness 0 to 10 feet. (Present only in Macon County); Osgood Formation - Grayish-green shale. Thickness 0 to 10 feet. (Present only in Macon County.); and Brassfield Formation - Olive-gray, fine-grained cherty limestone to the north, merging into olive-gray calcareous shale to the south. Thickness 60 to 130 feet. (Present only in Sequatchie Valley.)
Lebanon Limestone (Ordovician): Lebanon Limestone - Thin-bedded limestone, gray to yellowish-brown, slightly dolomitic, with thin calcareous shale partings. Thickness about 100 feet.
Lenoir Limestone (Ordovician): 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.
Lenoir Limestone (Ordovician): 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.
Longview Dolomite (Ordovician): Longview Dolomite - Siliceous, gray, fine-grained, medium-bedded dolomite; interbeds of gray limestone in upper part. Thickness about 300 feet.
Longview Dolomite (Ordovician): Longview Dolomite - Siliceous, gray, fine-grained, medium-bedded dolomite; interbeds of gray limestone in upper part. Thickness about 300 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.
Martinsburg Shale, including Reedsville Shale and Unnamed Limestone Unit (Ordovician): Martinsburg Shale - Bluish-gray, calcareous clay shale, weathers yellowish-brown; with thin beds of nodular gray, fossiliferous limestone; thin layers of metabentonite near base. Thickness about 1,000 feet. Incluldes Reedsville Shale - Greenish-gray calcareous shale. Thickness 200 to 400 feet. and Unnamed Limestone Unit - Medium-grained, fossiliferous, gray limestone, shaly in part. Thickness as much as 600 feet.
Maryville Limestone (Cambrian): Maryville Limestone - Gray, ribboned (silt and dolomite), fine-grained, evenly bedded limestone; intraformational conglomerate and oolitic layers common; clay shale and light-gray dolomite locally. Thickness 300 to 800 feet.
Maryville Limestone, Rogersville Shale, Rutledge Limestone (Cambrian): Maryville Limestone - Gray, ribboned (silt and dolomite), fine-grained, evenly bedded limestone; intraformational conglomerate and oolitic layers common; clay shale and light-gray dolomite locally. Thickness 300 to 800 feet; Rogersville Shale - Light-green, fissile clay shale; in places limestone (Craig Member) in upper part. Commonly 25 to 80 feet thick; maximum thickness 250 feet; Rutledge Limestone - Medium- to dark-gray, ribboned (silt and dolomite), medium-grained, well-bedded limestone; locally dark-gray, coarse-grained, medium-bedded dolomite in upper part. Thickness 100 to 500 feet.
Maryville, Rogersville, and Rutledge Formations (Cambrian): Maryville, Rogersville, and Rutledge Formations - Maryville and Rutledge are gray limestone, in part oolitic, with gray dolomite locally. Rogersville is green clay shale. Thickness 400 to 1,000 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.
Maynardville Limestone (Cambrian): Maynardville Limestone - Thick-bedded, bluish-gray, ribboned (silt and dolomite) nodular limestone; light-gray, fine-grained, laminated to thinly bedded, noncherty dolomite in upper part. Thickness 150 to 400 feet.
Maynardville Limestone (Cambrian): Maynardville Limestone - Thick-bedded, bluish-gray, ribboned (silt and dolomite), nodular limestone; light-gray, fine- grained, laminated to thin-bedded, noncherty dolomite in upper part. Thickness 150 to 400 feet.
Maynardville Limestone, Nolichucky Shale, Honaker Dolomite, Maryville Limestone, Rogersville Shale, Rutledge Limestone, Pumpkin Valley Shale (Cambrian): Maynardville Limestone - Thick-bedded, bluish-gray, ribboned (silt and dolomite) nodular limestone; light-gray, fine-grained, laminated to thinly bedded, noncherty dolomite in upper part. Thickness 150 to 400 feet; Nolichucky Shale - Pastel-colored (pink, greenish, olive), flaky clay shale; gray, commonly oolitic, shaly limestone lenses; locally stromatolitic limestone layers; thin, blocky siltstone near middle. Thickness 100 feet in the east to 900 feet in the west; Honaker Dolomite - Dark-gray, medium-bedded dolomite with minor dark limestone beds; locally cherty; cryptozoans abundant in places. Thickness about 1,500 feet; Maryville Limestone - Gray, ribboned (silt and dolomite), fine-grained, evenly bedded limestone; intraformational conglomerate and oolitic layers common; clay shale and light-gray dolomite locally. Thickness 300 to 800 feet; Rogersville Shale - Light-green, fissile clay shale; in places limestone (Craig Member) in upper part. Commonly 25 to 80 feet thick; maximum thickness 250 feet; Rutledge Limestone - Medium- to dark-gray, ribboned (silt and dolomite), medium-grained, well-bedded limestone; locally dark-gray, coarse-grained, medium-bedded dolomite in upper part. Thickness 100 to 500 feet; Pumpkin Valley Shale - Dull-brown to maroon shale with numerous interbeds of thin, blocky, and sandy siltstone. Thickness 100 to 600 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.
Midway Group including Porters Creek Clay and Clayton Formation (Tertiary): Midway Group - includes Porters Creek Clay - Pale-brown to brownish-gray, massive, blocky clay; locally contains glauconitic sand. Thickness 130 to 170 feet. Also includes Clayton Formation- Glauconitic sand, argillaceous and locally fossiliferous; at base in Hardeman County is an impure fossiliferous limestone. Thickness 30 to 70 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.
Monteagle Limestone (Mississippian): Monteagle Limestone - Mainly fragmental and oolitic, light-gray limestone; blocky bryozoan chert weathers from base. Thickness 180 to 300 feet.
Monteagle Limestone (Mississippian): Monteagle Limestone - Fragmental and oolitic limestone, light-gray; and fine-grained, brownish-gray limestone. Thickness 180 to 350 feet.
Nashville Group; Bigby-Cannon Limestone and Hermitage Formation (Ordovician): Nashville Group - Bigby-Cannon Limestone - Brownish-gray phosphatic calcarenite and light-gray to brownish-gray, cryptograined to medium- grained, even-bedded limestone. Thickness 50 to 125 feet; and Hermitage Formation - Thin-bedded to laminated, sandy and argillaceous limestone with shale; nodular shaly limestone; coquina; and phosphatic calcarenite. Thickness 50 to 100 feet.
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.
