Kirwin

Site Name

Primary: Kirwin
Secondary: Amax Kirwin
Secondary: North Side Mine
Secondary: Wolf Shaft
Secondary: Bald Mountain
Secondary: Kirwin Copper
Secondary: Kerwin

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Commodity

Primary: Copper
Secondary: Gold
Secondary: Lead
Secondary: Zinc
Secondary: Molybdenum
Secondary: Silver

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Location

State: Wyoming
County: Park
District: Kirwin

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Land Status

Land ownership: National Forest
Note: the land ownership field only identifies whether the area the mine is in is generally on public lands like Forest Service or BLM land, or if it is in an area that is generally private property. It does not definitively identify property status, nor does it indicate claim status or whether an area is open to prospecting. Always respect private property.

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Holdings

Type: Fee Ownership
Type: Located Claim
Type: Patented

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Workings

Type: Surface

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Ownership

Owner Name: Amax Inc
Percent: 100.0
Info Year: 1995
Years: 1960 - 1990

Owner Name: Shoshone National Forest
Company ID: 4800189
Percent: 100.0
Home Office: U.S. Forest Service Washington D.C.
Info Year: 1993
Years: 1993 -

Owner Name: Mellon Foundation
Percent: 100.0
Info Year: 1995
Years: 1993 - 1993

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Production

Not available

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Deposit

Record Type: Deposit
Operation Category: Past Producer
Deposit Type: Porphyry Cu
Operation Type: Surface
Mining Method: Open Pit
Milling Method: Flotation
Discovery Year: 1892
Years of Production:
Organization:
Significant: Y

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Physiography

General Physiographic Area: Rocky Mountain System
Physiographic Province: Middle Rocky Mountains

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Mineral Deposit Model

Model Name: Porphyry Cu

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Orebody

Form: PORPHYRY COPPER; HYDROTHERMAL STOCK DISSEMINATED; HYDROTHERMAL STOCK STOCKWORK; HYDROTHERMAL STOCK VEINS; SUPERGENE ENRICHMENT

Form: ARCUATE

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Structure

Type: L
Structure: N-NW trending fractures

Type: L
Structure: doming and radial fractures

Type: L
Structure: N-NW trending faults

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Alterations

Alteration Type: L
Alteration: hydrothermal

Alteration Type: L
Alteration: PROPYLITIC, SERICITIC, PHYLLIC, POTASSIC

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Rocks

Name: Andesite
Role: Associated
Description: a series of deuterically propylitized hornblende-biotite and pyroxene andesite porphyry flows, tuffs, breccias, and volcaniclastics
Age Type: Associated Rock Unit
Age Young: Tertiary

Name: Plutonic Rock
Role: Associated
Description: multi-phase-including granodiorite, monzonite porphyry, biotite dacite porphyry, and quartz litite porphyry
Age Type: Associated Rock Unit
Age Young: Tertiary

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Analytical Data

Analytical Data: MOO3 = 0.71%, MOS2 = 0.04%

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Materials

Ore: Chalcopyrite
Ore: Molybdenite
Ore: Chalcocite
Ore: Covellite
Ore: Digenite
Ore: Pyrite
Gangue: Calcite
Gangue: Chlorite
Gangue: Clay
Gangue: Barite
Gangue: Biotite
Gangue: Quartz
Gangue: Epidote

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Comments

Comment (Deposit): EXPLORATION DRILLING BY AMAX IN THE 1960'S AND 70'S DEFINED SIGNIFICANT OREBODY IN THE KIRWIN-BALD MOUNTAIN PORPYRY. PORPHYRY IS ADJACENT TO A SMALL HISTORIC MINING AREA THAT EXPLOITED PB-ZN-AG DEPOSITS IN NORTH-NORTHWEST TRENDING QUARTZ-CALCITE VEINS . THICK SUPERGENE ENRICHED CAP. TYPICAL PORPHYRY ZONING WITH PROPYLITIC ZONED OUTWARD OF PHYLLIC AND ARGILLIC ZONES. POORLY DEVELOPED POTASSIC ZONE WITH SECONDARY ORTHOCLASE ACCOMPANYING QUARTZ AND SULFIDES IN VEINLETS IN CENTRAL PART. LARGE PART OF DEPOSIT IS STOCKWORK SULFIDE VEINLETS. STOCKWORK VEINS IN THE WIGGINS FORMATION RELATED TO BURIED MIOCENE GRANODIORITE STOCK IN VENT FACIES RHYOLITIC VOLCANIC ROCKS.

