Big Denver Creek Prospect, Hot Springs Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
Big Denver Creek Prospect	Prospect
Hot Springs Mining District	Mining District
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

Location: Thirty mining claims were staked along Big Denver Creek in the early 1980s (Alaska Kardex files). The claims extended from the headwaters of Big Denver Creek near the summit of Manley Hot Springs Dome, for 4 miles downstream along the main channel of Big Denver Creek, and along two of its branches. For this record, the site is at North Rain claim number 14, where work was performed in 1983. The claim is in the southwest quarter of the southeast quarter of section 8, T. 2 N., R. 16 W., of the Fairbanks Meridian; other claims extend above and below this site. The location is accurate within about 500 feet. This site closely corresponds with the site for Big Denver, U.S. Bureau of Land Management MAS number 0020480054.
Geology: The Big Denver Creek prospect is south of a group of cassiterite- and gold-bearing placer deposits known as the Tofty tin belt, a 12-mile-long area that trends east-northeast, between Roughtop Mountain to the north and Hot Springs Dome to the south (Thomas, 1957). Roughtop Mountain and Hot Springs Dome respectively are underlain by Cretaceous (K-Ar age date of 92 +/- 5 Ma) and Tertiary (K-Ar age date of 62 +/- 3 Ma) granitic plutons (Chapman and others, 1982). The plutons intrude and contact metamorphose Mesozoic marine sedimentary strata, which also are cut by diverse faults, including regional-scale, east-northeast-striking, thrust faults (Reifenstuhl and others, 1998). Bedrock at the Big Denver Creek prospect is mainly Cretaceous sandstone, shale, and siltstone (Reifenstuhl and others, 1998). The upper end of the claim block is in the hornfels aureole of the Tertiary Hot Springs Dome granite pluton. The hornfels is black, dense rock containing unoriented crystals or rosettes of muscovite, biotite, and andalusite. Placer mining claims were staked along Big Denver Creek in 1981 and the claims were worked from 1981 to 1986 (Alaska Kardex files). An affidavit of annual labor in 1983 lists 30 state mining claims and sample holes dug to bedrock or permafrost on North Rain claims 10-13. The material was sampled and analyzed. A trench dug to bedrock across the old dry bed of Big Denver Creek on North Rain claim 14 was also sampled. The sample analyses are not available.
Workings: Placer mining claims were staked along Big Denver Creek in 1981 and the claims were worked from 1981 to 1986 (Alaska Kardex files). An affidavit of annual labor in 1983 lists 30 state mining claims and sample holes dug to bedrock or permafrost on North Rain claims 10-13. The material was sampled and analyzed. A trench dug to bedrock across the old dry bed of Big Denver Creek on North Rain claim 14 was also sampled. The sample analyses are not available.
Age: Quaternary?

Commodities (Major) - Au
Development Status: Undetermined.
Deposit Model: Placer Au (Cox and Singer, 1986; model 39a).

Other Databases

Link to USGS - Alaska:	TN095

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References