Nolichucky Shale (Cambrian): Nolichucky Shale - Pastel-colored (pink, greenish, olive), flaky clay shale; gray, commonly oolitic, shaly limestone lenses; locally stromatolitic limestone layers; thin, blocky siltstone near middle. Thickness 500 feet in the east to 900 feet in the west.
Nolichucky Shale (Cambrian): Nolichucky Shale - Pastel-colored (pink, greenish, olive), flaky clay shale; gray, commonly oolitic, shaly limestone lenses; locally stromatolitic limestone layers; thin, blocky siltstone near middle. Thickness 100 feet in the east to 900 feet in the west.
Nolichucky Shale, and Maryville, Rogersville, and Rutledge Formations, and Pumpkin Valley Shale (Cambrian): (Cn) Nolichucky Shale - Pastel-colored (pink, greenish, olive), flaky clay shale; gray, commonly oolitic, shaly limestone lenses; locally stromatolitic limestone layers; thin, blocky siltstone near middle. Thickness 500 feet in the east to 900 feet in the west.; (Cmr) Maryville, Rogersville, and Rutledge Formations - Maryvile and Rutledge are gray limestone, in part oolitic, with gray dolomite locally. Rogersville is green clay shale. Thickness 400 to 1,000 feet. Pumpkin Valley Shale - Dull-brown to maroon shale with numerous interbeds of thin, blocky, sandy siltstone. Thickness 100 to 600 feet.
Ordovician Breccia (Ordovician): Ordovician Breccia - Limestone and dolomite fragments ranging in size from a fraction of an inch to several feet.
Ordovician Breccia (Ordovician): Ordovician Breccia - Angular to subrounded fragments of limestone ranging in size from a fraction of an inch to several feet.
Ordovician Formations including Richmond Group (Mannie Shale, Fernvale Limestone), and Nashville Group (Hermitage Formation) (Ordovician): Ordovician Formations - Richmond Group (including Mannie Shale - Shale with thin beds of argillaceous limestone. Thickness 0 to 20 feet and Fernvale Limestone - Thick-bedded, coarse-grained limestone with vari-colored grains. Thickness 0 to 20 feet). and Nashville Group (including Hermitage Formation - Gray shale and thin-bedded to laminated, sandy and argillaceous limestone. Maximum exposed thickness 80 feet.)
Ordovician [units] including Richmond Group (which includes Mannie Shale, Fernvale Limestone, Sequatchie Formation, and Arnheim Formation), the Maysville Group (which includes Leipers Formation), the Eden Group (which includes Inman Formation), and the Nashville Group (which includes Catheys Formation) (Ordovician): Ordovician [units] including Richmond Group (which includes Mannie Shale - Olive-gray shale. Thickness 0 to 20 feet; Fernvale Limestone - Massive, coarsely crystalline, gray limestone with varicolored grains. Thickness 0 to 50 feet; Sequatchie Formation - Olive-gray and greenish-gray shale, mudstone, and argillaceous limestone; dolomitic, laminated, and sandy. Thickness 0 to 100 feet; and Arnheim Formation Nodular, shaly, gray limestone. Thickness 0 to 20 feet; the Maysville Group (which includes Leipers Formation - Nodular, shaly limestone; fine- to coarse-grained limestone; and phosphatic calcarenite locally. Thickness 0 to 150 feet); the Eden Group (which includes the Inman Formation - Thin-bedded to laminated, fine-grained, gray limestone with shale partings. Thickness 0 to 50 feet); and the Nashville Group (which includes Catheys Formation - Nodular, shaly limestone; fine- to coarse-grained limestone; phosphatic calcarenite; and light-gray cryptograined limestone. Thickness 50 to 175 feet.)
Ordovician formations, including Mannie Shale, Fernvale Limestone, Hermitage Formation, and Carters, Lebanon, Ridley, Pierce, and Murfreesboro Limestones (Ordovician): Ordovician formations - including Mannie Shale - Shale with thin beds of argillaceous limestone. Thickness 0 to 20 feet; Fernvale Limestone - Thick-bedded, coarse-grained, gray limestone with varicolored grains. Thickness 0 to 30 feet; Hermitage Formation - Gray shale and thin-bedded to laminated, sandy and argillaceous limestone. About 200 to 300 feet thick in Wells Creek Basin; only about 80 feet exposed in Western Valley; and the Carters, Lebanon, Ridley, Pierce, and Murfreesboro Limestones - Thin- to thick-bedded, cryptograined to coarse-grained, yellowish-brown to olive-gray limestones. Thickness about 1,000 feet. (Not exposed in Western Valley.)
Ottosee Shale (Ordovician): Ottosee Shale - Bluish-gray calcareous shale, weathers yellow; with reef lenses of coarsely crystalline reddish fossiliferous limestone ("marble"). Thickness about 1,000 feet.
Ottosee Shale (Ordovician): Ottosee Shale - Bluish-gray calcareous shale, weathers yellow; with reef lenses of coarsely crystalline reddish fossiliferous limestone ("marble"). Thickness about 1,000 feet.
Pierce and Murfreesboro Limestones (Ordovician): Pierce and Murfreesboro Limestones - Medium- to very thick-bedded, fine-grained, gray limestone; thin-bedded, nodular and shaly, greenish-gray limestone in places. Thickness 200 to 500 feet.
Ridley Limestone (Ordovician): Ridley Limestone - Medium- to very thick-bedded, fine- to medium-grained, gray dolomitic limestone, with prominent greenish-gray calcareous shale and shaly limestone unit in middle. Thickness 200 to 275 feet.
Rogersville Shale (Cambrian): Rogersville Shale - Light-green, fissile clay shale; in places limestone (Craig Member) in upper part. Commonly 25 to 80 feet thick; maximum thickness 250 feet.
Rutledge Limestone (Cambrian): Rutledge Limestone - Medium- to dark-gray, ribboned (silt and dolomite), medium-grained, well-bedded limestone; locally dark-gray, coarse-grained, medium-bedded dolomite in upper part. Thickness 100 to 500 feet.
Sequatchie Formation (Ordovician): Sequatchie Formation - Maroon and gray shaly limestone, mottled greenish; with interbeds of olive to maroon calcareous shale and siltstone. Thickness about 300 feet.
Sequatchie Formation (Ordovician): Sequatchie Formation - Maroon and gray shaly limestone, mottled greenish; with interbeds of calcareous, olive to maroon shale and siltstone. Average thickness about 200 feet.
Sequatchie Formation, Leipers Formation, Inman Formation and Catheys Formation (Ordovician): Sequatchie Formation - Greenish-gray calcareous shale, mudstone, and argillaceous limestone; dolomitic, laminated, and sandy. Thickness 0 to 165 feet; Leipers Formation - Nodular, shaly limestone and fine- to coarse-grained limestone. Thickness 0 to 150 feet; Inman Formation - Thin-bedded to laminated, fine-grained, greenish-gray limestone interbedded with red and green calcareous shale beds. Thickness 0 to 50 feet. (Present only in Sequatchie Valley.); and Catheys Formation - Nodular, shaly, thin- to medium-bedded limestone and fine- to coarse-grained limestone. Thickness 125 to 400 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.
