00985cam a22002651 4500 gs 40000142 DLC 20260227111345.0 780829s1939 paud b s000 0 eng c gs 40000142 (OCoLC)4175406 U.S. Geol. Survey. Library PU DLC premarc TN24.P4 A7 TN403.P4 H5 Copy 2. Hickok, William Orville, 1905- The minerals of Pennsylvania: Iron ores of Pennsylvania, by William O. Hickok, IV. Harrisburg, Pa., Department of Internal Affairs, Topographic and Geologic Survey, 1939. 21 p. incl. tables. 23 cm. Bulletin M, 18-B At head of title: Pennsylvania Geological survey, Fourth series With Ashley, G. H. The undeveloped mineral resources of Pennsylvania. 1933. (Bulletin M18-A) Bibliographical footnotes. Iron ores Pennsylvania. 27625 27625