A NEW GEOLOGIC MAP OF GREATER PAGE COUNTY, VIRGINIA: COMPILED AND DIGITIZED USING ARCGIS

A new 1:63,500 scale geologic map of greater Page County is being compiled from recent 1:24,000 scale geologic maps of quadrangles in the Page Valley region of northwestern Virginia. This new map updates previous geologic maps of the area, including Allen (1967) and parts of Southworth et al. (2009), Rader and Gathright (2001), King (1950), and Butts (1940). The preliminary version on display was assembled and digitized using ArcGIS 10, accompanied by field mapping in several locations to resolve discrepancies among the source maps.

Page County, Virginia encompasses an area of 316 square miles and extends from the crest of the Blue Ridge Mountains in the east to the eastern ridge of Massanutten Mountain in the west. Page County incorporates all or part of twelve 7.5 minute quadrangles: Bentonville, Big Meadows, Elkton East, Elkton West, Fletcher, Hamburg, Luray, Old Rag Mountain, Rileyville, Stanley, Tenth Legion, and Thornton Gap. The region consists of Precambrian metamorphic rocks to Devonian clastic rocks. The oldest rocks are found in the Blue Ridge province along the eastern margin of the valley, and consists of Precambrian gneisses overlain by Cambrian Chilhowee Group clastic sedimentary rocks. To the west, Ordovician carbonates in the valley floor transition to Silurian and Devonian clastic rocks that comprise the Massanutten Mountain sequence along the western edge of Page Valley.

Page Valley is bounded by prominent structural features: in the east by the western limb of the Blue Ridge anticlinorium, and in the west by the eastern limb of the Massanutten synclinorium. By primarily using detailed 1:24,000 scale maps, the updated 1:63,500 scale Page County map illustrates improved constraints on the geometry of the Blue Ridge thrust system and fold patterns associated with the Alleghanian orogeny. The valley is dominated by cryptic west directed thrust faults and upright and overturned folds that have together resulted in several kilometers of east-to-west crustal shortening. The new Page County geologic map has led to a greater understanding of lithologic patterns, deformation, and relative timing of tectonics events associated with the Alleghanian orogeny in northwestern Virginia.