Shady Dolomite (Cambrian): Shady Dolomite - Light-gray dolomite and thinly bedded limestone with much shaly gray limestone and calcareous gray shale. Thickness about 1,000 feet.
Shady Dolomite (Cambrian): Shady Dolomite - Light-gray, well-bedded dolomite with thin- to medium-bedded gray limestone; yellowish-brown residual clays with "jasperoid" diagnostic. Thickness about 1,000 feet.
Silurian Formations, including Decatur Limestone, Brownsport Group (Lobelville Formation, Bob Limestone, Beech River Formation), Wayne Group (Dixon Formation, Lego Formation, Waldron Shale, Laurel Limestone, Osgood Formation) and Brassfield Limestone (Silurian): Silurian Formations - Characteristically light olive-gray to greenish-gray, with variable reddish-brown color in some areas. Individual formations are generally uniform in thickness, except where truncated by pre- Chattanooga erosion. Most formations are slightly thicker (than indicated) in Wells Creek Basin. Includes Decatur Limestone- Thick-bedded, medium- to coarse-grained limestone, gray with reddish-brown grains. Thickness 0 to 70 feet; Brownsport Group ( which includes Lobelville Formation - Shale with thin beds of limestone. Thickness 0 to 30 feet; Bob Limestone - Thick-bedded, medium-grained limestone, locally oolitic. Thickness 0 to 25 feet; and Beech River Formation - Shale with thin beds of limestone. Thickness 0 to 60 feet); Wayne Group (which includes Dixon Formation - Green and reddish-brown argillaceous limestone, shale, and mudstone. Thickness 0 to 40 feet; Lego Limestone - Even-bedded, olive-gray limestone with scattered reddish-brown grains. Thickness 0 to 30 feet; Waldron Shale - Greenish-gray fossiliferous shale. Thickness 0 to 5 feet; Laurel Limestone - Even-bedded, olive-gray limestone with scattered reddish-brown grains. Thickness 0 to 30 feet; Osgood Formation - Greenish- and reddish-gray shale and argillaceous limestone. Thickness 0 to 15 feet); and Brassfield Limestone - Thin-bedded cherty limestone, locally glauconitic. Thickness 0 to 50 feet; generally about 20 feet.
Silurian Formations, including Decatur Limestone, Brownsport Group (Lobelville Formation, Bob Limestone, Beech River Formation), Wayne Group (Dixon Formation, Lego Formation, Waldron Shale, Laurel Limestone, Osgood Formation) and Brassfield Limestone (Silurian): Silurian Formations - A complete section of Silurian formations is not common because of pre-Chattanooga and/or pre- Cretaceous erosion. Where preserved, Silurian formations are remarkably uniform in thickness and are characteristically light olive-gray to greenish-gray with variable reddish-brown color in some area;. Decatur Limestone - Thick-bedded, medium- to coarse-grained limestone, gray with reddish-brown grains. Thickness 0 to 70 feet; Brownsport Group which includes 1) Lobelville Formation - Shale with thin beds of limestone. Thickness 0 to 40 feet; 2) Bob Limestone - Thick-bedded, medium-grained limestone, locally oolitic. Thickness 0 to 25 feet; and 3) Beech River Formation - Shale with thin beds of limestone. Thickness 0 to 60 feet; Wayne Group which includes: 1) Dixon Formation - Green and reddish-brown argillaceous limestone, shale, and mudstone. Thickness 0 to 40 feet; 2) Lego Limestone - Even-bedded, olive-gray limestone with scattered reddish-brown grains. Thickness 0 to 30 feet; 3) Waldron Shale - Greenish-gray fossiliferous shale. Thickness 0 to 5 feet; 4) Laurel Limestone - Even-bedded, gray limestone with scattered reddish-brown grains. Thickness 0 to 30 feet; 5) Osgood Formation - Greenish- and reddish-gray shale and argillaceous limestone. Thickness 0 to 15 feet.; and Brassfield Limestone - Thin-bedded cherty limestone, locally glauconitic. Thickness 0 to 20 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.
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 100 to 280 feet; and Warsaw Limestone - Coarse-grained, gray, crossbedded limestone; somewhat shaly in the northeast. Thickness 40 to 150 feet.
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.
Stones River Group; Carters Limestone (Ordovician): Stones River Group; Carters Limestone - Fine-grained, yellowish-brown limestone; thin-bedded in upper part; thicker bedded and very slightly cherty with scattered mottlings of magnesian limestone in lower part. Contains thin bentonite beds. Thickness 50 to 100 feet.
Stones River Group; Lebanon Limestone (Ordovician): Stones River Group; Lebanon Limestone - Thin-bedded, gray limestone with calcareous shale partings. Thickness 80 to 100 feet.
Stones River Group; Pierce Limestone and Murfreesboro Limestone (Ordovician): Stones River Group; Pierce Limestone - Gray, thin-bedded limestone with shale partings. Thickness 25 feet; and Murfreesboro Limestone - Thick-bedded, dark-gray, fine-grained limestone, with mottlings of magnesian limestone; somewhat cherty in upper part. Maximum exposed thickness 70 feet.
Stones River Group; Ridley Limestone (Ordovician): Stones River Group; Ridley Limestone - Thick-bedded, brownish-gray limestone, fine-grained, with minor mottlings of magnesian limestone; slightly cherty. Thickness 90 to 150 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.
Wells Creek Dolomite and Knox Group (Ordovician): Wells Creek Dolomite and Knox Group - Yellowish-gray and light olive-gray dolomite, within partings of grayish-green shale, and pale- orange to yellowish-gray limestone; thin- to thick-bedded, micrograined to coarse-grained. Present only in Wells Creek Basin. Exposed thickness at least 600 feet. (Also mapped with Onc on East-Central Sheet)
Wells Creek Formation and Knox Group (above Copper Ridge Dolomite) (Ordovician): Wells Creek Formation - Gray limestone and dolomite, with angular chert blocks and fragments; and minor shale, mottled red and green, calcareous. Thickness 0 to 50 feet. (Present only in Sequatchie Valley.); and Knox Group (above Copper Ridge Dolomite) - Gray, cherty dolomite and limestone, fine- to medium-grained. Maximum exposed thickness in Sequatchie Valley 600 feet. (Units in Onc are also mapped as OCk on the West-Central Sheet)

