Geologic units in Hawkins county, Tennessee

Additional scientific data in this geographic area

Sevier Shale (Ordovician) at surface, covers 27 % of this area

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.

Maynardville Limestone, Nolichucky Shale, Honaker Dolomite, Maryville Limestone, Rogersville Shale, Rutledge Limestone, Pumpkin Valley Shale (Cambrian) at surface, covers 10 % of this area

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.

Bays Formation (Ordovician) at surface, covers 8 % of this area

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.

Copper Ridge Dolomite (Ordovician) at surface, covers 6 % of this area

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.

Martinsburg Shale, including Reedsville Shale and Unnamed Limestone Unit (Ordovician) at surface, covers 6 % of this area

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.

Rome Formation (Cambrian) at surface, covers 5 % of this area

Variegated (red, green, yellow) shale and siltstone; gray, fine-grained sandstone in middle and west part of Valley and Ridge; abundant limestone and dolomite in east. Thickness about 2,000 feet.

Newala Formation, including Mascot Dolomite and Kingsport Formation (Ordovician) at surface, covers 4 % of this area

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.

Clinch Sandstone (Silurian) at surface, covers 4 % of this area

Clean, white, well-sorted sandstone; locally gray siltstone and shale. Average thickness about 600 feet.

Chattanooga Shale (Mississippian and Devonian) at surface, covers 4 % of this area

Black carbonaceous shale, fissile. Thickness 100 to 900 feet; about 25 feet on Chilhowee Mountain. (Mapped with Mfp on West-Central and parts of East Central Sheets)

Middle and Lower Parts of Chickamauga Group, including Mocassin Formation, Bays Formation, Sevier Shale, Ottosee Shale, Holston Formation, Lenoir Limestone and Athens Shale (Ordovician) at surface, covers 3 % of this area

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.

Newman Limestone (Mississippian) at surface, covers 3 % of this area

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.

Grainger Formation (Mississippian) at surface, covers 3 % of this area

Gray to green shale with siltstone and fine-grained glauconitic sandstone; in some areas quartz-pebble conglomerate. Thickness 500 to 1,000 feet.

Conasauga Group (Cambrian) at surface, covers 3 % of this area

Mostly shale northwest of a line connecting Knoxville and Tazewell; dominantly dolomite with minor shale southeast of a line from Newport to Kingsport; between these lines it consists of six formations. Thickness about 2,000 feet.

Chepultepec Dolomite (Ordovician) at surface, covers 3 % of this area

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.

Maryville Limestone, Rogersville Shale, Rutledge Limestone (Cambrian) at surface, covers 2 % of this area

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.

Jonesboro Limestone, Newala Formation, Mascot Dolomite, Kingsport Formation, Longview Dolomite, and Chepultepec Dolomite (Ordovician) at surface, covers 2 % of this area

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.

Pennington Formation (Mississippian) at surface, covers 2 % of this area

Highly variegated clay shale distinctive; contains siltstone beds and locally gray, fine-grained sandstone. Thickness 300 to 500 feet near Cumberland Plateau; maximum of about 1,250 feet to the east.

Maynardville Limestone (Cambrian) at surface, covers 1 % of this area

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.

Longview Dolomite (Ordovician) at surface, covers 1 % of this area

Siliceous, gray, fine-grained, medium-bedded dolomite; interbeds of gray limestone in upper part. Thickness about 300 feet.

Juniata Formation (Ordovician) at surface, covers 0.9 % of this area

Maroon, claystone, siltstone, and shale; uniformly bedded; some faint greenish mottling; less calcareous than Sequatchie Formation. Thickness about 300 feet.

Chickamauga Group (Ordovician) at surface, covers 0.8 % of this area

In the northwest predominantly a limestone sequence about 2,000 feet thick. Becomes progressively more clastic and thicker to the southeast.

Knox Group (Ordovician to Cambrian) at surface, covers 0.4 % of this area

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.

Nolichucky Shale (Cambrian) at surface, covers 0.3 % of this area

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.

Pumpkin Valley Shale (Cambrian) at surface, covers 0.2 % of this area

Dull-brown to maroon shale with numerous interbeds of thin, blocky, and sandy siltstone. Thickness 100 to 600 feet.

Longview Dolomite and Chepultepec Dolomite (Ordovician) at surface, covers 0.1 % of this area

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.

