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Heddleston Deposit

Past Producer in Lewis and Clark county in Montana, United States with commodities Copper, Molybdenum, Silver, Gold, 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 10221947
MRDS ID W016825
MAS/MILS ID 0300490004
Record type Deposit
Current site name Heddleston Deposit
Alternate or previous names Heddleston Copper Project, Heddleston Group, Carbonate Mine - 0300490040, Midnight Mine - 0300490284, Paymaster Mine - 0300490242, Anaconda Mine - 0300490146, Mike Horse Mine - 0300490362

Comments on the site names

  • MIKE HORSE, ANACONDA, MIDNIGHT, CARBONATE AND PAYMASTER ARE NAMES OF PATENTED CLAIMS, VEINS AND MINES.

Geographic coordinates

Point of reference Ore Body
Geographic coordinates: -112.3627, 47.0233 (WGS84)
Elevation 1682
Location accuracy 100(meters)

Site location context

Political divisions (FIPS codes)

Lewis and Clark(county)

Montana(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Rogers Pass(quadrangle 1:24,000 scale)

Dearborn River(quadrangle 1:100,000 scale)

Choteau(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Blackfoot(hydrologic unit)

Pend Oreille(hydrologic accounting unit)

Kootenai-Pend Oreille-Spokane(hydrologic subregion)

Pacific Northwest(hydrologic region)

Federal lands

Helena-Lewis and Clark 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 Montana Lewis and Clark

Public Land Survey System information

Meridian Township Range Section Fraction State
Montana Principal 015 N 006 W 16. 19, 20, 21, 27, 28 Montana

Commodities

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

Materials information

Materials Type of material
Chalcocite Ore
Chalcopyrite Ore
Covellite Ore
Molybdenite Ore
Pyrite Ore
Sphalerite Ore
Galena Ore
Arsenopyrite Ore
Bornite Ore
Tetrahedrite Ore
Biotite Gangue
Feldspar Gangue
Plagioclase Gangue
Quartz Gangue

Alteration

  • (Local) SUPERGENE
  • (Local) Seriticization

Mineral occurrence model information

Model code 79
USGS model code 21a
Deposit model name Porphyry Cu-Mo
Mark3 model number 2
Model code 80
USGS model code 21b
Deposit model name Porphyry Mo, low-F

Host and associated rocks

  • Host or associated Host
    Rock type Plutonic Rock > Granitoid > Quartz Monzonite
    Rock type qualifier QUARTZ MONZONITE PORPHYRY
  • Host or associated Host
    Rock type Plutonic Rock > Porphyry
    Rock type qualifier QUARTZ PORPHYRY
  • Host or associated Associated
    Rock type Metamorphic Rock > Metasedimentary Rock > Quartzite
    Rock type qualifier QUARTZITES
    Rock unit name BELT SERIES SPOKANE FORMATION
  • Host or associated Associated
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Argillite
    Rock type qualifier ARGILLITES
    Rock unit name BELT SERIES SPOKANE FORMATION
  • Host or associated Associated
    Rock type Plutonic Rock > Mafic Intrusive Rock > Diorite
    Rock type qualifier DIORITE
    Stratigraphic age (youngest) Eocene
  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Trachyte

Nearby scientific data

Ore Body (1) -112.3627, 47.0233
ListMap

Economic information

Geologic structures

Type of structure Regional
Structure name LEWIS AND CLARK LINEAMENT
Type of structure Regional
Structure name LEWIS THRUST FAULT
Type of structure Local
Structure name TWO NW-TRENDING FAULTS:MIKE HORSE FAULT&BLACKFOOT FAULT