Texas

Admiral Formation (Phanerozoic | Paleozoic | Permian [Wolfcamp]): Admiral Formation
Allamore Formation (preCambrian-Proterozoic [Grenville]): Allamore Formation
Anacacho Limestone (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian]): Anacacho Limestone
Annona Chalk (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian]): Annona Chalk
Austin Chalk (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian]): Austin Chalk
Barnett Formation, Chappel Limestone, Houy, Zesch, Bear Spring, and Stribling Formations, and Pillar Bluff Limestone, undivided (Phanerozoic | Paleozoic | Devonian Carboniferous Mississippian-Early Mississippian-Middle Mississippian-Late): Barnett Formation, Chappel Limestone, Houy, Zesch, Bear Spring, and Stribling Formations, and Pillar Bluff Limestone, undivided
Bead Mountain Formation (Phanerozoic | Paleozoic | Permian [Leonard]): Bead Mountain Formation
Bell Canyon Formation (Phanerozoic | Paleozoic | Permian [Guadalupe]): Bell Canyon Formation
Bell Canyon, Cherry Canyon, and Brushy Canyon Formations undivided (Phanerozoic | Paleozoic | Permian [Guadalupe]): Bell Canyon, Cherry Canyon, and Brushy Canyon Formations undivided
Benevides Formation and Finlay Limestone, undivided (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean]): Benevides Formation and Finlay Limestone, undivided
Bissett Conglomerate (Phanerozoic | Mesozoic | Cretaceous-Early): Bissett Conglomerate
Bluff Mesa Formation (Phanerozoic | Mesozoic | Cretaceous-Early): Bluff Mesa Formation
Bone Spring Formation (Phanerozoic | Paleozoic | Permian [Leonard]): Bone Spring Formation
Boracho Limestone (Phanerozoic | Mesozoic | Cretaceous-Early): Boracho Limestone
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.
Bouquillas Formation (Phanerozoic | Mesozoic | Cretaceous-Late): Bouquillas Formation
Brushy Canyon Formation (Phanerozoic | Paleozoic | Permian [Guadalupe]): Brushy Canyon Formation
Buda Limestone (Phanerozoic | Mesozoic | Cretaceous-Early): Buda Limestone
Buda Limestone and Del Rio Clay, undivided (Phanerozoic | Mesozoic | Cretaceous-Late): Buda Limestone and Del Rio Clay, undivided
Buda Limestone and Eagle Mountain Sandstone, undivided (Phanerozoic | Mesozoic | Cretaceous-Late): Buda Limestone and Eagle Mountain Sandstone, undivided
Buda Limestone and San Martine Member of Borache Limestone, undivided (Phanerozoic | Mesozoic | Cretaceous-Late): Buda Limestone and San Martine Member of Borache Limestone, undivided
Burnam Limestone (Phanerozoic | Paleozoic| Ordovician-Late): Burnam Limestone 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.
Campagrande Formation (Phanerozoic | Mesozoic | Cretaceous-Early): Campagrande Formation
Canyon Group, undivided (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Missouri]): Canyon Group, undivided
Capitan Formation (Phanerozoic | Paleozoic | Permian [Guadalupe]): Capitan Formation
Carlsbad Group (Phanerozoic | Paleozoic | Permian [Guadalupe]): Carlsbad Group
Cedarton Shale and Adams Branch Limestone, undivided (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Missouri]): Cedarton Shale and Adams Branch Limestone, undivided
Chico Ridge Limestone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Missouri]): Chico Ridge Limestone
Cibolo Formation (Phanerozoic | Paleozoic | Permian [Leonard]): Cibolo Formation
Coleman Junction Formation (Phanerozoic | Paleozoic | Permian [Wolfcamp]): Coleman Junction Formation
Comanche Peak Limestone (Phanerozoic | Mesozoic | Cretaceous-Early [Albian]): Comanche Peak Limestone 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.
Comanche Peak Limestone and Walnut Clay, undivided (Phanerozoic | Mesozoic | Cretaceous-Early): Comanche Peak Limestone and Walnut Clay, undivided
Comanche Peak Limestone, Walnut Clay, and Antlers Sand, undivided (Phanerozoic | Mesozoic | Cretaceous-Early): Comanche Peak Limestone, Walnut Clay, and Antlers Sand, undivided
Comanchean rocks, undivided (Phanerozoic | Mesozoic | Cretaceous-Early [Washita]): Comanchean rocks, undivided
Cow Creek Limestone, Hammett Shale, and Sycamore Sand, undivided (Phanerozoic | Mesozoic | Cretaceous-Early): Cow Creek Limestone, Hammett Shale, and Sycamore Sand, undivided
Cox Sandstone (Phanerozoic | Mesozoic | Cretaceous-Early): Cox Sandstone
Cretaceous rocks, undivided (Phanerozoic | Mesozoic | Cretaceous-Late): Cretaceous rocks, undivided
Del Carmen Limestone (Phanerozoic | Mesozoic | Cretaceous-Early ): Del Carmen Limestone
Del Rio Clay (Phanerozoic | Mesozoic | Cretaceous-Late): Del Rio Clay
Del Rio Clay and Georgetown Limestone, undivided (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian] ): Del Rio Clay and Georgetown Limestone, undivided
Devils River Limestone (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean]): Devils River Limestone
Dimple Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early): Dimple Formation
Dockum Group, undivided (Phanerozoic | Mesozoic | Triassic-Late): Dockum Group
Duck Creek Limestone (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean]): Duck Creek Limestone
Duck Creek Limestone and Kiamichi Formation, undivided (Phanerozoic | Mesozoic | Cretaceous-Early): Duck Creek Limestone and Kiamichi Formation, undivided
Eagle Ford Formation (Phanerozoic | Mesozoic | Cretaceous-Late): Eagle Ford Formation
Eagle Ford Formation and Buda Limestone, undivided (Phanerozoic | Mesozoic | Cretaceous-Late): Eagle Ford Formation and Buda Limestone, undivided
Ector Chalk (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian]): Ector Chalk
Edwards Limestone (Phanerozoic | Mesozoic | Cretaceous-Early): Edwards Limestone
Edwards Limestone and Antlers Sand, undivided (Phanerozoic | Mesozoic | Cretaceous-Early): Edwards Limestone and Antlers Sand, undivided
Edwards and Comanche Peak Limestones, undivided (Phanerozoic | Mesozoic | Cretaceous-Early): Edwards and Comanche Peak Limestones, undivided
El Paso Formation and Bliss Sandstone, undivided (Phanerozoic | Paleozoic| Cambrian-Furongian(?) Ordovician-Early): El Paso Formation and Bliss Sandstone, undivided
Elm Creek Formation (Phanerozoic | Paleozoic | Permian [Leonard]): Elm Creek Formation
Espy Formation (Phanerozoic | Mesozoic | Cretaceous-Early): Espy Formation
Etholen Conglomerate (Phanerozoic | Mesozoic | Cretaceous-Early): Etholen Conglomerate
Finlay Limestone (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean Albian]): Finlay Limestone
Fort Worth Limestone and Duck Creek Formation, undivided (Phanerozoic | Mesozoic | Cretaceous-Early): Fort Worth Limestone and Duck Creek Formation, undivided
Fredericksberg Group and Maxon Sandstone, undivided (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean]): Fredericksberg Group and Maxon Sandstone, undivided
Fredericksburg Group (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean]): Fredericksburg Group
Fusselman Dolomite (Phanerozoic | Paleozoic | Silurian): Fusselman Dolomite
Gaptank Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early Pennsylvanian-Middle Pennsylvanian-Late): Gaptank Formation
Georgetown Limestone (Phanerozoic | Mesozoic | Cretaceous-Early): Georgetown Limestone
Glen Rose Limestone (Phanerozoic | Mesozoic | Cretaceous-Early): Glen Rose Limestone
Gober Chalk and Roxton Limestone (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian]): Gober Chalk and Roxton Limestone
Goodland Limestone and Walnut Clay, undivided (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean]): Goodland Limestone and Walnut Clay, undivided
Gorman Formation (Phanerozoic | Paleozoic| Ordovician-Early): Gorman Formation
Grape Creek Formation (Phanerozoic | Paleozoic | Permian [Leonard]): Grape Creek Formation
Grayson Marl and Main Street Limestone, undivided (Phanerozoic | Mesozoic | Cretaceous-Early Cretaceous-Late): Grayson Marl and Main Street Limestone, undivided
Grindstone Creek Formation, expanded (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Des Moines]): Grindstone Creek Formation, expanded
Gulfian rocks, undivided (Phanerozoic | Mesozoic | Cretaceous-Late): Gulfian rocks, undivided
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
Hensell Sand (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean): Hensell Sand
Home Creek Limestone and Colony Creek Shale, undivided (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Missouri]): Home Creek Limestone and Colony Creek Shale, undivided
Honeycut Formation (Phanerozoic | Paleozoic | Ordovician-Early): Honeycut Formation
Hueco Limestone (Phanerozoic | Paleozoic | Permian [Wolfcamp]): Hueco Limestone
