Minook Creek Mine, Rampart Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
Minook Creek Mine	Mine
Rampart Mining District	Mining District
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

Location: Placer gold has been mined from a two mile stretch of Minook Creek between the junctions of Ruby (TN053) and Slate (TN052) creeks. The site is at the approximate midpoint of the workings, in the southeast quarter of section 36, T. 7 N., R. 13 W., of the Fairbanks Meridian. The site corresponds to location 45 of Cobb (1972), and roughly to Minook Creek, U.S. Bureau of Land Management MAS number 0020480085.
Geology: Minook Creek is in a steeply incised, V-shaped valley, and has several gold-bearing tributaries. On the east, they include Hunter (TN062), Little Minook (TN066), Hoosier (TN059), Chapman (TN056), Little Minook Jr. (TN064), and Florida (TN058) creeks. On the west, they include Ruby (TN053) and Slate (TN052) creeks. It is possible that much of the reported mining on Minook Creek was on tributaries. Minook Creek flows along a high-angle fault, with indicated west-side uplift (Reifenstuhl and others, 1997 [RI 97-15a]). In the vicinity of the placer mining, the creek flows across Lower Paleozoic or Proterozoic calcareous siltstone, sandstone, chert, and quartzite (Chapman and others, 1982). Mining on Minook Creek started around 1902 (Collier, 1903). The gold is not in the present stream bed, but in multiple, variously developed terraces ranging from several feet to approximately 800 feet above the present channel (Eakin, 1913). The lowest bench is 25 feet above the present stream bed and has proved to be the most productive. Hess (1908) reported that most of the gold was taken from tributaries, where small sections contained as much as $3-$4 per cubic yard (gold at $20.67 per ounce). The gradient on Minook Creek is approximately 40 feet per mile in the lower stretches where gold has been reported (Waters, 1934). Native silver nuggets also occur in the placers (Hess, 1908). Around 1931, after the early period of small-scale mining, larger scale mining was considered (Mertie, 1934), but none was ever undertaken, because the distance to water for sluicing is too great. Mining has remained small-scale, and the last recorded activity was in 1967 (Smith, 1942; Saunders, 1962; Heiner and others, 1968). The only production specific to Minook Creek was $10,000 through the fall of 1904 (Hess, 1908), equivalent to approximately 485 ounces of gold (Cobb, 1977). White mica from a quartz vein one mile west of Minook Creek, and due west of McDonald Bar has an Ar40/Ar39 plateau age of 73.1 +/- 0.3 Ma (Reifenstuhl and others, 1997 [PDF 97-29h]). The sample site is downstream from the Minook Creek placer, but similar quartz veins upstream may be the source of some of the placer gold.
Workings: Minook Creek was mined by surface workings, including hydraulicking (Mertie, 1934). The mining appears to have been spotty, predominantly in the lowest, best-formed benches. Hess (1908) stated that most of the production was from tributaries of Minook Creek, and that gold from Minook Creek came from the central portion of the valley, partly by bar diggings and partly by drifting. Around 1931, after the early period of small-scale mining, larger scale mining was considered (Mertie, 1934), but none was ever undertaken, because the distance to water for sluicing is too great. Mining has remained small-scale, and the last recorded activity was in 1967 (Smith, 1942; Saunders, 1962; Heiner and others, 1968).
Age: Quaternary.
Production: By 1904, Minook Creek had produced approximately $10,000 in gold (Hess, 1908), equivalent to approximately 485 ounces of gold (Cobb, 1977).

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

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Link to USGS - Alaska:	TN054

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References