Juniata, Oswego, Martinsburg (Reedsville and Dolly Ridge), and Eggleston Formations (VAOun;0)

State	Virginia
Name	Juniata, Oswego, Martinsburg (Reedsville and Dolly Ridge), and Eggleston Formations
Geologic age	Ordovician
Original map label	Oun
Comments	Appalachian Plateaus and Valley and Ridge. From expanded explanation (ref. VA002); Juniata, Oswego, Martinsburg (Reedsville and Dolly Ridge), and Eggleston Formations. Juniata Formation. Refer to description under Ous. Oswego Formation (Prosser, 1890). Sandstone, greenish gray, fine- to coarse-grained, conglomeratic with chert, quartz, and lithic pebbles. Minor interbeds of olive-gray shale with thin sandstone layers. Conformable with underlying Reedsville Shale. Present northeast of Bath and Augusta counties but thins in all directions from a maximum thickness of 500 feet in western Rockingham County (Diecchio, 1985). Reedsville Shale . Refer to description under Ou. Dolly Ridge Formation (Perry, 1972). Limestone, medium-gray, fine-grained, thin-bedded, argillaceous, with interbedded olive-gray, calcareous claystone, silty argillaceous limestone, gray shale and thin K-bentonite beds. Thickness about 400 feet in Bath and Highland counties; laterally equivalent to the Trenton Limestone and part of the lower Martinsburg Formation of previous reports in western Virginia. It is gradational with the underlying Eggleston Formation. Eggleston Formation. Refer to description under Ou. Martinsburg Formation. Refer to Om (Martinsburg and Oranda Formations) for description. The Martinsburg is only present with this map unit (Oun) in northern Rockingham County where it occupies the Reedsville Shale - Dolly Ridge Formation interval.
Primary rock type	shale
Secondary rock type	mudstone
Other rock types	sandstone; graywacke; limestone
Lithologic constituents	Major Sedimentary > Clastic > Sandstone Sedimentary > Clastic > Mudstone > Shale Minor Sedimentary > Clastic > Mudstone Incidental Sedimentary > Carbonate > Limestone Sedimentary > Clastic > Sandstone > Graywacke
Map references	Digital Representation of the 1993 Geologic Map of Virginia", 2003, CD ROM (ISO-9660) contains image file, expanded explanation in pdf, and ESRI shapefiles, viewing software not included. This is a digital version of "Geologic Map of Virginia" published in 1993. Available from: https://www.dmme.virginia.gov/commerce/ [https://www.dmme.virginia.gov/commerce/]
Unit references	Virginia Division of Mineral Resources, 1993, Geologic Map of Virginia: Virginia Division of Mineral Resources, scale 1:500,000 Digital Representation of the 1993 Geologic Map of Virginia - expanded explanation: 2003, Commonwealth of Virginia, Department of Mines, Minerals, and Energy, Divsion of Mineral Resources, Publication 147, 85 pp Digital Representation of the 1993 Geologic Map of Virginia", 2003, CD ROM (ISO-9660) contains image file, expanded explanation in pdf, and ESRI shapefiles, viewing software not included. This is a digital version of "Geologic Map of Virginia" published in 1993. Available from: https://www.dmme.virginia.gov/commerce/ [https://www.dmme.virginia.gov/commerce/]
Geographic coverage	Alleghany - Augusta - Bath - Botetourt - Frederick - Highland - Rockbridge - Rockingham - Shenandoah