Jagger Bend and Valera Formations, undivided (Phanerozoic | Paleozoic | Permian [Leonard]): Jagger Bend and Valera Formations, undivided
Kiamichi Formation (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean]): Kiamichi Formation
Kincaid Formation (Phanerozoic | Cenozoic | Tertiary | Paleocene): Kincaid Formation
Lazy Bend Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Des Moines]): Lazy Bend Formation
Lenox Hills and Neal Ranch Formations, undivided (Phanerozoic | Paleozoic | Permian [Wolfcamp]): Lenox Hills and Neal Ranch Formations, undivided
Loma Plata Formation (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean]): Loma Plata Formation
Lueders Formation (Phanerozoic | Paleozoic | Permian [Leonard]): Lueders Formation
Magdalena Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian Permian (?)): Magdalena Formation
Malone Formation (Phanerozoic | Mesozoic | Jurassic-Late): Malone Formation
Marble Falls Limestone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Morrow]): Marble Falls Limestone
Marlbrook Marl (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian]): Marlbrook Marl
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
McKnight Formation (Phanerozoic | Mesozoic | Cretaceous-Early ): McKnight Formation
Midway Group, undivided (Phanerozoic | Cenozoic | Tertiary | Paleocene): Midway Group, undivided
Mina Grande Formation (Phanerozoic | Paleozoic | Permian [Guadalupe]): Mina Grande Formation
Mineral Wells Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Missouri]): Mineral Wells Formation
Mississippi, Devonian, and Ordovician rocks, undivided (Phanerozoic | Paleozoic | Ordovician Devonian Carboniferous Mississippian): Mississippi, Devonian, and Ordovician rocks, undivided
Montoya Dolomite (Phanerozoic | Paleozoic | Ordovician-Middle Ordovician-Late): Montoya Dolomite
Moran Formation (Phanerozoic | Paleozoic | Permian [Wolfcamp]): Moran Formation
Mundy Breccia and Castner Limestone, undivided (preCambrian-Proterozoic): Mundy Breccia and Castner Limestone, undivided
Munn Formation (Phanerozoic | Paleozoic | Permian [Guadalupe]): Munn Formation
Ojinaga Formation (Phanerozoic | Mesozoic | Cretaceous-Late): Ojinaga Formation
Ordovician rocks, undivided (Phanerozoic | Paleozoic| Ordovician): Ordovician rocks, undivided
Paleozoic rocks, undivided (Phanerozoic | Paleozoic): Paleozoic rocks, undivided
Palo Pinto Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Missouri]): Palo Pinto Formation
Palo Pinto and Mineral Wells Formations, undivided (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Missouri]): Palo Pinto and Mineral Wells 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.
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
Pawpaw Formation and upper limestone unit of Weno Formation, undivided (Phanerozoic | Mesozoic | Cretaceous-Early): Pawpaw Formation and upper limestone unit of Weno Formation, undivided
Pawpaw Formation, Weno Limestone, and Denton Clay, undivided (Phanerozoic | Mesozoic | Cretaceous-Early): Pawpaw Formation, Weno Limestone, and Denton Clay, undivided
Pecan Gap Chalk (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian]): Pecan Gap Chalk
Petrolia Formation (Phanerozoic | Paleozoic | Permian [Wolfcamp Leonard]): Petrolia Formation
Pinto Canyon Formation (Phanerozoic | Paleozoic | Permian [Leonard Guadalupe]): Pinto Canyon Formation
Ranger Limestone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Missouri]): Ranger Limestone
Ranger Limestone and Placid Creek Shale, undivided (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Missouri]): Ranger Limestone and Placid Creek Shale, undivided
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
Rustler Formation (Phanerozoic | Paleozoic | Permian [Ochoa]): Rustler Formation
Salado and Castile Formations, undivided (Phanerozoic | Paleozoic | Permian [Ochoa]): Salado and Castile Formations, undivided
Salmon Peak Limestone (Phanerozoic | Mesozoic | Cretaceous-Early): Salmon Peak Limestone
San Miguel Formation (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian]): San Miguel Formation
Santa Elena Limestone (Phanerozoic | Mesozoic | Cretaceous-Early): Santa Elena Limestone
Santa Elena Limestone, Sue Peaks Formation, Del Carmen Limestone, and Telephone Canyon Formation, undivided (Phanerozoic | Mesozoic | Cretaceous-Early): Santa Elena Limestone, Sue Peaks Formation, Del Carmen Limestone, and Telephone Canyon Formation, undivided
Sedwick Formation (Phanerozoic | Paleozoic | Permian [Wolfcamp]): Sedwick Formation
Sedwick and Moran Formations, undivided (Phanerozoic | Paleozoic | Permian [Wolfcamp]): Sedwick and Moran Formations, undivided
Seven Rivers Formation (Phanerozoic | Paleozoic | Permian [Guadalupe]): Seven Rivers Formation
Skinner Ranch and Hess Formations, undivided (Phanerozoic | Paleozoic | Permian [Wolfcamp]): Skinner Ranch and Hess Formations, undivided
Smithwick Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Atoka]): Smithwick Formation
Starke Limestone (Phanerozoic | Paleozoic | Silurian): Starke Limestone 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.
Sue Peaks Formation (Phanerozoic | Mesozoic | Cretaceous-Early): Sue Peaks Formation
Sue Peaks Formation, Del Carmen Limestone, and Telephone Canyon Formation, undivided (Phanerozoic | Mesozoic | Cretaceous-Early): Sue Peaks Formation, Del Carmen Limestone, and Telephone Canyon Formation, undivided
Talpa Formation (Phanerozoic | Paleozoic | Permian [Leonard]): Talpa Formation
Tansill Formation (Phanerozoic | Paleozoic | Permian [Guadalupe]): Tansill Formation
Tanyard Formation (Phanerozoic | Paleozoic | Ordovician-Early): Tanyard Formation
Tessey Limestone (Phanerozoic | Paleozoic | Permian [Ochoa]): Tessey Limestone
Torcer Formation (Phanerozoic | Mesozoic | Cretaceous-Early): Torcer Formation
Toy Limestone (Phanerozoic | Cenozoic | Quaternary | Pleistocene-Early(?)): Toy Limestone
Travis Peak Formation (Phanerozoic | Mesozoic | Cretaceous-Early): Travis Peak Formation
Ventioner Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Missouri]): Ventioner Formation
Victorio Peak Formation (Phanerozoic | Paleozoic | Permian [Leonard]): Victorio Peak Formation
Walnut Clay (Phanerozoic | Mesozoic | Cretaceous-Early): Walnut Clay
Washita Group (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean] Cretaceous-Late ): Washita Group
Washita and Fredericksburg Groups, undivided (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean]): Washita and Fredericksburg Groups, undivided
West Nueces Formation (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean]): West Nueces Formation
Wilberns Formation showing Point Peak, Morgan Creek Limestone, and Welge Sandstone Members, undivided (Phanerozoic | Paleozoic | Cambrian-Furongian): Wilberns Formation showing Point Peak, Morgan Creek Limestone, and Welge Sandstone Members, undivided
Wilberns Formation showing San Saba Member (Phanerozoic | Paleozoic | Cambrian-Furongian): Wilberns Formation showing San Saba Member
Wilke Ranch Formation (Phanerozoic | Paleozoic | Permian [Leonard]): Wilke Ranch Formation
Willow Point Formation (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Missouri]): Willow Point Formation
Wills Point Formation (Phanerozoic | Cenozoic | Tertiary | Paleocene): Wills Point Formation
Winchell Limestone (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Missouri]): Winchell Limestone
Wolf Mountain Shale (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Missouri]): Wolf Mountain Shale
Word Formation (Phanerozoic | Paleozoic | Permian [Guadalupe]): Word Formation
Yearwood Formation (Phanerozoic | Mesozoic | Cretaceous-Early): Yearwood Formation
lower part of Washita Group (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean]): lower part of Washita Group
pre-Brazos River rocks, undivided (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian [Des Moines]): pre-Brazos River rocks, undivided
undivided part Fredericksberg Group (Phanerozoic | Mesozoic | Cretaceous-Early): undivided part Fredericksberg Group
undivided part of Washita Group (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean]): undivided part of Washita Group
undivided parts of Washita and Fredericksberg Groups (Phanerozoic | Mesozoic | Cretaceous-Early): undivided parts of Washita and Fredericksberg Groups
unnamed Pennsylvanian rocks (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian): unnamed Pennsylvanian rocks
upper Cretaceous rocks, undivided (Phanerozoic | Mesozoic | Cretaceous-Late): upper Cretaceous rocks, undivided

