The epicenters of the main shock and associated aftershocks of the 2011 moment magnitude, M_w 5.8 Mineral, Virginia (USA), earthquake, and the updip projection of the possible fault plane that triggered the quakes, are contained in the areas of 2 adjoining 7.5′ quadrangles in the central Virginia Piedmont. These quadrangles have therefore been the focus of concentrated geologic study in the form of bedrock and surficial mapping and near-surface trenching in order to identify potential seismogenic structures. Bedrock mapping has outlined a series of northeast-southwest–trending lithologic belts that include the Ordovician Chopawamsic and Quantico Formations, the narrow neck of...