Geologic maps of the Stephenson and Winchester quadrangles, Frederick and Clarke Counties, Virginia, and Inwood and White Hall quadrangles, Berkeley and Jefferson Counties, West Virginia

First posted May 13, 2022 For additional information, contact: Florence Bascom Geoscience CenterU.S. Geological Survey926A National Center12201 Sunrise Valley DriveReston, VA 20192Contact Pubs Warehouse The study area consists of four contiguous 7.5-minute quadrangles and is located in Frederick Clarke Counties, Virginia, Berkeley Jefferson West Virginia. individual are Stephenson, Winchester, Inwood, White Hall. lies within the Great subprovince Ridge physiographic province where about 23,000 feet (ft) (7,000 meters [m]) Middle Cambrian to Upper Devonian sedimentary rocks exposed overlain by Holocene older surficial deposits. maps divided into three geologic regions based on following primary lithologies: (1) Ordovician carbonate southeast North Mountain fault zone east west core Massanutten synclinorium; (2) shale, graywacke, calcareous shale Martinsburg Formation (3) through clastic minor limestone dolostone northwest zone. Rocks all were folded faulted during late Paleozoic Alleghanian orogeny (roughly 320 250 million years before present). terrain this portion generally gently moderately rolling with low local relief elevations ranging from 425 ft (130 m) Opequon Creek flows out eastern edge Inwood quadrangle 950 (290 adjacent Round Hill western part Winchester quadrangle. Sinkholes other karst features common Valley. underlain middle strata a series ridges valleys higher relief, 785 (240 vicinity Green Spring central Hall 1,435 (437 at summit northeastern