Ore body information

  • Strike N20W
    Dip 89E
    Thickness 273M
    Length 2253M
    Width 46M
    Area 1416HA
    Depth to top 38M
    Field Value
    Type of Orebody #1 DISSEMINATED
    Shape of Orebody #1 MASSIVE
    Type of Orebody #2 STOCKWORK
    Type of Orebody #3 BRECCIA FILL
    Primary mode of Origin HYDROTHERMAL
    Secondary mode of Origin OXIDATION
    Primary Ore Control IGNEOUS
    Secondary Ore Control CONTACT ZONE
    Degree of Wallrock Alter. INTENSE
    Type of Wallrock Alter. #1 POTASSIC
    Type of Wallrock Alter. #2 SILICIFICATION
    Type of Wallrock Alter. #3 SERICITIC
    Strike And Dip N20W:89E
    Minimum Depth to Top 23
    Avg. Thick. Unconsol. Mat. 2
    Min. Thick. Unconsol. Mat. 0
    Total Surface Area (HA) 1416
    Date of Last Modification 830316
  • General form lenses and shoots
    Strike N 70 W
    Dip 75 S

Controls for ore emplacement

  • Faulting
  • Replacement

Economic information about the deposit and operations

Operation type Surface
Development status Past Producer
Commodity type Metallic
Significant Yes
Discovery year 1898
Discoverer Joseph Heitmiller
Mining method Open Stope - Gophering (Coyoting)
Year of first production 1915
Milling method Flotation

Mining district

District name Heddleston District
District name Blackfoot District
District name Silver District

Mineral rights holdings

Type of mineral rights Patented
Type of mineral rights Located Claim
Type of mineral rights Private Lease

Land status

Ownership category National Forest
Ownership category Private

Ownership information

  • Type Owner
    Owner Asarco (American Smelting And Refining Co.)
    ID 2401105
    Interest 100
    Home office Washington
    Year 1984

Comments on the production information

  • PRODUCTION AND DEVELOPMENT reported from 1940 TO 1952 at Mike Horse mine.
  • TOTAL EST. PROD. OF DISTRICT $120,000, HALF WAS PB REST AU, AG, CU

Reserves and resources

  • Type In-situ
    Estimate year 2009
    Total resources 113000000mt ore
    Remarks Converted to approximate weight from reported 125,000,000 tons
    Commodity Subtype Grade units Group Importance Year
    Molybdenum Mo 0.015 wt-pct Molybdenum Secondary 2009
    Silver Ag 4.2 g/mt Silver Secondary 2009
    Copper Cu 0.49 wt-pct Copper Primary 2009
  • Type In-situ
    Estimate year 1981
    Total resources 148152960mt ore
    Commodity Subtype Grade units Group Importance Year
    Molybdenum Mo 0.16 wt-pct Molybdenum Secondary 1981
    Copper Cu 0.1 wt-pct Copper Primary 1981
  • Type In-situ
    Estimate year 1978
    Demonstrated 84368000mt ore
    Total resources 84368000mt ore
    Commodity Subtype Grade units Group Importance Year
    Silver Ag 5.14 g/mt Silver Minor 1978
    Copper Cu 0.48 wt-pct Copper Major 1978
    Molybdenum Mo 0.01 wt-pct Molybdenum Minor 1978
  • Type In-situ
    Estimate year 1967
    Commodity Subtype Grade units Group Importance Year
    Molybdenum 0.013 wt-pct Molybdenum Minor 1967
    Copper 0.363 wt-pct Copper Major 1967

Comments on the reserve resource information

  • COPPER PRIORITY. ONE DRILL HOLE - NO OTHER DATA.
  • Current drill-indicated resource estimate of 125 million tons of ore at .49% Cu, .015% Mo and .15 opt Ag. (Potential to add at least another 50 million tons of ore to resource at peripheral areas is reported in sale papers.)

Workings at the site

  • Type of workings Surface
    Field Value
    MAS Development Schedule # 1
    Mining Record # 1
    Status of Mining Method PROPOSED
    Mining Method BENCH (BERM)
    Swell Factor .35
    Percent Waste Rock 71.4
    Avg. Overburden Thickness 38
    Primary Material Cover SAND, GRAVEL
    Percentage 2
    Secondary Material Cover HARD ROCKS
    Percentage 36
    Hardness of Ore HARD ROCKS
    Capacity 12000
    Capacity Units MT ORE/DAY
    Preprod. Stripping Vol. 1907
    Unit Production Cost 1.97
    Units of Production $/MT ORE
    Operating Days per Year 350
    Operating Shifts per Day 3
    Year of Information 1977
  • Type of workings Underground
    Length 426.72M
    Overall depth 137.16M

