Geologic units in McDowell county, West Virginia

Additional scientific data in this geographic area

New River Formation (Pennsylvanian) at surface, covers 63 % of this area

(part of Pottsville Group) - predominantly sandstone, with some shale, siltstone, and coal. Grades to nearly all sandstone in the subsurface. Extends from the top of the Upper Nuttall Sandstone to the top of the Flattop Mountain Sandstone. Includes the Iaeger, Sewell, Welch, Raleigh, Beckley, Fire Creek, and Pocahontas Nos. 8 and 9 coals.

Pocahontas Formation (Pennsylvanian) at surface, covers 19 % of this area

(part of Pottsville Group) - sandstone, approx. 50%, with some shale, siltstone, and coal. Extends from the top of the Flattop Mountain Sandstone to the top of the Mississippian. Includes from bottom upward Pocahontas coals Nos. 1 through 7.

Kanawha Formation (Pennsylvanian) at surface, covers 14 % of this area

(part of Pottsville Group) - sandstone (approx 50%), shale, siltstone, and coal. Contains several marine zones. Becomes more shaly westward in the subsurface. Extends from the top of the Homewood Sandstone to the top of the Upper Nuttall Sandstone. Includes the Stockton (Mercer), Coalburg, Winifrede, Chilton, Williamson, Cedar Grove, Alma, Peerless, Campbell Creek, Powellton, Eagle, Gilbert, and Douglas coals.

Bluestone and Princeton Formations (Mississippian) at surface, covers 3 % of this area

(part of Mauch Chunk Group) - the Bluestone Formation is mostly red, green, and medium-gray shale and sandstone; Princeton Sandstone is underneath.

Norton Formation (Pennsylvanian) at surface, covers 0.2 % 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.

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

New River Formation (Fontaine, 1874; redefined by Read and Mamay, 1964). Sandstone, siltstone, shale, coal, underclay, and limestone. Sandstone, feldspathic, micaceous, disseminated dark mineral grains, light- to medium-light-gray, very-fine- to coarse-grained, locally conglomeratic with quartz pebbles as much as 3 inches in diameter, thin- to thick-bedded, locally massive, ripple-bedded, cross-bedded; contains carbonaceous fragments. Siltstone, medium-light- to medium-gray, even-bedded, ripple-bedded, deformed locally. Shale, medium- gray to black, evenly to indistinctly bedded, with few very fissile carbonaceous beds, plant fossils, ironstone laminations and concretions. Coal, finely cleated, impure coal partings in several beds, locally grades into black carbonaceous shale. Underclay, medium-gray, clayey to silty, contains root casts. Limestone, medium-gray, argillaceous, in thin discontinuous beds and ellipsoidal concretions locally occurs near base and middle part of formation. Marine invertebrate fossils locally in basal bed. Base is conformable with Pocahontas Formation and placed at bottom of Pocahontas No. 8 coal bed in most outcrop areas (Englund and Thomas, 1990). Northwest of outcrop belt, base is unconformable with the underlying Pocahontas Formation. The New River is thickest in western Tazewell and eastern Buchanan counties (Englund, 1981); it ranges from 1380 to 1925 feet in thickness.

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

Pocahontas Formation (Campbell, 1896; also mapped with Pz and Pl ). Sandstone, siltstone, shale, underclay, and coal. Sandstone, feldspathic, micaceous, dark and light lithic fragments, pale-orange, light-brownish-gray, and medium to dark-gray, very-fine- to medium-grained, fine- to coarse-grained in northern outcrop area, thin- to thick-bedded and massive, sparsely cross-bedded, ripple-marked, with local shale interbeds and dark laminations; contains well-rounded quartz pebbles as much as 1 inch in diameter, locally in channel-fill deposits and basal beds; thin-bedded sandstone contains shale interbeds, shale fragments, ironstone nodules, coal debris, and sparse plant fossils. Few quartzose sandstones commonly interbedded with thin, dark-gray shales and siltstones in subsurface in Buchanan, Dickenson, and Wise counties (Miller, 1974). Sandstone comprises 70 per cent of formation (Englund,1979). Siltstone and shale, medium- to dark-gray, laminated, even- to irregulary bedded, fissile to fl ggy, fossiliferous with fresh and brackish water animal and plant fossils (Englund, 1979). Coal, finely cleated. Underclay, medium-gray, clayey to silty, contains root casts. Basal part gradational to intertonguing with underlying Bluestone Formation of the Pennington Group; base placed at top of red, green, or gray calcareous, marine shales of the underlying Bluestone Formation (Miller, 1974). The Pocahontas wedges out in the subsurface in the northwestern parts of Lee, Wise, Dickenson, and Buchanan Counties (Englund, 1979; Miller, 1974) and is thickest in western and northern Tazewell County. It ranges from 0 to 970 feet in thickness.

Wise Formation (Pennsylvanian) at surface, covers < 0.1 % 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.

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

Kanawha Formation (Campbell and Mendenhall, 1896). Sandstone, siltstone, shale, coal, and underclay. Sandstone, feldspathic, micaceous, with dark mineral grains, light- to medium-gray, fine- to coarse-grained, upper beds locally conglomeratic, lenticular, thick-bedded to massive, cross-bedded. Siltstone and shale, medium- to dark-gray, even-bedded, interbedded with sandstone, coal, and medium-gray underclay. Base of formation conformable, placed at the bottom of Kennedy coal bed overlying McClure Sandstone Member of New River Formation (Englund, 1981; Meissner and Miller, 1981; Windolph, 1987). Equivalent to the Wise Formation and upper part of the Norton Formation. Thickness: 550 + feet (J.E. Nolde, personal communications, 1993); top part eroded.