Published by the American Geophysical Union as part of the Field Trip Guidebooks Series, Volume 201.
The Culpeper basin is one of a series of fault-bounded troughs of early Mesozoic age exposed discontinuously in eastern North America from South Carolina to Nova Scotia (Figure 1). These troughs formed during the continental rifting episode that led eventually to development of the Atlantic Ocean and eastern North American Atlantic Coastal Plain. The exposed Mesozoic basins are oriented subparallel to the dominant structural grain of the enclosing Precambrian and early Paleozoic metamorphic rocks of the Appalachian Piedmont and adjacent Blue Ridge provinces and some of the basins have structural characteristics which may be related to this pre-existing fabric [Lindholm, 1978; Ratcliffe and Burton, 1985]. Lithologic units within the basins are assigned to the Newark Supergroup of Late Triassic to Early Jurassic age [Froelich and Olsen, 1985] and include a thick succession of terrestrial clastic and lacustrine deposits intercalated with basalt flows.