Utah

Cretaceous (2) sedimentary rocks in southeastern Utah (Late Cretaceous)
Devonian sedimentary rocks in central Utah (Devonian)
Devonian sedimentary rocks in southewestern Utah (Devonian)
Devonian sedimentary rocks in western Utah (Devonian to Mississippian)
Jurassic (1) sedimentary rocks in Salt Lake City-Coalville-Randolph region (Middle to Late Jurassic)
Jurassic (1) sedimentary rocks in southeastern Utah (Middle Jurassic)
Middle Cambrian shale and carbonate rocks in Logan-Huntsville Allochthon (Middle Cambrian)
Middle Cambrian shale and carbonate rocks in Uinta Mountains-Uinta Basin area (Middle Cambrian)
Middle Cambrian shale and carbonate rocks in central Utah (Middle Cambrian)
Middle Cambrian shale and carbonate rocks in southwestern Utah (Middle Cambrian)
Middle Cambrian shale and carbonate rocks in western Utah (Middle Cambrian)
Mississippian (1) carbonate rocks in Logan-Huntsville Allochthon (Mississippian)
Mississippian (1) carbonate rocks in Salt Lake City-Coalville-Randolph region (Mississippian)
Mississippian (1) carbonate rocks in Uinta Mountains-Uinta Basin region (Mississippian)
Mississippian (1) carbonate rocks in central Utah (Late Devonian to Mississippian)
Mississippian (1) carbonate rocks in southwestern Utah (Mississippian)
Mississippian (1) carbonate rocks in western Utah (Mississippian)
Mississippian (2) sedimentary rocks in Uinta Mountains-Uinta Basin region (Mississippian)
Mississippian (2) sedimentary rocks in central Utah (Mississippian)
Mississippian (2) sedimentary rocks in western Utah (Mississippian)
Mississippian (3) sedimentary rocks in Logan-Huntsville Allochthon (Mississippian)
Mississippian (3) sedimentary rocks in Uinta Mountains-Uinta Basin region (Mississippian)
Mississippian (3) sedimentary rocks in central Utah (Mississippian)
Mississippian (3) sedimentary rocks in western Utah (Mississippian)
Ordovician sedimentary rocks in Logan-Huntsville Allochthon (Ordovician)
Ordovician sedimentary rocks in central Utah (Ordovician)
Ordovician sedimentary rocks in western Utah (Ordovician)
Pennsylvanian and Permian sedimentary rocks in Salt Lake City-Coalville-Randolph region (Pennsylvanian to Permian)
Pennsylvanian and Permian sedimentary rocks in central Utah (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 western Utah (Pennsylvanian to Permian)
Pennsylvanian sedimentary rocks in Salt Lake City-Coalville-Randolph region (Pennsylvanian)
Pennsylvanian sedimentary rocks in central Utah (Pennsylvanian)
Pennsylvanian sedimentary rocks in western Utah (Mississippian to Pennsylvanian)
Permian (1) sedimentary rocks in central Utah (Early Permian)
Permian (1) sedimentary rocks in southeastern Utah (Pennsylvanian to Early Permian)
Permian (2) sedimentary rocks in Logan-Huntsville Allochthon (Permian)
Permian (2) sedimentary rocks in Salt Lake City-Coalville-Randolph region (Permian)
Permian (2) sedimentary rocks in central Utah (Permian)
Permian (2) sedimentary rocks in southeastern Utah (Early Permian)
Permian (2) sedimentary rocks in southwestern Utah (Early Permian)
Tertiary (1) sedimentary rocks in Salt Lake City-Coalville-Randolph region (Late Paleocene to Early Eocene)
Tertiary (1) sedimentary rocks in Uinta Mountains-Unita Basin region (Early to Middle Eocene)
Tertiary (1) sedimentary rocks in central Utah (Late Paleocene to Early Eocene)
Tertiary (1) sedimentary rocks in southeastern Utah (Late Paleocene to Early Eocene)
Tertiary (1) sedimentary rocks in southwestern Utah (Late Paleocene to Early Oligocene)
Tertiary (2) sedimentary rocks in Uinta Mountains-Uinta Basin region (Eocene)
Tertiary (2) sedimentary rocks in central Utah (Eocene)
Tertiary (2) sedimentary rocks in southwestern Utah (Eocene)
Tertiary (3) sedimentary rocks in southeastern Utah (Eocene)
Tertiary (4) sedimentary rocks in southeastern Utah (Late Eocene)
Triassic (1) sedimentary rocks in Logan-Huntsville Allochthon (Early Triassic)
Triassic (1) sedimentary rocks in Salt Lake City-Coalville-Randolph region (Early Triassic)
Triassic (1) sedimentary rocks in Salt western Utah (Early Triassic)
Triassic and Jurassic sedimentary rocks in southeastern Utah (Early Jurassic)
Upper Cambrian carbonate rocks in central Utah (Middle Cambrian to Early Ordovician)
Upper Cambrian carbonate rocks in western Utah (Middle Cambrian to Early Ordovician)
Younger Precambrian metamorphic rocks in central Utah (Proterozoic Z)

Virginia

Beekmantown Group (Ordovician): Beekmantown Group - Dolomite, limestone, and chert. Includes Pinesburg Station Dolomite, Rockdale Run Formation, Beekmantown Formation, Stonehenge Limestone, and Chepultepec Formation.
Bluefield Formation (Mississippian): Bluefield Formation - Calcareous shale and limestone.
Candler Formation - Lmestone (Cambrian): Candler Formation - Limestone.
Chepultepec and Copper Ridge Formations (Cambrian-Ordovician): Chepultepec and Copper Ridge Formations - Dolomite, minor limestone, chert, and calcareous sandstone.
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.
Edinburg Formation, Lincolnshire and New Market Limestones (Ordovician): Edinburg Formation, Lincolnshire and New Market Limestones - Black limestone and shale; gray limestone, in part cherty
Elbrook Formation (Cambrian): Elbrook Formation - Dolomite, shale, and minor limestone.
Everona Limestone (Cambrian): Everona Limestone - Limestone.
Frederick Limestone (Cambrian): Frederick Limestone - Limestone.
Greenbrier Limestone (Mississippian): Greenbrier Limestone - Limestone, in part cherty, fossiliferous; shale.
Hampshire Formation (Devonian): Hampshire Formation - Dusky-red to grayish-red shale, mudrock, and sandstone.
Hardy Creek Limestone through Dot Limestone (Ordovician): Hardy Creek Limestone through Dot Limestone - Limestone, in part cherty; and calcareous shale. Includes Hardy Creek, Ben Hur, Woodway, Hurricane Bridge, Martin Creek, Rob Camp, Poteet, and Dot Limestones.
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.)
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 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.
Lower Tertiary Deposits (Tertiary): Lower Tertiary Deposits - Glauconitic quartz sand and clay-silt, shelly in part, minor sandy limestone and limey sand; may include the following formations: Brightseat, Aquia, Marlboro, Nanjemay, and Piney Point (Pamunkey Group); and Old Church.
Mascot and Kingsport Dolomites (Ordovician): Mascot and Kingsport Dolomites - Dolomite, chert, and minor limestone.
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
Nolichucky and Maryville Formations, Rogersville Shale, and Rutledge Formation (Cambrian): Nolichucky and Maryville Formations, Rogersville Shale, and Rutledge Formation - Calcareous shale, limestone, and dolomite.
Ridgeley Sandstone, Helderberg and Cayugan Groups (Silurian-Devonian): Ridgeley Sandstone, Helderberg and Cayugan Groups - Calcareous sandstone; partly cherty limestone; calcareous shale; fossiliferous.
Shady Dolomite (Cambrian): Shady Dolomite - Dolomite.

