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Kirwin

Past Producer in Park county in Wyoming, United States with commodities Copper, Molybdenum, Gold, Silver, Lead, Zinc
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Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Public Land Survey System information
  6. Commodities
  7. Materials information
  8. Alteration
  9. Mineral occurrence model information
  10. Host and associated rocks
  11. Nearby scientific data
  12. Geologic structures
  13. Ore body information
  14. Controls for ore emplacement
  15. Economic information about the deposit and operations
  16. Mining district
  17. Mineral rights holdings
  18. Land status
  19. Ownership information
  20. Reserves and resources
  21. Workings at the site
  22. Links to other databases
  23. Bibliographic references
  24. General comments
  25. Reporter information

Geologic information

Identification information

Deposit ID 10133042
MRDS ID W002697
MAS/MILS ID 0560290023
Record type Deposit
Mineralized Area Kirwin District
Current site name Kirwin
Alternate or previous names Amax Kirwin, North Side Mine, Wolf Shaft, Bald Mountain, Kirwin Copper, Kerwin

Geographic coordinates

Point of reference Ore Body
Geographic coordinates: -109.28465, 43.87493 (WGS84)
Elevation 3042
Location accuracy 100(meters)

Site location context

Political divisions (FIPS codes)

Park(county)

Wyoming(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Dunrud Peak(quadrangle 1:24,000 scale)

The Ramshorn(quadrangle 1:100,000 scale)

Thermopolis(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Greybull(hydrologic unit)

Big Horn(hydrologic accounting unit)

Big Horn(hydrologic subregion)

Missouri(hydrologic region)

Federal lands

Shoshone National Forest(National Forest)

National Forest FS(Type of land area)

FS(Federal land areas administered by FS)

Geographic areas

Country State County
United States Wyoming Park

Public Land Survey System information

Meridian Township Range Section Fraction State
6th Principal 045 N 104 W 11 NW Wyoming

Commodities

Commodity Importance
Copper Primary
Molybdenum Secondary
Gold Secondary
Silver Secondary
Lead Secondary
Zinc Critical Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Molybdenite Ore
Chalcocite Ore
Covellite Ore
Digenite Ore
Pyrite Ore
Calcite Gangue
Epidote Gangue
Quartz Gangue
Biotite Gangue
Chlorite Gangue
Clay Gangue
Barite Gangue

Alteration

  • (Local) hydrothermal
  • (Local) PROPYLITIC, SERICITIC, PHYLLIC, POTASSIC

Analytical data

Result MOO3 = 0.71%, MOS2 = 0.04%

Mineral occurrence model information

Model code 53
USGS model code 17
Deposit model name Porphyry Cu
Mark3 model number 4

Host and associated rocks

  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Intermediate Volcanic Rock > Andesite
    Rock type qualifier a series of deuterically propylitized hornblende-biotite and pyroxene andesite porphyry flows, tuffs, breccias, and volcaniclastics
    Rock unit name Wiggins Formation (Lower Member)
    Stratigraphic age (youngest) Tertiary
  • Host or associated Host
    Rock type Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Quartz Latite
    Rock type qualifier volcanic vent complex containing intrusive quartz latite porphyry, vent facies comglomerate and granodiorite.
    Rock unit name Bald Mountain-Kirwin formation
  • Host or associated Associated
    Rock type Plutonic Rock
    Rock type qualifier multi-phase-including granodiorite, monzonite porphyry, biotite dacite porphyry, and quartz litite porphyry
    Rock unit name Bald Mountain intrusive complex
    Stratigraphic age (youngest) Tertiary

Nearby scientific data

Ore Body (1) -109.28465, 43.87493
ListMap

Economic information

Geologic structures

Type of structure Local
Structure name N-NW trending fractures
Type of structure Local
Structure name doming and radial fractures
Type of structure Local
Structure name N-NW trending faults

Ore body information

  • General form PORPHYRY COPPER; HYDROTHERMAL STOCK DISSEMINATED; HYDROTHERMAL STOCK STOCKWORK; HYDROTHERMAL STOCK VEINS; SUPERGENE ENRICHMENT
    Thickness 96M
    Length 915M
    Width 305M
    Depth to top 38M
    Field Value
    MAS Matrix # 1
    Type of Orebody #1 FISSURE VEIN
    Shape of Orebody #1 MASSIVE
    Shape of Orebody #2 TABULAR
    Primary mode of Origin HYDROTHERMAL
    Primary Ore Control IGNEOUS
    Secondary Ore Control FRACTURING
    Degree of Wallrock Alter. MODERATE
    Type of Wallrock Alter. #1 PROPYLITIC
    Type of Wallrock Alter. #2 SERICITIC
    Type of Wallrock Alter. #3 SILICIFICATION
    Strike And Dip N40W:
    Minimum Depth to Top 15
    Avg. Thick. Unconsol. Mat. 38
    Min. Thick. Unconsol. Mat. 15
    Date of Last Modification 800821
  • General form ARCUATE
    Area 340HA
    Field Value
    Total Surface Area (HA) 340
    Date of Last Modification 910418

Controls for ore emplacement

  • volcanic vent
  • FAULTING LOCALLIZED GRANODIORITE INTRUSION

Economic information about the deposit and operations

Operation type Surface
Development status Past Producer
Commodity type Metallic
Significant Yes
Discovery year 1892
Mining method Open Pit
Milling method Flotation

Mining district

District name Kirwin

Mineral rights holdings

Type of mineral rights Patented
Type of mineral rights Located Claim
Type of mineral rights Fee Ownership

Land status

Ownership category National Forest

Ownership information

  • Type Owner
    Owner Shoshone National Forest
    ID 4800189
    Interest 100
    Home office U.S. Forest Service\nWashington D.C.
    Year 1993
    First year 1993
  • Type Owner-Operator
    Owner Mellon Foundation
    Interest 100
    Year 1995
    First year 1993
    Last year 1993
  • Type Owner-Operator
    Owner Amax Inc
    Interest 100
    Year 1995
    First year 1960
    Last year 1990

Comments on the ownership information

  • 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.