Nolichucky and Honaker Formations (Cambrian) at surface, covers < 0.1 % of this area

Nolichucky Formation. Refer to description under [nmrr]. Honaker Formation (Campbell, 1897). Dolostone, limestone, and shale. Dolostone, light- to dark-gray to dark-bluish-gray, aphanic to coarse-grained, thin- to massive-bedded, "butcher-block" weathering; with sparse interbeds of argillaceous limestone, and minor dark-gray chert. Limestone, argillaceous, ribbon-banded in part, light- to medium-gray, very-fine-grained, thick-bedded. Shale, greenish-gray, laminated to thin-bedded. The Honaker Formation is predominantly dolostone with subordinate limestone. The dolostone becomes more dominant in the northeastern part of outcrop belt (Evans and Troensegaard, 1991). Shale is locally present as a 20- to 60-feet-thick unit in the middle of the formation and as thin interbeds with the dolostone and limestone throughout the area. The Honaker Formation ranges from about 1000 to 1100 feet in thickness. It is laterally equivalent to the lower Elbrook to the east.

Pennington Group (Mississippian) at surface, covers < 0.1 % of this area

Pennington Group (Campbell, 1893). Bluestone Formation, Princeton Sandstone, and Hinton Formation. Raised to Group rank by Harris and Miller (1958). The group consists of shale, sandstone, mudstone, conglomerate, siltstone, minor limestone, and coal locally. The shale, siltstone, and mud stone are gray to black and shades of red, and mottled red and gray. The sandstone is locally quartzose and conglomeratic, and ranges from shades of gray to brown, and only locally mottled within red shales; many sandstones pinch out southwestward in the Tazewell County area, but two persist farther west and southwest. The limestone is gray to brown, generally near the middle of the group, and is the most widespread marine unit. The Bluestone and Hinton For ma tions thin to the westsouthwest in southwestern Virginia; the widespread sandstone and limestone members nearly converge southwestward to with in 80 feet of each other from about 600 feet of separation in northern Tazewell County. The Princeton Sandstone wedges out in Tazewell County. The top of the Pennington Group is intertonguing to unconform ble with the overlying Lee Formation in the western part of the Southwest Virginia coalfield; basal contact is conformable. The Group thins westward; variation in thickness partly due to intertonguing and the unconformity. The Pennington Group ranges from 235 feet in thickness without the Pinacle Overlook Member of the Lee (as interpreted from Vanover and others, 1989) in the south west to 2355 feet (Trent and Spencer, 1990) in Tazewell County and 1335 feet in a partial section in Washington County (Bartlett and Webb, 1971), where it is mapped as the Pennington Formation. Bluestone Formation (Campbell, 1896). Sand stone, siltstone, shale, mudstone, minor limestone, coal, and underclay. Sand stone, argillaceous, micaceous, locally quartzose, verylight to dark-gray, light-olive- to greenish-gray, yellowish-orange to dark-yellowish-brown, moderate-red, very-fine- to medium-grained, thin- to very-thick-bedded, cross-bedded, locally ripple-bedded, interbedded with shale and siltstone; forms ledges and cliffs. Sand stone in middle of formation in Scott and Russell counties is conglomeratic with quartzite pebbles and other rock clasts (Evans and Troensegarrd, 1991; Nolde and Diffenbach, 1988). Upper part intertongued with Lee in northern Lee County (Miller and Roen, 1973). Siltstone, shale, and mudstone, partly calcareous, greenish-gray, dark gray to grayish-black, pale- to moderate-red and mottled red and greenish-gray; siderite nodules in variegated shales and silt stones; fossils in dark-gray shale (Englund, 1968). Limestone, argillaceous, medium-gray, thin, lenticular, fossiliferous, in middle of formation, and in thin discontinuous beds at the base of the formation in the sub sur face in western Tazewell and eastern Buchanan Counties (Englund, 1981). Thin coal bed in upper part of formation in northern Lee County (Miller and Roen, 1973); coal and impure coal in thin discontinuous beds in middle of formation in northern Tazewell County; underlain by underclay, locally as much as three feet thick, with root casts (Englund, 1968). Top un con form able with the overlying Lee Formation in northwestern Wise and Dickenson counties and extreme northwestern Buchanan County but is intertonguing to the southeast (Mill er, 1974) and southwest in northern Lee County (Miller and Roen, 1973). Base conformable with the underlying Princeton Sandstone in northern Tazewell County, but is disconformable to the southwest because the Princeton wedges out southwestward in Tazewell County and the Bluestone lies on the Hinton Formation (Englund and Thomas, 1990). Bluestone thins northwestward and ranges in thickness from 40 feet in southwestern Lee County (Englund, Landis, and Smith, 1963) to as much as 850 feet to the northeast in Tazewell County (Englund and Thomas, 1990). Princeton Sandstone (Campbell and Mendenhall, 1896). Sandstone, light-gray to light-greenish-gray, weathered locally to pale-reddish-brown, fine- to coarse-grained, thin- to very thick- bedded, locally cross-bedded, calcite cemented, becomes friable upon weathering, contains conglomerate lenses as much as two feet thick with well-rounded to angular pebbles of quartz, shale, silt stone, limestone, chert, and ironstone; fossils in limestone clasts (Englund, 1968, 1979; Trent and Spencer, 1990). Wedges out southwestward in west-central Tazewell County (Englund, 1979). The Princeton as mapped in Lee County and southwestern Scott County (Harris and Miller, 1958; Miller and Roen, 1973) is a different sandstone. The Princeton ranges from 0 to 60 feet in thickness. Hinton Formation (Campbell and Mendenhall, 1896). Shale, siltstone, mudstone, sandstone, limestone, minor coal, underclay. Shale, siltstone, and mudstone, partly calcareous, grayish-red, medium-gray, and greenish-gray, fossiliferous. Sandstone, quartzose, feldspathic, very-light- to medium-light gray, greenish-gray, yellowish-brown, pale- to moderate-red, locally mottled, very-fine- to medium-grained, thin- to very thick- bedded, contains quartz-pebble con lomerate, tree trunk impressions, and coal fragments; cobbles in lowest member locally; interbedded with dark-gray to grayish-black shale. A widespread conglomeratic sandstone in the upper part of the formation has been misidentified as the stratigraphically higher Princeton Sandstone (Englund, 1979). Limestone, argillaceous, light-grayish-brown, medium-gray, thin-bedded, nodular, very fossiliferous, contains marine fossils of Chesterian age and is most widespread marine unit (Little Stone Gap Member) in the Hinton (Englund, 1979). Base conformable. The formation ranges from 164 feet in thickness in southwestern Lee County to 1320 feet in northern Tazewell County (Englund, 1968, 1979).

