01283cam a2200337 4500 gs 68000264 DLC 20260227111422.0 690523s1968 dcuab 00010 eng c gs 68000264 //r935 U.S. Geological Survey Library DLC DLC n-us-co QE75 .C5 no. 567 QE389.5 .S5 Copy 2. 549.5/24 Sheridan, Douglas M., 1921- Rutile and topaz in Precambrian gneiss, Jefferson and Clear Creek Counties, Colorado, by Douglas M. Sheridan, Richard B. Taylor, and Sherman P. Marsh. Washington, 1968. iii, 7 p. illus., map. 26 cm. Geological Survey circular 567 Rutile Colorado Jefferson County. Rutile Colorado Clear Creek County. Topaz Colorado Jefferson County. Topaz Colorado Clear Creek County. Gneiss Colorado Jefferson County. Gneiss Colorado Clear Creek County. Geology, Stratigraphic Precambrian. Taylor, Richard B. (Richard Bartlett), joint author. Marsh, Sherman P., 1935- joint author. Geological Survey circular ; 567. 30486 30486