Reserves and resources

  • Type In-situ
    Estimate year 2008
    Total resources 118000000mt
    Remarks Singer and others 2008
    Commodity Subtype Grade units Group Importance Year
    Copper Cu 0.76 wt-pct Copper Primary 2008
    Silver Ag 1.5 g/mt Silver Secondary 2008
    Gold Au 0.03 g/mt Gold Secondary 2008
    Molybdenum Mo 0.02 wt-pct Molybdenum Secondary 2008
  • Type In-situ
    Estimate year 1993
    Total resources 196000000mt
    Remarks Hausel 1993
    Commodity Subtype Grade units Group Importance Year
    Copper Cu 0.505 wt-pct Copper Primary 1993
    Molybdenum Mo 0.013 wt-pct Molybdenum Secondary 1993
  • Type In-situ
    Estimate year 1977
    Measured 63520000mt ore
    Demonstrated 63520000mt ore
    Total resources 63520000mt ore
    Commodity Subtype Grade units Group Importance Year
    Copper Cu 0.75 wt-pct Copper Major 1977
    Molybdenum MoS2 0.025 wt-pct Molybdenum Minor 1977

Comments on the reserve resource information

  • 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.

Workings at the site

  • Type of workings Surface
    Area 78.9HA
    Field Value
    MAS Development Schedule # 1
    Mining Record # 1
    Status of Mining Method PROPOSED
    Mining Method OPEN PIT
    Swell Factor .67
    Percent Waste Rock 43
    Avg. Overburden Thickness 38
    Primary Material Cover M-HARD ROCKS
    Hardness of Ore HARD ROCKS
    Avg. Bench Height (meters) 14
    Max. Pit Slope (degrees) 45
    Capacity 10890
    Capacity Units MT ORE/DAY
    Preprod. Stripping Vol. 3768
    Unit Production Cost .93
    Units of Production $/MT ORE
    Operating Days per Year 356
    Operating Shifts per Day 3
    Year of Information 1977

Reference information

Bibliographic references

  • Deposit

    World Mining 12/1969 (Exploration)

  • Reserve-Resource

    World Mining 9/1977 P. 111 (Reserves)

  • 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.

  • 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.

  • 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

  • Deposit

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

  • 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.

  • 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)

  • Deposit

    Wyo Geol Surv Open Files

  • Deposit

    E/Mj 9/1972 (General)

  • Deposit

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

  • 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

  • Deposit

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

  • Deposit

    Wilson,W.H., Volcanic Geol. And Mineralization Absaroka Mountains, Northwest Wyo. In 1971 Wyo.Geol.Assoc. Guidebook

  • Deposit

    Hewett,D.F.,The Ore Deposits Of Kirwin,Wyo.,USGS Bulletin 540, 1912 Pp. 121-132.

  • Deposit

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

  • Deposit

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

  • 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.

  • Deposit

    Osterwald and others, 1966, Mineral resources of Wyoming: WGS Bull. 50, 287 p.

General comments

Subject category Comment text
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
Deposit Associated Rock: diorite, diorite porphyry, quartz monzonite, rhyolite tuff;granodiorite, limestone;andesite, andesite porphyry, andesite breccia, granodiorite, tuff
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.

Reporter information

Type Date Name Affiliation Comment
Reporter 20-SEP-96 Daley, Michael R. U.S. Bureau of Mines
Reporter 18-NOV-83 South Dakota School of Mines U.S. Bureau of Mines Also deleted record 10133418 (MAS 0560290091 and MRDS W002697)
Updater 28-APR-10 Anderson, Claire U.S. Geological Survey
Editor 11-APR-11 Wilson, Anna B. U.S. Geological Survey Merged and deleted duplicate record 10133418 (MAS 0560290091 and MRDS W002697)

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Current status (per MSHA)

StatusAbandoned since 03/08/1978
MSHA mine ID4800189
Mine name (MSHA)Kirwin Project
Current operatorC-M Inc
Mine typeSurface (Metal / non-metal)

MSHA cross-reference per the original MRDS record. Mine status and operator reflect MSHA's last published Mines export (February 2025); MSHA's public bulk feed has been unavailable since, so this may be out of date. See the Mine Data Retrieval System for current status.

Open MSHA's Mine Data Retrieval System for inspections, accidents, and violations for this mine.

Operator history (post-MRDS)

MRDS records operators as of each record's last update (≤ 2019). Some of the operators listed here have since changed hands or dissolved:

  • Amax Inc — now part of Subsidiary of Freeport-McMoRan (2007)
    Merged with Cyprus Minerals to form Cyprus Amax in 1993; Cyprus Amax → Phelps Dodge (1999) → Freeport-McMoRan (2007).

Curated by qvyshift.com from publicly-reported M&A activity (SEC filings, press releases, USGS Mineral Yearbooks). Not authoritative — verify against primary sources before relying on it. The MSHA panel above is the current authoritative source for actively-permitted mines.

External references

Maps centered on this site