00621nam a22001931 4500 gs 50000193 DLC 20260227111356.0 900309m19501952enkabf b 100 0 eng c gs 50000193 U.S. Geol. Survey Libr./ICU ICU QE1 .I6 1948c International Geological Congress (18th : 1948 : London, England) Report of the eighteenth session, Great Britain, 1948. London, 1950-<52 > v. <1-13, 15 > illus., plates, maps. 25 cm. Includes "References." Geology Congresses. 28484 28484