Kemuk Prospect, Bristol Bay Region Mining District, Dillingham Census Area, Alaska, USAi

Regional Level Types
Kemuk Prospect	Prospect
Bristol Bay Region Mining District	Mining District
Dillingham Census Area	Census Area
Alaska	State
USA	Country

Location: The Kemuk prospect is in the north-central Dillingham C-5 quadrangle 12 miles east-northeast of the summit of Kemuk Mountain. The map site is at the south end of the boundary between sections 19 and 20, T 5 S, R 49 W, of the Seward Meridian. This is an area of extensive surficial deposits with few conspicuous topographic features. Napotoli Creek is 1.9 miles directly north and Klutuk Creek is 8 miles directly south of the prospect. The location is accurate to within 1 mile.
Geology: The Kemuk prospect was first discovered as a result of an aeromagnetic survey flown for Humble Oil and Refining Company in 1959 (Berg and Cobb, 1967, p. 11). The map site is at the approximate center of a 4 square mile aeromagnetic anomaly. Buried below 90 to 140 feet of unconsolidated Quaternary deposits is a large, composite ultramafic and mafic pluton. The pluton is known from the results of 16 diamond drill holes, some drilled to almost 2,000 feet. It is a composite, tabular, southeast-dipping body (Nokleberg and others, 1987) of abundant clinopyroxenite, some olivine-bearing rocks, and some hornblende-bearing rocks (T. Hinderman, personal commun., 2000). Country rocks encountered in some drill holes are hornfels and quartzite. The metalliferous mineral is titaniferous magnetite that probably occurs as segregations and disseminations in clinopyroxenite. This prospect is believed to contain 2.4 billion long tons averaging 15 to 17 percent total Fe (Nokleberg and others, 1987). The average grade is 10.5 to 12 percent magnetic Fe and 15 to 17 percent total Fe. A beneficiation test indicates the feasibility of producing a concentrate containing 65 percent Fe, 2 to 3 percent SiO2, 0.005 to 0.016 percent P2O5, and 2 to 3 percent TiO2. The platinum-group metal (PGM) potential of this prospect is now being evaluated (T. Hinderman, personal commun., 2000).
Workings: The Kemuk prospect was first discovered as a result of an aeromagnetic survey flown for Humble Oil and Refining Company in 1959 (Berg and Cobb, 1967, p. 11). It was subsequently explored by this company with 16 diamond core drill holes to maximum depth of about 2,000 feet.
Age: Not known; the age of the country rocks is uncertain. From regional trends, they could be clastic sedimentary rocks of either Jurassic or Cretaceous age (Decker and others, 1994). The quartz-rich character of the country rocks suggests that they could be older than Cretaceous (Mertie, 1938). The composite ultramafic pluton at Red Mountain in the Hagemeister Island quadrangle to the west is Jurassic in age.
Reserves: This prospect is believed to contain 2.4 billion long tons averaging 15 to 17 percent total Fe (Nokleberg and others, 1987). The average grade is 10.5 to 12 percent magnetic Fe and 15 to 17 percent total Fe. A beneficiation test indicates the feasibility of producing a concentrate containing 65 percent Fe, 2 to 3 percent SiO2, 0.005 to 0.016 percent P2O5, and 2 to 3 percent TiO2.

Commodities (Major) - Fe; (Minor) - Ti, PGM (?)
Development Status: None
Deposit Model: Titaniferous magnetite in clinopyroxenite; Alaska PGE ? (Cox and Singer, 1986;

Other Databases

Link to USGS - Alaska:	DI003

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References