Upper Mississippi Valley Base-Metal District Companion volume to Information Circular 16 (third edition). Prepared for 24th Annual Meeting, Institute on Lake Superior Geology. Bedrock Geology Driftless Area Metallic Minerals Rocks and Minerals Data and Resources FTGB01 Upper Mississippi Valley Base-Metal District Broughton, W.A.; Heyl, A.V.; Mudrey, M.G., Jr.; Ostrom, M.E.; Paull, R.K.; Paull, R.A.; West, W.S.; 1978 Report: 39 p. Download Related Collections Field Trip Guide Book View Field Trip Guide Book