Rome Formation (Cambrian) at surface, covers < 0.1 % of this area

Pumpkin Valley Shale and Rome Formation. Pumpkin Valley Shale (Bridge, 1945). Shale, light-greenish-gray to dark-greenish-gray, grayish-brown, and maroon; a few beds of similar colored siltstone; sparse beds of limestone and dolostone. The Pumpkin Valley Shale conformably overlies the Rome Formation. The formation is approximately 350 feet thick. Harris (1964) identified the Pumpkin Valley Shale of Southwest Virginia as a formation within the Conasauga Group; however, because of similar lithologies it is often indistinguishable from the Rome Formation and the two formations commonly are mapped together. Rome Formation (Hayes, 1891). Siltstone, shale, sandstone, dolostone, and limestone. Siltstone and shale, greenish-gray and grayish-red, laminated to thin-bedded. Sandstone, micaceous, locally glauconitic, greenish-gray and reddish-gray, very-fine- to medium-grained, thin-bedded. Dolostone, light- to dark-gray, aphanic to medium-grained, thin-to massive-bedded, with ripple marks and mudcracks. Lime stone, argillaceous, very-light-gray to dark-gray, thin- to medium- bedded. Carbonate rocks range from sparse 1- to 2- feet-thick beds in western Scott County to discontinuous units as much as 50 feet thick which comprise 30 to 40 percent of the formation in western Russell and Washington counties (Evans and Troensegaard, 1991; Bartlett and Webb, 1971). Maximum recorded thickness is 1500 feet in the Clinchport area (Brent, 1963); although this may have included the Pumpkin Valley Shale. A complete thickness has not been determined because the lowermost part of the Rome Formation is normally absent due to faulting.

