00820cam a22002411 4500 gs 19000035 DLC 20260227111323.0 760209s1918 dcuabf f000 0 eng gs 19000035 (OCoLC)1979188 DLC IDeKN OCoLC DLC premarc QE75 .B9 no. 681 TN483.C6 L8 Copy 2. Loughlin, G. F. (Gerald Francis), 1880-1946. The oxidized zinc ores of Leadville, Colorado, by G. F. Loughlin. Washington, Govt. print. off., 1918. 91 p. VIII pl. (part fold.; incl. map, diagrs.) diagrs. 24 cm. U.S. Geological survey. Bulletin 681 At head of title: Department of the interior. Zinc mines and mining Colorado. 25900 25900