Comments on the workings information

  • WORKINGS IN 1933 INCLUDED 3 ADITS, TUNNELS 1, 2, AND 3, SPACED THROUGH A VERTICAL RANGE OF ABOUT 300 FT.
  • Anaconda completed extensive RC, core and churn drilling of the project in the 1960?s and Asarco continued a drilling program into the 1990?s. (358 holes with over 250,000 feet of churn, RC and diamond drilling)

Comments on other economic factors

  • APPROXIMATELY $25,000,000 PRODUCED FROM 1889 TO 1958 OF LEAD, ZINC, COPPER, SILVER, AND GOLD (MILLER AND OTHERS, 1973).

    ?THE U.S BUREAU OF MINES HAS CREDITED THIS DISTRICT WITH A PRODUCTION OF ABOUT $11.6 MILLION, WITH THE BULK OF THE VALUE COMING FROM THE MIKE HORSE MINE.? (MCCLERNAN, 1983)

    RESERVES (EYDE, 1972):

    DEVELOPED- 20 MILLION TONS @0.53 CU, 0.01 TO 0.015% MO AND 0.15 OPT AG

    PROBABLE- 40 MILLION TONS @0.51 CU, ? MO, 0.15 OPT AG

    MARGINAL ORE 30 MILLION TONS @0.32% CU, ? MO, AND 0.15 OPT AG

    POSSIBLE ORE 30 MILLION TONS@0.55% CU, ? MO, AND 0.15 OPT AG

Reference information

Bibliographic references

  • Deposit

    MILLER, R.N. SHEA, E.P., GODDARD, C.C. JR., POTTER, C.W., AND BROX, G.B., APRIL 1973, GEOLOGY OF THE HEDDLESTON COPPER-MOLYBDENITE DEPOSIT, LEWIS AND CLARK COUNTY, MT.: PROCEEDINGS OF THE 1973 PACIFIC NW MINING AND METALS CONFERENCE; American Institute of Mining, Metallurgical and Petroleum Engineers, Coeur d'Alene, Idaho.

  • General

    http://www.cbre.com/NR/rdonlyres/B8A28904-58AE-4CD5-B26A-BBD8289AF853/479303/HeddlestonTeaser.pdf (Information provided to prospective buyers of the property).

  • Deposit

    PARDEE, J.T. AND SCHRADER, F.C., 1933, METALLIFEROUS DEPOSITS OF THE GREATER HELENA MINING REGION: USGS BULL. 842, 318 p.

  • Deposit

    LAWSON, D.C., 1975, DIRECTORY OF MINING ENTERPRISES FOR 1974: MBMG BULLETIN 95, P. 14.

  • Deposit

    MELSON, W.G., 1964, GEOLOGY OF THE LINCOLN AREA, MONTANA AND CONTACT METAMORPHISM OF IMPURE CARBONATE ROCKS: PH. D. DISSERTATION, PRINCETON UNIVERSITY, 153 P.

  • Deposit

    MCCLERNAN, H.G., 1983, METALLIC MINERAL DEPOSITS OF LEWIS AND CLARK COUNTY, MONTANA: MBMG MEMOIR 52, 73 P.

  • Deposit

    RICHMOND, R.C., 1975, GEOLOGICAL EXPLORATION IN THE HEDDLESTON DISTRICT, MONTANA. PROCEDDINGS OF THE 1973 PACIFIC NWMINING AND METALS CONFERENCE, APRIL 1973. MONT. BUREAU OF MINES AND GEOL. BULLETIN 95, P. 14.

  • Deposit

    ROBERTSON, F., 1956, GEOCHEMICAL PROSPECTING BY SOIL ANALYSES IN MT, MT BUREAU OF MINES & GEOLOGY BULL. 7.