Brallier Formation (Devonian) at surface, covers < 0.1 % of this area

Brallier Formation (Butts, 1918). Shale, sandstone, and siltstone. Shale, partly silty, micaceous, greenish-gray, gray ish-brown and medium- to dark-gray, black, weathers light-olive-gray with light-yellow, brown and purple tints; black shale in thin beds and laminae, sparsely fossiliferous. Sandstone, micaceous, medium-light-gray, very-fine- to fine-grained, thin- to thick-bedded, and light-brown siltstone interbedded with shale. Locally siltstone is in very-thin, nodular, ferruginous lenses (Bartlett, 1974). Lower contact transitional; base at lowest siltstone bed above relatively nonsilty dark-gray shale. Equivalent to part of the Chattanooga Shale. Formation thins southwestward; it ranges from 940 feet in thickness in southwestern Washington County (Bartlett and Webb, 1971) to more than 2200 feet in Augusta County (Rader, 1967).

Greenbrier Limestone (Mississippian) at surface, covers < 0.1 % of this area

Greenbrier Limestone (Rogers, in Macfarlane, 1879). Limestone, dolomite, and minor shale. Limestone, very-light olive-to olive-gray and brownish-gray, and medium- to dark gray, micrograined to coarse-grained, thin- to thick- bedded, thinner bedded in upper part, even- to cross-bedded; few shaly beds in upper part; oolitic in upper part and in cross-laminated beds near base; black chert near middle of formation, gray to pale-red near base; very fossiliferous. Pale-brown dolomite near upper chert zone, minor dolomite locally in lower part. Few interbeds of greenish-gray and grayish-red, calcareous, silty shale. Limestone is petroliferous locally in upper part (Henika, 1988). Base locally unconformable with underlying Maccrady Shale. Formation thickens to east, ranging from 200 feet in western Wise County to 3500 feet in Washington nd Scott counties. The Greenbrier is equivalent to (descending): Gasper Limestone, Ste. Genevieve Limestone, St. Louis Limestone (Hillsdale Limestone), and Little Valley Limestone (Warsaw equivalent), and to lower part of the Newman Limestone (Butts, 1940; LeVan and Rader, 1983). Newman Limestone (Campbell, 1893). Limestone and shale. Limestone, light-olive-gray in lower half, medium-gray to olive-gray in upper half, aphanic to fine-grained, partly oolitic, partly argillaceous, with basal beds of dark-gray chert nodules and local dolomite. Shale, medium-gray to medium dark-gray, partly calcareous, interbedded with limestone in upper half of unit. The Newman Limestone ranges from 550 to 600 feet in thickness and is equivalent to the Bluefield Formation and Greenbrier Limestone. Fort Payne Chert. (Smith, in Squire, 1890). Greenish gray chert in thin beds (2 - 6 inches thick); with shale partings. The Fort Payne Chert ranges from 0 to 20 feet in thickness and pinches out to the northeast. Grainger Formation (Campbell, 1893). Shale, pale-olive or greenish-gray to dark-greenish-gray, locally gray ish-red in lower half and at top; with some interbedded pale-olive-gray siltstone and very-fine-grained sandstone, locally abundant siderite nodules near base. The Grainger Formation ranges from 250 to 325 feet in thickness and is the lateral equivalent of the Maccrady Shale and Price Formation.

Cove Creek Limestone and Fido Sandstone (Mississippian) at surface, covers < 0.1 % of this area

Cove Creek Limestone (Butts, 1927). Limestone, argillaceous, light-gray to greenish-gray, thin- to thick-bedded, vsparsely fossiliferous, with thin, brownish laminae; thin beds and zones of medium- to coarse-grained, calcareous sandstone locally present. The Cove Creek Limestone ranges from 1010 to 1220 feet in thickness (Averitt, 1941; Bartlett and Webb, 1971). Fido Sandstone (Butts, 1927). Sandstone, calcareous, reddish-brown to dark-brown, fine- to coarse-grained, thick bedded, cross-bedded, and ripple-marked, fossiliferous, with one or more beds of argillaceous limestone. The Fido Sandstone ranges from 35 to 75 feet in thickness (Averitt, 1941; Bartlett and Biggs, 1980).

Silurian Formations Undivided (Silurian) at surface, covers < 0.1 % of this area

Some landslides with intact stratigraphic units in Giles County area. Includes: Dsu, Skrt, Sm. (Shrc?)

Maccrady Shale and Price Formation (Mississippian) at surface, covers < 0.1 % of this area

Maccrady Shale and Price Formation. Refer to individual units for descriptions.