Juniata, Reedsville, Trenton, and Eggleston Formations

Juniata Formation (Darton and Taff, 1896). Siltstone, shale, sandstone, and limestone. Siltstone, shale, and sandstone, locally calcareous, grayish-red, locally fossiliferous; with some interbeds of greenish-gray shale, quartzarenite, and argillaceous limestone. Cycles consisting of a basal, crossbedded quartzarenite with a channeled lower contact; a middle unit of interbedded mudstone and burrowed sandstone; and an upper bioturbated mudstone are commonly present north of New River (Diecchio, 1985). The Juniata Formation ranges from less than 200 to more than 800 feet in thickness. In southwestern Virginia the red, unfossiliferous, and argillaceous Juniata Formation is present in the southeastern belts. It is equivalent to the gray, fossiliferous, and limy Sequatchie Formation of western belts (Thompson, 1970; Dennison and Boucot, 1974). Even though the beds along Clinch Mountain, in Scott County, contain minor amounts of carbonate rock (Harris and Miller, 1958) the majority is grayish- red siltstone, which is typical of the Juniata Formation. Reedsville Shale. Refer to description under Ou. Trenton Limestone. Refer to description under Ou. Eggleston Formation. Refer to description under Ou.
State Virginia
Name Juniata, Reedsville, Trenton, and Eggleston Formations
Geologic age Ordovician
Lithologic constituents
Major
Sedimentary > Clastic > Mudstone > Shale
Minor
Sedimentary > Clastic > Sandstone
Sedimentary > Clastic > Mudstone
Incidental
Sedimentary > Carbonate > Limestone
Comments Thrustbelt in Southwestern Virginia; Appalachian Plateaus and Valley and Ridge
References

Virginia Division of Mineral Resources, 1993, Geologic Map of Virginia: Virginia Division of Mineral Resources, scale 1:500,000.

Virginia Division of Mineral Resources, 2003, Digital Representation of the 1993 Geologic Map of Virginia, Publication 174, CD ROM (ISO-9660) contains image file, expanded explanation in pdf, and ESRI shapefiles, scale 1:500,000.

NGMDB product
Counties Alleghany - Bland - Botetourt - Craig - Giles - Montgomery - Pulaski - Roanoke - Russell - Scott - Smyth - Tazewell - Washington - Wythe - Radford - Roanoke - Salem