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.
Chipman, Bridport, and Beldens Formations, Providence Island Dolomite; Beldens Member (Ordovician): Chipman, Bridport, and Beldens Formations, Providence Island Dolomite; Beldens Member - Interbedded buff to brown heavily scored dolomite and white to blue-gray marble and limestone; designated Beldens Formation east of Highgate Springs thrust.
Chipman, Bridport, and Beldens Formations, Providence Island Dolomite; Burchards Member (Ordovician): Chipman, Bridport, and Beldens Formations, Providence Island Dolomite; Burchards Member - Blue-gray limestone with irregular spots of light buff dolomite that give weathered surface a mottled appearance.
Chipman, Bridport, and Beldens Formations, Providence Island Dolomite; Weybridge Member (Ordovician): Chipman, Bridport, and Beldens Formations, Providence Island Dolomite; Weybridge Member - Gray limestone with thin interbeds of sandy limestone 1/2 to 2 inches thick and 1 to 4 inches apart.
Cumberland Head Formation (Ordovician): Cumberland Head Formation - Interbedded calcareous black shale and fine-grained homogenous, dark-gray limestone; shown only in Grand Isle County where it is thick enough and well enough exposed to map.
Fitch Formation (Silurian): Fitch Formation - Quartz-plagioclase-biotite granulite; actinolite-diopside granulite; impure limestone and dolomite; mica schist; the carbonate-rich beds are typically an inch or two thick and segmented so as to give the weathered outcrop a characteristic pitted appearance. (Southeastern Vermont).
Fitch Formation (Silurian): Fitch Formation - Bluish-gray, white-weathered, sandy limestone. (Northeastern Vermont).
Glens Falls Formation, Larrabee Member (Ordovician): Glens Falls Formation, Larrabee Member - Thin-bedded shaly limestone. (Glens Falls Formation: Thin bedded, dark blue-gray, rather coarsely granular and highly fossiliferous limestone.)
Glens Falls Formation, Shoreham Member (Ordovician): Glens Falls Formation, Shoreham Member - Interbedded limestone and shale, contains Cryptolithus tesselatus and Prasopora orientalis. (Glens Falls Formation: Thin bedded, dark blue-gray, rather coarsely granular and highly fossiliferous limestone.)
Glens Falls and Orwell Limestones, Undifferentiated (Ordovician): Glens Falls and Orwell Limestones, Undifferentiated - Combined where deformation has made the thin bedded Glens Falls undistinguishable from the thick bedded Orwell; from West Rutland south may contain rocks as low as the Middlebury.
Hatch Hill and West Castleton Formations, Undifferentiated (Cambrian): Hatch Hill and West Castleton Formations, Undifferentiated - The Hatch Hill, a relatively thin formation that succeeds the West Castleton, is characterized by rusty and spongy weathered gray calcareous quartzite traversed by numerous white-quartz viens. The West Castleton is a gray to black, siliceous, carbonaceous, and pyritiferous slate containing paper-thin white sandy laminae. Black slates are common to both formations. A blue-gray weathered black limestone is near the base of the West Castleton in a few places.
Highgate Formation (Ordovician): Highgate Formation - Banded blue limestone and calcareous slate; local lenses of limestone conglomerate; on west limb of St. Albans synclinorium.
Middlebury and Chazy Limestone, Undifferentiated Youngman and Carman Formations, Crown Point Member (Ordovician): Middlebury and Chazy Limestone, Undifferentiated Youngman and Carman Formations, Crown Point Member - Massive, characterized by abundant Maclurites magnus.
Middlebury and Chazy Limestone, Undifferentiated Youngman and Carman Formations, Valcour Member (Ordovician): Middlebury and Chazy Limestone, Undifferentiated Youngman and Carman Formations, Valcour Member - Dark gray calcarenite succeeded by medium to light gray, buff-weathered silty, partly coquinal limestone.
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.
Morses Line Formation (Ordovician): Morses Line Formation - Calcareous and non-calcareous slate; local lenses of thin-bedded limestone, limestone conglomerate, and dolomite; in St. Albans synclinorium.
Orwell Limestone and Isle la Motte and Lowville Limestones (Ordovician): Orwell Limestone and Isle la Motte and Lowville Limestones - Smooth ledged, sublithographic and lithographic, dove gray weathered limestone commonly cut by veins of white calcite; beds filled with fossil shell fragments are characteristic. The Lowville is a thin, undifferentieated unit near the base of the Orwell that is characteristically ashen gray and contains abundant Phytopsis tubulosum. The Isle La Motte is about the equivalent of the Orwell in areas west of Champlain thrust, on Isle La Motte and near South Hero, Highgate, Swanton, and St. Albans; it is locally underlain by the Lowville, which is too thin to show on map. The Sawyer Bay is herein defined as a member of the Lowville Formation of the Black River Group. Occurs approximately in the middle of the Lowville throughout the Champlain Valley and represents a significant deepening event. Lower part of the Lowville was deposited in a shallow lagoonal environment, while the Sawyer Bay was deposited in a subtidal normal marine environment. Deposition probably the result of high angle block faulting in the Champlain basin. Member is very dark gray to black micrite to sparite in composition with irregular "lumpy" bedding, wavy lamination, cross-lamination, and ripple marks. Irregularly shaped, scattered chert nodules are concentrated in specific horizons. Contains a few large and small brachiopods, trilobite fragments and some fossil hash. Member is approximately 6 ft thick at Sawyer Point, South Hero Island, northwestern VT; thins to 2 ft at Arnold Bay, and becomes an indistinct rubbly unit at Crown Point, northeastern NY. The Lowville, at Crown Point, also contains the House Creek Member. The House Creek is also present in northwestern NY, southern Ontario, and the Black River Valley, but is not seen at Sawyer Point or Arnold Bay. The Lowville reaches a maximum thickness of 50 ft at Crown Point and a minimum of 24 ft at Sawyer Point. The Lowville overlies the Pamelia Formation and underlies the Chaumont Formation. Age is Middle Ordovician (Blackriveran). (Bechtel and Mehrtens, 1995).
Shaw Mountain Formation (Silurian): Shaw Mountain Formation - Chiefly tan to brown weathered quartzose limestone and calcareous quartzite characterized by specks of limonite after ankerite; locally underlain by quartz conglomerate and overlain by blue fossiliferous crystalline limestone; greenstone and quartz-sericite schist.
Shelburne, Whitehall, and Strites Pond Formations (Ordovician): Shelburne, Whitehall, and Strites Pond Formations - The Shelburne is chiefly a white marble or gray limestone characterized by raised reticulate lines of gray dolomite on the weathered surface; includes Sutherland Falls marble, intermediate dolomite and Columbian marble of the marble quarries. Interbedded massive dolomite increases westward and predominates in the Whitehall formation, west of Champlain and Orwell thrusts. The Strites Pond, which is identical to the Shelburne, is east of Philipsburg thrust.
Stony Point Formation (Ordovician): Stony Point Formation - Predominantly calcareous black shale that grades upward into argillaceous limestone and rare dolomite beds, in northwestern Vermont.
Sweetsburg Formation, Rockledge Conglomerate Member (Cambrian): Sweetsburg Formation, Rockledge Conglomerate Member - Phenoclasts chiefly of biohermal limestone in a matrix of gray limestone containing frosted quartz sand grains.
Underhill Formation, Battell Member (Cambrian): Underhill Formation, Battell Member - Carbonaceous sericite-quartz-albite-chlorite schist and schistose quartzite, also carbonaceous and noncarbonaceous limestone; quartz-sericite-chlorite-albite schist. (Northern and Central Vermont). The Battell is raised to Formation rank by T.R. Armstrong (in press) [not in bibliography] to describe graphitic schists with carbonates that depositionally overlie the Monastery Formation in the Granville-Hancock area of central VT. The name Battell Formation is tentatively assigned in this report to a distinct group of graphitic rocks with limited occurrence in the study area. The basal portion of the Battell is assigned by Armstrong to the White River Member (new name) and following that nomenclature, the White River is the only part of the Battell seen in the Fayston-Buels Gore area. The White River appears to be in fault contact with the Underhill Formation along the eastern boundary of the Underhill in Buels Gore. The member also appears to be in depositional contact with the Monastery Formation at all observed locations and occurs as small bodies within the schists of the Monastery (Walsh, 1992).
Underhill Formation, Forestdale Member (Cambrian): Underhill Formation, Forestdale Member buff to rusty weathered sandy dolomite and limestone. (Northern and Central Vermont).
Underhill Formation, White Brook Member (Cambrian): Underhill Formation, White Brook Member - Chiefly brown-weathered whitish, tan and gray sandy dolomite, locally only a hematitic zone; includes carbonaceous crystalline limestone in Cambridge syncline. (Northern and Central Vermont).
Waits River Formation (Devonian): Waits River Formation - Gray quartzose and micaceous crystalline limestone weathered to distinctive brown earthy crust; interbedded and intergradational with gray quartz-muscovite phyllite or schist. Where more metamorphosed the limestones contain actinolite, hornblende, zoisite, diopside, wollastonite, and garnet, and the phyllite and schist, biotite, garnet, and locally andalusite, kyanite or sillimanite.
Waits River Formation, Ayers Cliff Member (Devonian): Waits River Formation, Ayers Cliff Member - Siliceous crystalline limestone containing thin beds of slate and phyllite north of the Lamoille River.
Waits River Formation, Barton River Member (Devonian): Waits River Formation, Barton River Member - Interbedded siliceous crystalline limestone and sercite-quartz-chlorite phyllite in northern Vermont; diopsidic limestone and cordierite hornfels at contacts with granitic dikes and sills.

Washington

Cambrian limestone and dolomite (Early Cambrian-Middle Ordovician): Mostly massive dolomite, with a basal unit of gray to dark-gray limestone interbedded with limy shale, and an upper unit of fine-grained massive limestone with some marble; Pend Oreille and northern and central Stevens Counties. Three-fold division less evident in Colville area. Dolomite, with minor basal unit of interbedded limestone and phyllite in the Addy-Dunn Mountain area of Stevens County. Marble, dolomite, limestone, and limy slate in Hunters' district. Dolomitic marble in southern Stevens and northern Lincoln Counties. Middle Cambrian fossils near base in Metaline district, and Bathyuriscus-Elrathina fauna in lower unit in Leadpoint district. Phosphatic brachiopods in upper unit in Leadpoint district tentatively assigned to Middle and Upper Cambrian.
Devonian rocks (Devonian to Permian): Thin alternating beds of cherty quartzite and argillite, occasional limestone lenses, volcanic rocks, sandstone, and graywacke on northwest shore of Orcas Island. Small outcrops of Devonian limestone included under Pzu in southeastern Stevens County and under PMPms 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.

