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Golden Sunlight

Plant in Jefferson county in Montana, United States with commodities Copper, Gold, Silver
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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. Mineral occurrence model information
  9. Host and associated rocks
  10. Nearby scientific data
  11. Geologic structures
  12. Ore body information
  13. Controls for ore emplacement
  14. Economic information about the deposit and operations
  15. Mining district
  16. Mineral rights holdings
  17. Land status
  18. Ownership information
  19. Production statistics
  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 10148740
MRDS ID W014657
MAS/MILS ID 0300430151
Record type Site
Current site name Golden Sunlight
Alternate or previous names Golden Sunlight Mine and Plant, Sunlight, Golden Sunlight Group, Minera Hill, And Excelsior

Geographic coordinates

Point of reference Pit
Geographic coordinates: -112.01417, 45.8988 (WGS84)
Elevation 1646
Location accuracy 100(meters)

Site location context

Political divisions (FIPS codes)

Jefferson(county)

Montana(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Black Butte(quadrangle 1:24,000 scale)

Butte South(quadrangle 1:100,000 scale)

Dillon(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Jefferson(hydrologic unit)

Missouri Headwaters(hydrologic accounting unit)

Missouri Headwaters(hydrologic subregion)

Missouri(hydrologic region)

Federal lands

Bureau of Land Management(Bureau of Land Management MT)

Bureau of Land Management MT BLM(Type of land area)

BLM(Federal land areas administered by BLM)

Geographic areas

Country State County
United States Montana Jefferson

Public Land Survey System information

Meridian Township Range Section Fraction State
Montana Principal 002 N 003 W 19 NESESE Montana

Comments on the location information

  • THIS PROPERTY INVOLVES PORTIONS OF SECTIONS 19, 20, 28, 29 AND 30, T. 2N., R. 3W, MPM CORRECT MINES ID FORM 2401417 (PLACER AMEX INC.) TO MINES ID 2401040 (PLACER DOME INC.)

Commodities

Commodity Importance
Copper Tertiary
Gold Primary
Silver Tertiary

Comments on the commodity information

  • AURIFEROUS PYRITE ASSOCIATED WITH QUARTZ VEINS, MINERALIZING SOLUTIONS APPARENTLY INJECTED INTO IRREGULAR VEIN SYSTEM

Materials information

Materials Type of material
Chalcocite Ore
Chalcopyrite Ore
Covellite Ore
Tetrahedrite Ore
Gold Unknown
Pyrite Unknown
Silver Unknown

Mineral occurrence model information

Model code 84
USGS model code 22b
Deposit model name Alkaline Au-Te (Au-Ag-Te veins)
Mark3 model number 80

Host and associated rocks

  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Shale
    Rock unit name Belt Series, Greyson Shale
    Stratigraphic age (youngest) Early Pliocene
  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Latite
    Rock unit name Lamprophyre Dikes;Latite Porphyry Stock
    Stratigraphic age (youngest) Pliocene

Nearby scientific data

Pit (1) Gravel
ListMap

Economic information

Geologic structures

Type of structure Regional
Structure name Boulder Batholith, Lombard Overthrust
Type of structure Local
Structure name Golden Sunlight Fault Trends North - South And Dips 45 Deg E.

Ore body information

  • General form ELLIPSOIDAL SHAPE
    Length 500M
  • Strike N45W
    Dip 25E
    Thickness 200M
    Length 150M
    Width 100M
    Depth to top 0M
    Field Value
    MAS Matrix # 1
    MAS Column # 1
    Type of Orebody #1 BRECCIA FILL
    Shape of Orebody #1 PIPELIKE
    Type of Orebody #2 FISSURE VEIN
    Primary mode of Origin HYDROTHERMAL
    Primary Ore Control OTHER
    Degree of Wallrock Alter. INTENSE
    Strike And Dip N45W:25E
    Minimum Depth to Top 0
    Avg. Thick. Unconsol. Mat. 0
    Min. Thick. Unconsol. Mat. 0
    Date of Last Modification 830826
  • Area 2359HA
    Field Value
    Total Surface Area (HA) 2359
    Date of Last Modification 910418

Controls for ore emplacement

  • Latite Porphyry Intrusion, Golden Sunlight Fault May Be Ore Control

Comments on the geologic information

  • MANY FAULTS CUT BOTH THE IGNEOUS AND SEDIMENTARY ROCKS. A PIPELIKE BODY OF SILICA-CEMENTED SHALE OCCURS AT THIS DEPOSIT. THE CORE OF THE MINERALIZED ZONE IS CENTERED AROUND THE BRECCIA PIPE. HYDROTHERMAL ALTERATION WITHIN AND SURROUNDING THE BRECCIA PIPE IS EVIDENCED BY SILICIFICATION AND SERICITATION. FREE GOLD IS REPORTED WITH MINOR SILVER. PYRITE IS THE DOMINANT SULFIDE.
  • THE PROTEROZOIC SEDIMENTARY ROCKS CONTAIN SYNSEDIMENTARY MINERALIZATION IN THE FORM OF HIGH-SULFIDE HORIZONS AND FINELY DISSEMINATED DIAGENETIC MINERALIZATION. AUTHIGENIC K-SPAR IS ALSO PRESENT. SAMPLES OF THE SYNSEDIMENTARY MINERALIZATION THAT APPEAR NOT TO HAVE BEEN AFFECTED BY THE EPIGENETIC PROCESSES CARRY LOW-LEVEL GOLD IN THE 0.01 OZ/TON (0.031 G/TONNE) RANGE. THIS SUGGESTS THAT THE GOLD WAS DEPOSITED WITH THE SYN-SEDIMENTARY SULFIDES. THIS LOW-LEVEL GOLD MAY HAVE SERVED AS THE SOURCE FOR SOME OF THE METALS IN THE EPIGENETIC BRECCIA PIPE. THE SIMILAR MULTIELEMENT SIGNATURE BETWEEN THE SYNSEDIMENTARY SYSTEM AND BRECCIA PIPE ALSO SUPPORTS THE POSSIBILITY OF EPIGENETIC REMMOBILIZATION OF METALS. (FOSTER AND SMITH, 1995)

