Mineral investigations in the Valdez Creek Mining District, South- central Alaska.
Kurtak-JM; Southworth-DD; Balen-MD; Clautice-KH
Anchorage, AK: U.S. Department of the Interior, Bureau of Mines, OFR 1-92, 1991 Jan; :1-658
The U.S. Bureau of Mines conducted a 4-year (1987-90) mineral resource assessment of the Valdez Creek Mining District, south- central Alaska. A total of 237 mineral occurrences in the 5.7- million-acre district were examined. This includes 19 previously unreported occurrences, considered to be significant. Placer gold has been the main commodity produced for the district. Deposits consist mainly of buried interglacial paleochannels and reworked Tertiary conglomerate. Placer production from 1903 to 1989 totals 257,340 oz gold, and measured placer resources total an estimated 182,226 oz gold. There is, in addition, an undetermined amount of platinum-group metals in the placers. Lode production from breccia pipes and quartz veins totals 1,580 oz gold. Breccia pipe and skarn deposits contain an indicated resource of 446,000 oz gold. Subbituminous coal production resulted as a byproduct of precious metal mining. Sediment-hosted volcanogenic sulfide deposits and skarn deposits contain an indicated resource of 226 million lb of copper. Sheeted greisen veins contain an indicated resource totaling 5.0 million tons averaging 0.2 pct tin. Bureau studies indicate potential for placer gold, vein stockwork, and sediment- hosted lode gold and silver deposits. Serpentinized dunite and gabbro contain anomalous amounts of platinum-group metals, nickel, and chromium. Samples collected near several diorite porphyry stocks are anomalous in tin.
Prospecting; Sampling; Exploitation; Placers; Metalliferous-mineral-deposits; Precious-metal-ore-deposits; Molybdenum-ore-deposits; Copper-ore-deposits; Tin-ore-deposits; Zinc-ore-deposits; Geology; Resource-potential; Resource-development; Mineral-economics; Feasibility-studies; Mineral-resources; Resource-assessment; Mineral-exploration
Anchorage, AK: U.S. Department of the Interior, Bureau of Mines, OFR 1-92