Comment (Deposit): Associated Minerals: anglesite, azurite/malachite, biotite, chalcocite/digenite, chalcopyrite, chlorite, copper, covellite, cuprite, epidote, galena, goethite/limonite, gold, hematite/specularite, kaolinite/illite, magnetite, molybdenite, montmorillonite, opal, pyrite, sericite, stephanite, tetrahedrite

Comment (Deposit): Associated Rock: diorite, diorite porphyry, quartz monzonite, rhyolite tuff;granodiorite, limestone;andesite, andesite porphyry, andesite breccia, granodiorite, tuff

Comment (Reserve-Resource): COPPER PRIORITY. OTHER NAMES:AMAX KIRWIN;NORTH SIDE MINE;WOLF SHAFT. THE LAND STATUS OF THE KIRWIN PROPERTY HAS BEEN WITHDRAWN FROM MINING AFTER IT WAS DONATED TO THE U S NATIONAL FOREST BY THE MELLON FOUNDATION.

Comment (Ownership): THE SHOSHONE NATIONAL FOREST WAS GIVEN A 1,556 HA TRACT, WHICH INCLUDES THE MINING PROPERTY FORMERLY OWNED BY AMAX INC. THE LAND WAS DONATED BY THE MELLON FOUNDATION AFTER MELLON PURCHASED THE PROPERTY FROM AMAX FOR $1.9 MILLION.

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References

Reference (Deposit): Hausel, W.D., 1997, Copper, lead, zinc, molybdenum, and associated metal deposits of Wyoming; Geological Survey of Wyoming, Bulletin 70, 229 p.

Reference (Deposit): Long, K.R., 1995, Production and reserves of Cordilleran (Alaska to Chile) porphyry copper deposits, in Pierce, F.W., and Bolm, J.G., eds., Porphyry copper deposits of the American Cordillera: Tucson, Arizona Geological Society Digest 20, p. 35-68

Reference (Deposit): Hausel, D.W., 1989, The geology of Wyoming?s precious metal lode and placer deposits: Geological Survey of Wyoming Bulletin 68, 248 p.

Reference (Deposit): Hewett,D.F.,The Ore Deposits Of Kirwin,Wyo.,USGS Bulletin 540, 1912 Pp. 121-132.

Reference (Deposit): Wyo Geol Surv Open Files

Reference (Deposit): Wilson,W.H., Volcanic Geol. And Mineralization Absaroka Mountains, Northwest Wyo. In 1971 Wyo.Geol.Assoc. Guidebook

Reference (Deposit): Johnson, Md Et Al. Road Log Cody To Meeteetse And Kirwin In 27th Annual Field Conf-1975 Wyo. Geol. Assoc. Guidebook Page 287.

Reference (Deposit): Nowell, W., 1971, The petrology and alteration of the Kirwin mineralized area, Park County, WY: MS. thesis Univ. of Montana, Missoula. 72 p.

Reference (Deposit): Wilson, William H., Detachment Faulting In Volcanic Rocks Wood River Area, Park County, Wyo., Twenty-Seventh Annual Field Conference-1975, Wyo. Geol. Assoc. Guidebook, P. 167

Reference (Deposit): Wilson, William H., The Kirwin Mineralized Area, Park County Wyoming, Geological Survey Of Wyo. Preliminary Report No.2 1964

Reference (Deposit): World Mining 12/1969 (Exploration)

Reference (Deposit): Breckenridge,R.M.,Application Of Erts Imagery To Geologic Mapping In The Volcanic Terrain Of Northwest Wyo.,Dept. Of Geol. Univ. Of Wyo. 1973-Prepared For Goddard Space Flight Center.

Reference (Deposit): E/Mj 9/1972 (General)

Reference (Deposit): Hausel, D.W., 1993, Metal and gemstone deposits of Wyoming, in Snoke, A.W., Steidtmann, J.R., and Roberts, S.M., eds., Geology of Wyoming: Geological Survey of Wyoming Memoir 5, p. 816?835.

Reference (Reserve-Resource): World Mining 9/1977 P. 111 (Reserves)

Reference (Deposit): Hansen,R.P. and Glover,F., Environmental Inventory and Impact Analysis At Kirwin Area, Park County, Wyo. For Amax Submit By Rocky Mtn. Center On Environment 6/1/73 (7 Volumes)

Reference (Deposit): Schassberger, H.T., 1972, A K-Ar age of a quartz monzonite dike in the Kerwin mining district, Park County, Wyoming: Isochron/West, no. 4, p. 31.

Reference (Deposit): Osterwald and others, 1966, Mineral resources of Wyoming: WGS Bull. 50, 287 p.
Pages: p. 10, 56-57, 89.

Reference (Deposit): Hausel, D.W., 1982, General Geologic Setting and Mineralization of the Porphyry Copper Deposits, Absaroka Volcanic Plateau, Wyoming; in 33rd Annual Field Conference - 1982; Wyoming Geological Association Guidebook, pp. 297-313.
URL: http://www.wsgs.uwyo.edu/Publications/OnlinePubs/docs/R/R-40.pdf

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