00845cam a2200253 4500 gs 68000239 DLC 20260227111422.0 690523s1968 dcuab b 00000 eng c gs 68000239 //r852 U.S. Geological Survey Library QE75 .C5 no. 562 TN271.G6 U52 Copy 2. 622/.18/41 Geological Survey (U.S.) Utilization of humus-rich forest soil (mull) in geochemical exploration for gold, by Gary C. Curtin [and others] Washington [U.S. Govt. Print. Off.] 1968. iii, 11 p. illus., maps. 26 cm. Its Circular 562 Bibliography: p. 4. Geochemical prospecting. Gold ores Colorado Empire region. Curtin, Gary C., 1935- 30467 30467