Theobald, P.K., and Barton, H.N., 1988, Maps showing anomalous concentrations of zinc, silver, antimony, manganese, barium, and strontium in stream sediment and heavy-mineral concentrate from parts of the Ajo and Lukeville 1o x 2o quadrangles, Arizona: U.S. Geological Survey Miscellaneous Field Studies Map MF-1834-E, 1 sheet, scale 1:500,000.
