Foggy Day

Site Name

Primary: Foggy Day
Secondary: Read
Secondary: Paigite
Secondary: Cameron

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Commodity

Secondary: Uranium
Secondary: Lead
Secondary: Silver

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Location

State: Alaska
District: Port Clarence

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Land Status

Not available

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Holdings

Not available

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Workings

Not available

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Ownership

Not available

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Production

Not available

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Deposit

Record Type: Site
Operation Category: Prospect
Operation Type: Unknown
Years of Production:
Organization:
Significant:

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Physiography

Not available

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Mineral Deposit Model

Model Name: Sn skarn

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Orebody

Not available

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Structure

Not available

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Alterations

Alteration Type: L
Alteration Text: Primarily calc-silicate tactite development but with significant associated boron metasomatism.

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Rocks

Role: Associated
Age Type: Associated Rock
Age in Years: 77.000000+-3.000000
Age Young: Late Cretaceous

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Analytical Data

Not available

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Materials

Ore: Zeunerite
Ore: Galena

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Comments

Comment (Geology): Age = Chronological age is for Brooks Mountain.

Comment (Geology): Age = the age of the mineralization is assumed to be similar to the age of the Brooks Mountain granite (77.0 +/- 3.0 my; Hudson and Arth, 1983, p. 769).

Comment (Deposit): Model Name = This is an approximate 1,500 by 3,000 foot area of variable contact metamorphism of Ordovician limestone near the contract of the Brooks Mountain granite stock. Possibly tin skarn (Cox and Singer, 1986, model 14b).

Comment (Geology): Geologic Description = Brooks Mountain granite stock is a 1 by 2 mile composite intrusion just south and east of Brooks Mountain (elevation 2,898 feet), the highest part of the York Mountains. The country rocks to the Late Cretaceous (77.0 +/- 3.0 my; Hudson and Arth, 1983, p. 769) Brooks Mountain granite are Ordovician limestone and locally fine-grained, carbonaceous metaclastic rock of unknown but probable Paleozoic age. Tactite is common in marble nearby to the granite contact on the northwest and southwest sides of the stock (Sainsbury, 1969, plate 1). Hornfels is developed in the nearby metaclastic rocks. The granite is dominately seriate and prophyritic types (Hudson and Arth, 1983, p. 770) that are not known to be directly linked with significant tin metallization in the western Seward Peninsula tin belt; they are instead precusor-type granites (Hudson and Reed, 1997, figure 3). The mineralization in this area is associated with contact metamorphic rocks developed in Ordovician limestone peripheral to the southwest contact of the Brooks Mountain granite stock. Complex mineralogy characterizes the occurrences here. Tactite forms seams and irregular masses in crystalline marble; idocrase, garnet, diopside, augite, hedenbergite, phlogopite, and fluorite are present in the tactite. Sulfide minerals, dominately galena, include pyrrhotite, stannite, sphalerite, pyrite, arsenopyrite, chalcopyrite, chalcocite, and bornite. Other minerals include scapolite, chrondrodite, siderophyllite, tourmaline, scheelite, ludwigite, magnetite, hematite, limonite, cerussite, azurite, malachite, paigite, and hulsite. Zuenerite is locally present in association with hematite in oxidized granite adjacent to marble. This is primarily an area of interesting mineral occurrences although selected samples of galena-rich material assayed 34% lead and 11 opt silver (Knopf, 1908, p. 42-43) and zuenerite-rich material contained up to 2.14% eU (West and White, 1952, p. 4).

Comment (Exploration): Status = Inactive

Comment (Reference): Primary Reference = Knopf, 1908 (USGS B 358); West and White, 1952

Comment (Reserve-Resource): Reserves = Not defined

Comment (Workings): Workings / Exploration = Several surface pits and some dozer trenches have been completed here.

Comment (Commodity): Gangue = Complex mineralogy characterizes assemblages

Comment (Geology): Ore Material = but complex mineralogy characterizes this area

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References

Reference (Deposit): Sainsbury, C.L., 1969, Geology and ore deposits of the central York Mountains, western Seward Peninsula, Alaska: U.S. Geological Survey Bulletin 1287, 101 p.

Reference (Deposit): Cobb, E.H., 1975, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Teller quadrangle, Alaska: U.S. Geological Survey Open-File Report 75-587, 130 p.

Reference (Deposit): Hudson, T.L., and Reed, B.L., 1997, Tin deposits of Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska: Economic Geology Monograph 9, p. 450-465.

Reference (Deposit): West, W.S., and White, M.G., 1952, The occurrence of zeunerite at Brooks Mountain, Seward Peninsula, Alaska: U.S. Geological Survey Circular 214, 7 p.

Reference (Deposit): Cobb, E.H., 1975, Tungsten occurrences in Alaska: U.S. Geological Survey Mineral Investigations Resource Map MR-66, 1 sheet, scale 1:250,000.

Reference (Deposit): Patton, T.L., and Robinson, M.S., 1975, Bedrock geology, geochemistry, and geophysics of Brooks Mountain, Seward Peninsula, Alaska: University of Alaska, Fairbanks, M.Sc. thesis, 106 p.

Reference (Deposit): Knopf, Adolph, 1908, Geology of the Seward Peninsula tin deposits, Alaska: U.S. Geological Survey Bulletin 358, 71 p.

Reference (Deposit): Cobb, E.H., and Sainsbury, C.L., 1972, Metallic mineral resource map of the Teller quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-426, 1 sheet, scale 1:250,000.

Reference (Deposit): Hudson, T.L., and Arth, J. G., 1983, Tin-granites of Seward Peninsula, Alaska: Geological Society of America Bulletin, v. 94, p. 768-790.

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