Tolstoi Creek Prospect (ARDF - ID007), Innoko Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
Tolstoi Creek Prospect (ARDF - ID007)	Prospect
Innoko Mining District	Mining District
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

Location: This prospect at an elevation of about 1,400 feet on an unnamed tributary of Tolstoi Creek. It is about 1.0 mile north of hill 2008 and about 0.4 mile southwest of the northeast corner of section 2, T. 33 N., R. 41 W., of the Seward Meridian. The location is accurate.
Geology: The Tolstoi Creek prospect is a black-sand-rich gold placer that contains visible gold, abundant magnetite, ilmenite, less abundant ilmenorutile, a Nb-Ta mineral, cinnabar, tourmaline (variety dravite), and a trace of chalcopyrite (Bundtzen, Cox and Veach, 1987). The creek is about 30 feet wide and is incised in glacial moraine of late Pleistocene age. The alluvium is poorly sorted; most of the gold and heavy minerals occur in sand and gravel that is interstitial to erratic boulders that originated in the Beaver Mountains (Bundtzen and Laird, 1980). The placer gold is mostly fine-grained with occasional grains to 5 mm across. Six pans collected at intervals across the creek contained from 1 to 5 grains of gold per pan (Bundtzen, Cox and Veach, 1987). The average fineness of the placer gold as determined by fire assay is 891. One placer concentrate contained 214 parts per million (ppm) niobium 14 ppm tantalum, 8.1 ppm gold, and 1.0 ppm silver (Bundtzen, Cox, and Veach, 1987).
Workings: Placer occurrences in this area were prospected during the early part of the 20th century (Mertie, 1936). The placer was sampled by the Alaska Division of Geological and Geophysical Surveys in the 1980s (Bundtzen, Cox, and Veach, 1987).
Age: The prospect is in reworked, glacial moraine of Late Pleistocene (Wisconsin?) age and the placer is either late Pleistocene or Holocene in age (Bundtzen, 1980 [GR 63]).
Alteration: None.
Production: No known production.

Commodities (Major) - Au; (Minor) - Cu, Hg, Nb, Ta
Development Status: None
Deposit Model: Placer Au deposit (Cox and Singer, 1986; model 39a).

Other Databases

Link to USGS - Alaska:	ID007

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References