Geologic units in Letcher county, Kentucky

Additional scientific data in this geographic area

Breathitt Formation, lower part (Pennsylvanian) at surface, covers 72 % of this area

lower part which includes Livingston Conglomerate Member of Lee Formation in eastern Rockcastle County

Breathitt Formation, middle part (Pennsylvanian) at surface, covers 18 % of this area

Breathitt Formation, middle part

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) at surface, covers 4 % of this area

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

Lee Formation (Mississippian to Pennsylvanian) at surface, covers 4 % of this area

Lee Formation

Chattanooga and Ohio Shales, undivided (Devonian to Mississippian) at surface, covers 1 % of this area

Chattanooga and Ohio Shales, undivided; along and south of the Pine Fault

Wise Formation (Pennsylvanian) at surface, covers 0.2 % of this area

Wise Formation (Campbell, 1893) . Sandstone, siltstone, shale, limestone, coal, and underclay. Sandstone, lithic, feldspathic, micaceous, argillaceous, carbonaceous locally, light- to medium-gray to moderate- and pale-yellow- brown, fine- to coarse-grained, locally pebbly, thin- to thick-bedded, cross-bedded to even-bedded, locally massive, well-cemented; contains fragments of shale, siltstone, and carbonized plant fossils locally. Siltstone and shale, light olive- gray, medium- to dark-gray and grayish-black, contains siderite ironstone in very-thin beds and nodules, carbonized plant fossils; invertebrate fossils in dark-gray to black shale and micrograined limestone in the upper part of formation (Miller, 1969; Miller and Roen, 1973; Nolde, Henderson, and Miller,1988; Nolde, Whitlock, and Lovett, 1988a). Limestone, medium- to dark-gray, micrograined, in very-thin lenses and beds in shale and siltstone in two to three zones in lower part of formation (Taylor, 1989; Whitlock, Lovett, and Diffenbach, 1988). Coal interbedded with shale, siltstone, and sandstone. Underclay, light-gray, root casts, beneath coal; as much as 5 feet thick under the Williamson coal bed in Buchanan County (Henika, 1989b). A dark-gray to brownish-gray, flint clay in the Phillips (Fire Clay; No.7) coal bed in northern Lee County (Miller and Roen, 1973) and western Wise County is a volcanic ash deposit (Seiders, 1965) that covers parts of Kentucky, Tennessee, Virginia and West Virginia; it has been dated at an age of 311 - 312 million years (Lyons and others, 1992; Rice and others, 1990). Base of formation at bottom of Dorchester coal bed. Thickness 2150 to 2268 feet.

Lee Formation (Pennsylvanian) at surface, covers < 0.1 % of this area

Lee Formation (Campbell, 1893). Quartzarenite, conglomerate, sandstone, shale, siltstone, and coal. Quartzarenite, white, very-light- to light-gray, fine- to coarse-grained, locally conglomeratic, quartz-pebble conglomer te lenses, cross-bed ded, channel-fill deposits. Sandstone, feldspathic, micaceous, light-gray, fine- to medium-grained. Shale and siltstone, medium-dark-gray to dark-gray, interbedded; coal in several beds and zones. The quartzarenites terminate eastward by intertonguing and grading into finer grained and less quartzose rocks (Englund and DeLaney, 1966). Miller and Roen (1973) believe the lower three quartzarenites are Mississippian and intertongue with the Pennington Group. These die out northeastward from southwestern Lee County (Mill er, 1969). The quartzarenites in the upper part of the Lee tongue out or grade into fi ner clastic rocks of the Norton and Pocahontas Formations successively from highest to lowest southeastward (Englund, 1979; Miller, 1974). These quartzarenites consist of five tongues in northern Buchanan County (Lovett and others, 1992); but to the east only the lowest tongue exists (Whitlock, 1989; Nolde, 1989), and that grades eastward into sandstone in the New River Formation in eastern Buchanan, northeastern Russell, and western Tazewell counties. Formerly rocks east of the quartzarenites were considered Lee (Harnsberger, 1919; Virginia Division of Mineral Resources, 1963), but now are designated New River Formation (Englund, 1981) and correlative to the lower part of the Norton Formation. The Lee Formation thickens and truncates progressively older rocks northwestward (Miller, 1974). The intertonguing and unconformable relationship accounts for the great range in thickness for the Lee Formation. It ranges in thickness from 0 in southern Buchanan County (Meissner and Miller, 1981), to 1680 feet in Lee County (Miller and Roen, 1973).

Harlan Sandstone (Pennsylvanian) at surface, covers < 0.1 % of this area

Harlan Sandstone (Campbell, 1893) Sandstone, siltstone, shale, and coal. Sandstone, feldspathic, moderately quartzose, argillaceous, medium-gray, fine- to coarse-grained, thin- to thick-bedded, cross-bedded; quartzose sandstone is pebbly, moderately resistant, cliff-forming, and in lenticular bodies at base of formation where it fills channels (Miller, 1969; Miller and Roen, 1973). Sandstone comprises as much as 48 percent of formation. Siltstone and shale, medium- to dark-gray and brown, locally reddish-brown; contains 22 discontinuous coal beds. Miller (1969) changed the name from Harlan Sandstone (Campbell, 1893) to Harlan Formation because of the heterogeneous lithology and defined the base as the top of the High Splint coal bed. It is as much as 650 feet thick in northern Lee and western Wise counties, adjacent to Kentucky; upper part removed by erosion in Virginia (Miller and Roen, 1973; Nolde, Henderson, and Miller, 1988; Nolde, Whitlock, and Lovett, 1988a).

Breathitt Formation, upper part (Pennsylvanian) at surface, covers < 0.1 % of this area

Breathitt Formation, upper part

Norton Formation (Pennsylvanian) at surface, covers < 0.1 % of this area

Norton Formation (Campbell, 1893). Siltstone, shale, sandstone, conglomerate, limestone, and coal. Siltstone and shale, light- to medium-gray, with siderite and claystone concretions, fossiliferous; interbedded with and grades into sandstone. Sandstone, feldspathic, micaceous, argillaceous, light- to medium-gray, very-fine- to coarse-grained, thin- to very-thick-bedded, cross-bedded, locally massive, well-cemented. Conglomerate in thin zones in McClure Sandstone Member (lateral equivalent to part of Bee Rock Sandstone Member of the Lee Formation). Lime stone, medium-gray, micrograined, locally in lenses in two zones above the McClure Sandstone Member (Taylor, 1989; Whitlock, 1989). Coal in several beds and zones. A volcanic ash parting is in the Upper Banner coal bed locally (Diffenbach, 1988, 1989; Evans and Troensegaard, 1991; Henika, 1989a). The base of the Norton is defined as the top of the uppermost quartzarenite of the Lee Formation. On the western side of the coalfield the base of the Norton is at the top of the Bee Rock Sandstone Member of the underlying Lee Formation. However, the Bee Rock grades eastward into feldspathic, conglomeratic sandstone of the McClure Sandstone Member of the Norton. Several underlying Lee quartzarenites successively tongue out or grade into finer-grained clastic rocks to the southeast stratigraphically lowering the base of the Norton. This accounts for the great range in thickness of 500 to 2480 feet for the Norton Formation.

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).