General comments

Subject category Comment text
General The Heddleston Copper Project consists of approximately 41 patented lode mining claims and 189 unpatented claims.
Deposit REC-040 27 MILES OF EXPLORATION/DEVELOPMENT ROADS CONSTRUCTE THAN 1 MILE OF GRAVELLED ROAD ACCESSES THE PROPERTY. MAKE UP WATER CAN BE SUPPLIED FROM WELLS LESS THAN 2 MILES DISTANT. A TRANSMISSION LINE LEADS TO THE PROPERTY FROM HWY 2 MILES DISTANT. REC-080 ATTITUDE AND DIMENSIONS PERTAIN TO THE MINERALIZED Z CONTAINED SECONDARY ENRICHED MINERAL DEPOSITS COMPRI HEDDLESTON COPPER-MOLYBDENUM PROPERTY. RECS-101-105 RESERVES/RESOURCES OF COMBINED DEPOSITS-ANACOND ESTIMATE. MILL RCVY ASSUMD. -84% CU, 53% MO. MILL CONC. ASSUMD.-25% CU, 57% MO. REC 160-161 CONC. DESTINATION-ANACONDA (217 KM). ASARCO ACQUIRED THE PROPERTY IN 1982. SINCE THAT TIME, ASSESSMENT WORK. THE COMPANY HAS NO PLANS TO PUT THE PROERTY INTO PRODUCTION IN THE NEAR FUTURE. IN SECTION 21 AND ALSO SECTION 29.
General This is the full text of the PDF reference. An aerial photos is missing from this description.
Heddleston Copper Project, Lewis and Clark County, Montana ASARCO, Incorporated is offering for sale its Heddleston Copper Project in Lewis and Clark County, Montana. The Heddleston Project is located in west central Montana, about 50 miles NW of Helena, and consists of a major Cu-Mo porphyry deposit.
The mineralization is a chalcopyrite-molybdenite Eocene instrusive complex which cuts Proterozoic belt sediments. The primary mineralization has been weathered and enriched, and at the surface consists of a chalcocite blanket overlying chalcopyrite.
The project consists of approximately 41 patented lode mining claims and 189 unpatented claims. Anaconda completed extensive RC, core and churn drilling of the project in the 1960?s and Asarco continued a drilling program into the 1990?s.

INVESTMENT HIGHLIGHTS:
? Total drilling database of 358 holes with over 250,000 feet of churn, RC and diamond drilling
? Current drill-indicated resource estimate of 125 million tons of ore at .49% Cu, .015% Mo and .15 opt Ag
? Potential to add at least another 50 million tons of ore to resource at peripheral areas
? Open pit minable resource combined with SXEW processing facilities
? Metallurgical testwork demonstrates 60% leach recoveries from chalcocite ores

Exclusively represented by:
Andrew A. Brodkey
Managing Director
T 520.323.5120
Andrew.Brodkey@cbre.com
www.cbre.com/imm
John T. Perry
Vice President & Director
T 520.323.5158
John.Perry@cbre.com
www.cbre.com/imm
General This deposit was centered around the Mike Horse Mine. Exploration was for large tonnage porphyry copper deposit, while original mining was of lead, gold,copper, and silver. Some information from the Mike Horse property has been consolidated into this record.

Reporter information

Type Date Name Affiliation Comment
Reporter 03-FEB-97 Spear, James M. U.S. Bureau of Mines
Reporter 01-NOV-74 Fisher, Fred S. U.S. Geological Survey This reporter created record D001594 in old MRDS database, which has been incorporated into this database.
Reporter 01-APR-76 Mlynarczyk, Meg S. U.S. Geological Survey This reporter created record W014720 in old MRDS database, which has been incorporated into this database.
Updater 18-DEC-09 Causey, J. Douglas U.S. Geological Survey Combined several records, which included Mike Horse Mine records.

Beyond USGS

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

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:

  • Asarco (American Smelting And Refining Co.) — acquired by Asarco LLC, subsidiary of Grupo México (2009)
    American Smelting and Refining Co. Filed Chapter 11 in 2005; acquired out of bankruptcy by Grupo México in 2009.

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.

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