Wisconsin

Ancell Group (Ordovician): Ancell Group - Orthoquartzitic sandstone with minor limestone, shale and conglomerate; includes Glenwood and St. Peter Formations
Sinnipee Group (Ordovician): Sinnipee Group - Dolomite with some limestone and shale; includes Galena, Decorah, and Platteville Formations
Traverse Group (Middle Devonian): Traverse Group

West Virginia

Beekmantown or Lower Ordovician Group (Ordovician): Beekmantown or Lower Ordovician Group - mainly thick-bedded limestone and dolomite. Various units produce much chert on outcrop. Consists of units: Pinesburg Station Dolomite, Rockdale Run Formation, and Stonehenge Limestone.
Black River Group (Ordovician): Black River Group - predominantly gray aphanitic limestones, with many bioclastic streaks; siliceous in the lower part.
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.
Conococheague Formation (Cambrian): Conococheague Formation - predominantly algal and mechanically deposited limestone, with interbeds of aphanitic limestone and dolomite. Contains siliceous and dolomitic laminations. Resistant sandy Big Spring Station Member near the base.
Elbrook Formation (Cambrian): Elbrook Formation - thin-bedded blue-gray argillaceous limestone and platy shale, with some siliceous limestone and minor dolomite.
Greenbrier Group (Mississippian): Greenbrier Group - marine limestone and marine and non-marine red and gray shale, and minor sandstone beds in numerous formational units.
Harrell Shale (Devonian): Harrell Shale (part of Millboro Shale) - dark gray to black thinly laminated to fissile shale. Calcareous shale and limestone lenses near the base (Tully).
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.
Marcellus Formation (Devonian): Marcellus Formation (part of Millboro Shale) - predominantly gray-black to black thinly laminated non-calcareous pyritic shale. Contains one or more thin-bedded limestones, including the Purcell Member 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.
Ordovician, middle calcareous units (Ordovician): Ordovician - middle calcareous units.
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.
Rockdale Run Formation (Ordovician): Rockdale Run Formation - bluish to light gray and brown, thick-bedded dolomite and limestone, containing gray chert and zones of Cryptozoa and Lecanospira.
St. Paul Group (Ordovician): St. Paul Group - includes the New Market and Row Park Limestones. Predominantly medium-gray aphanitic limestone, containing very low-silica, cream-colored member of considerable economic importance. Chert nodules and dolomite occur in the Row Park.
Stonehenge Limestone (Ordovician): Stonehenge Limestone - gray, thin-bedded to massive, fossiliferous limestone, largely mechanically deposited, with small black chert nodules and beds of "edgewise" conglomerate. The highly resistant Stoufferstown Limestone member is found at the base.
Tomstown Dolomite (Cambrian): Tomstown Dolomite - thick-bedded, blue-gray, aphanitic, saccharoidal, and splintery dolomite, weathering coffee-brown; some siliceous limestone and black chert. Contains commercial beds of white, pure, low-silica dolomite.
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.
Trenton Group (Ordovician): Trenton Group - dark, crystalline, nodular, and argillaceous limestones, with some metabentonite streaks. Includes the Nealmont, Oranda, Edinburg, and the upper part of the Chambersburg Limestones of northeastern West Virginia; also the Moccasin and Eggleston Formation of Mercer and Monroe Counties.
Trenton Group and Black River Group, undivided (Ordovician): Trenton Group and Black River Group, undivided - Trenton Group: dark, crystalline, nodular, and argillaceous limestones, with some metabentonite streaks. Includes the Nealmont, Oranda, Edinburg, and the upper part of the Chambersburg Limestones of northeastern West Virginia; also the Moccasin and Eggleston Formation of Mercer and Monroe Counties. Black River Group: predominantly gray aphanitic limestones, with many bioclastic streaks; siliceous in the lower part.

Wyoming

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 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.
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.
Chugwater and Dinwoody Formations (Phanerozoic | Mesozoic | Triassic-Early Triassic-Middle(?) Triassic-Late): CHUGWATER AND DINWOODY FORMATIONS. CHUGWATER FORMATION--Red siltstone and shale. Alcova Limestone Member in upper middle part. Thin gypsum partings near base. DINWOODY FORMATION--Olive-drab hard dolomitic thin-bedded siltstone.
Forelle Limestone and Satanka Shale (Phanerozoic | Paleozoic | Permian): FORELLE LIMESTONE AND SATANKA SHALE. FORELLE LIMESTONE--Thin-bedded limestone. Locally is a member of the Goose Egg Formation. SATANKA SHALE--Red shale .
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.
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.
Madison Group and Darby Formation (TB, N) or Madison Group and Three Forks and Jefferson Formations (Y) (Phanerozoic | Paleozoic | Devonian-Late Carboniferous Mississippian-Early(?) Mississippian-Middle(?) Mississippian-Late): MADISON GROUP AND DARBY FORMATION (Thrust Belt, north Wyoming). 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. MADISON GROUP AND THREE FORKS AND JEFFERSON FORMATIONS (Yellowstone). MADISON GROUP--Group includes Mission Canyon Limestone (blue-gray massive limestone and dolomite), underlain by Lodgepole Limestone (gray cherty limestone and dolomite). THREE FORKS FORMATION--Pink, yellow, and green dolomitic siltstone and shale. JEFFERSON FORMATION--Massive siliceous dolomite.
Madison Limestone and Bighorn Dolomite (Phanerozoic | Paleozoic | Ordovician-Middle Ordovician-Late(?) Silurian(?) Devonian(?) Carboniferous Mississippian-Early(?) Mississippian-Middle(?) Mississippian-Late): MADISON LIMESTONE AND BIGHORN DOLOMITE. MADISON LIMESTONE OR GROUP--Group includes Mission Canyon Limestone (blue-gray massive limestone and dolomite), underlain by Lodgepole Limestone (gray cherty limestone and dolomite). BIGHORN DOLOMITE--Light-gray massive siliceous dolomite.
Madison Limestone or Group (S) (Phanerozoic | Paleozoic | Carboniferous Mississippian-Early Mississippian-Middle(?) Mississippian-Late): MADISON LIMESTONE OR GROUP--Group includes Mission Canyon Limestone (blue-gray massive limestone and dolomite), underlain by Lodgepole Limestone (gray cherty limestone and dolomite).
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).
Minnekahta Limestone and Opeche Shale (Phanerozoic | Paleozoic | Permian): MINNEKAHTA LIMESTONE AND OPECHE SHALE. 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 (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.
Niobrara Formation (Phanerozoic | Mesozoic | Cretaceous-Late): NIOBRARA FORMATION (AGE ABOUT 83 Ma)--Light-colored limestone and gray to yellow speckled limy shale.
Niobrara Formation and Carlile Shale (Phanerozoic | Mesozoic | Cretaceous-Late): NIOBRARA FORMATION (Kn) AND CARLILE SHALE (Kcl). NIOBRARA FORMATION (AGE ABOUT 83 Ma)--Light-colored limestone and gray to yellow speckled limy shale. CARLILE SHALE--Dark-gray sandy shale; Sage Breaks Member at top; Turner Sandy Member in middle.
Pahasapa and Englewood Limestones (Phanerozoic | Paleozoic | Devonian-Late Carboniferous Mississippian-Early): PAHASAPA AND ENGLEWOOD LIMESTONES. PAHASAPA LIMESTONE--Gray massive dolomitic limestone. ENGLEWOOD LIMESTONE--Pink slabby dolomitic limestone.
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.
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.
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).

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