Gold Basin Creek Prospect, Hot Springs Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

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

Location: The site of the Gold Basin Creek placer prospect is at a sled road crossing on the creek, in the southwest quarter of section 2, T. 3 N., R. 16 W., of the Fairbanks Meridian. The site corresponds to location 34 of Cobb (1972).
Geology: The Gold Basin prospect is one 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). A carbonatite sill(?) occurs in the Triassic strata and there are exposures of serpentinized, Cretaceous(?) mafic and ultramafic rocks, mainly on Serpentine Ridge. Gold Basin Creek flows along a northwest-trending fault in Triassic strata just north of one of the regional thrust faults. The gold- and tin(cassiterite)-bearing creeks flow normal to the trend of the tin belt. They head in the plutonic, metamorphic, and mafic/ultramafic rocks of Roughtop Mountain and Serpentine Ridge, which probably are the source(s) of some of the metalliferous minerals in the placer deposits. Concentrations of gold diminish toward the south, probably due to dispersion (Thomas, 1957). In 1917, prospectors found significant amounts of cassiterite in Gold Basin Creek, but did not find much gold. The creek was explored by drilling and prospect shafts. The gold and cassiterite were on bedrock at a depth of 40 to 80 feet (Wayland, 1961; Cobb, 1977). The exact distribution of the gold is unknown, but in the past it has proved too fine to recover. The cassiterite is similar to that in Woodchopper Creek (TN081) and is well rounded (Wayland, 1961).
Workings: In 1917, prospectors found significant amounts of cassiterite in Gold Basin Creek, but not much gold (Martin, 1919). The creek was explored by drilling and prospect shafts. The gold and cassiterite were on bedrock at a depth of 40 to 80 feet (Wayland, 1961; Cobb, 1977). The exact distribution of the gold is unknown, but in the past it has proved too fine to recover. The cassiterite is similar to that in Woodchopper Creek (TN081) and is well rounded (Wayland, 1961).
Age: Quaternary.

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

Other Databases

Link to USGS - Alaska:	TN101

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References