Geologic map of the Washington West 30’ × 60’ quadrangle, Maryland, Virginia, and Washington D.C. - Lyttle, Peter; Aleinikoff, John; Burton, William; Crider Jr., E. Allen; Drake Jr., Avery; Froelich, Albert J.; Horton Jr., J.; Kasselas, Gregorios; Mixon, Robert; McCartan, Lucy; Nelson, Arthur; Newell, Wayne; et al. (Open-File Report, 2017)