1. Low-flow characteristics and chemical quality of streams in the Culpeper geologic basin, Virginia and Maryland [cartographic material] Yale Public content 1987. 2002-06-01T04:00:00Z. 2015-07-14T22:20:38Z. Geological Survey (U.S.). The Survey ; For sale by Branch of Distribution. English. cartographic image. Public. Culpeper Basin (Va. and Md.).