Waynesboro Formation and Tomstown Dolomite

Waynesboro Formation (Stose, 1906). Largely dolostone and limestone with distinctive upper and lower sequences of interbedded red mudrock, red sandstone, and dolostone. Dolostone, light- and dark-gray, mottled, fine- to coarse-grained, thick-bedded, calcareous. Limestone, medium-gray, fine-grained, thick-bedded, locally with black chert nodules. Mudrock, grayish-red, locally fissile, interbedded with dolostone and sandstone. Sandstone, dark- grayish red, fine- to medium-grained, medium- to thin-bedded, forms low ridges and hills. The Waynesboro Formation is laterally equivalent to the Rome Formation and is only present northeast of Roanoke. It is well exposed in Botetourt County (Haynes, 1991) and in Clarke County (Gathright and Nystrom, 1974) where lower shale beds of the Elbrook Formation were incorrectly included in the Waynesboro as an upper member. It is conformable with the underlying Tomstown Dolomite and is between 1100 and 1200 feet thick. Tomstown Dolomite (Stose, 1906). Dolostone, limestone and minor chert. Dolostone (upper member), light- to dark gray, fine- to coarse-grained, medium- to thick-bedded, locally laminated with white chert nodules in uppermost beds; about 600 feet thick. Dolostone (high magnesian member), very-light-gray to yellowish-white, medium- to coarse-grained, very-thick-bedded, locally dark-gray, fine-grained and with white, coarse-grained, lenticular dolostone mottling; about 200 feet thick. Limestone, very-dark-gray, very-fine-grained, thin-bedded, partly dolomitic, with shaly partings; about 325 feet thick. The Tomstown is lithologically similar to, but thinner than the Shady Dolomite of southwestern Virginia and conformably overlies the Antietam Formation.
State Virginia
Name Waynesboro Formation and Tomstown Dolomite
Geologic age Cambrian
Lithologic constituents
Sedimentary > Carbonate > Dolostone
Sedimentary > Clastic > Mudstone > Shale
Sedimentary > Carbonate > Limestone
Sedimentary > Clastic > Sandstone
Sedimentary > Chemical > Chert
Comments Appalachian Plateaus and Valley and Ridge

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 Clarke - Page - Warren