This publication is part of a folio of maps of the Springfield 10° × 20° quadrangle, Missouri, prepared under the Conterminous United States Minera1 Assessment Program of the U.S. Geological Survey. Other publications in this folio to date include U.S. Geological Survey Miscellaneous Field Studies Maps MF-1830-A through E (Erickson and others, 1985; Whitfield, 1986; Wharton, 1987; Middendorf and others, 1987; Kisvarsanyi, 1987) and Missouri Geological Survey Open-file Report OFR85-42-MR (Martin and Pratt, 1985).