Economic information about the deposit and operations

Operation type Surface
Development status Plant
Commodity type Metallic
Deposit size Small
Significant Yes
Discovery year 1890
Mining method Open Pit
Year of first production 1983
Plant type Leach
Plant subcategory Hydromet
Milling method Carbon-In-Pulp-Electrowin

Mining district

District name Cardwell

Mineral rights holdings

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

Land status

Ownership category Private

Ownership information

  • Type Owner
    Owner Placer Dome Inc.
    ID 2401040
    Interest 100
    Home office Canada
    Year 1995
    First year 1990
  • Type Operator
    Owner Golden Sunlight Mines, Inc.
    Home office Montana
    Year 1995
    First year 1990

Production statistics

  • Year 1910
    Period 1890-1910
    Description 1890-1910 Gross Value $1,500,000 68000 Metric Tonnes Ore
  • Year 1917
    Period 1910-1917
    Description 1910-1917 Gross Value 200,000 4 Metric Tonnes Ore
  • Year 1935
    Period 1917-1935
    Description 1917-1935 Gross Value 226,000 9 Metric Tonnes Ore
  • Year 1936
    Description Gross Value $149,747 4 Metric Tonnes Ore
  • Year 1937
    Description Gross Value 29,394 1 Metric Tonnes Ore
  • Year 1938
    Description Gross Value 55,440 3 Metric Tonnes Ore
  • Year 1939
    Description Gross Value 276,311 13199 Metric Tonnes
  • Year 1940
    Description Gross Value 72,435 4 Metric Tonnes Ore
  • Year 1941
    Description Gross Value 108,233 4 Metric Tonnes Ore
  • Year 1942
    Description Gross Value 156,692 14 Metric Tonnes Ore
  • Year 1943
    Description Gross Value 185,267 14 Metric Tonnes Ore
  • Year 1944
    Description Gross Value 177,004 13 Metric Tonnes Ore
  • Year 1945
    Description Gross Value 106,882 9199 Metric Tonnes Ore
  • Year 1983
    Description Ore Containing 1.69 Gm/Mt Au 1555000 Metric Tonees Ore
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Gold Gold 2g/mt
  • Year 1984
    Description Ore Containing 1.65 Gm/Mt Au 1864000 Metric Tonnes Ore
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Gold Gold 2g/mt
  • Year 1985
    Description Ore Containing 1.65 Gm/Mt Au 1972000 Metric Tonnes Ore
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Gold Gold 2g/mt
  • Year 1986
    Description Ore Containing 1.611 G/Mt Au 2106000 Mt/Ore
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Gold Gold 2g/mt
  • Year 1992
    Description Gold 103870 T Oz/Yr Au
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Gold Gold 3230718.57g
  • Year 1993
    Description Gold 121618 T Oz/Yr Au
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Gold Gold 3782743.15g
  • Year 1994
    Description Gold 50097 T Oz/Yr Au
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Gold Gold 1558191.08g
  • Year 1995
    Description Ore Mill Feed @ 1.79 G/Mt Au 2027000 Mt Ore
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Gold Gold 2g/mt
  • Year 1995
    Description Gold Production 89799 Tr Oz/Yr
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Gold Gold 2793061.49g
  • Year 1996
    Description Gold Production 117931 Tr Oz/Yr
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Gold Gold 3668064.61g
  • Year 1996
    Description Ore Mill Feed @ 2.06 G/Mt Au 2283000 Mt Ore
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Gold Gold 2g/mt

Comments on the production information

  • 1989 PROD.= 111,539 OZ. AU. FROM 2,268,000 MT ORE TREATED.
  • MILLING BY SIZE REDUCTION, THEN CYANIDE VAT LEACH (12 400,000 GALLON LEACH TANKS), WASHING AND TREATMENT OF SLIME FRACTION BY CARBON ADSORPTION USING CARBON-IN-PULP TANKS AND UP-FLOW CARBON COLUMNS. THE GOLD IS REMOVED FROM THE CARBON IN PRESSURE STRIPPING VESSELS USING A CAUSTIC CYANIDE SOLUTION. THE SAND FRACTION GOES TO A SAND TAILING RETREATMENT USING GRAVITY CONCENTRATION IN SPIRAL SHAPED LAUNDERS.

Reserves and resources

  • Type In-situ
    Estimate year 1986
    Inferred 17963000mt ore
    Total resources 17963000mt ore
    Commodity Subtype Grade units Group Importance Year
    Gold Au 1.65 g/mt Gold Major 1986
  • Type In-situ
    Estimate year 1995
    Demonstrated 42759000mt ore
    Commodity Subtype Grade units Group Importance Year
    Gold Au 1.9 g/mt Gold Major 1995
  • Type In-situ
    Estimate year 1995
    Demonstrated 8124000mt ore
    Commodity Subtype Grade units Group Importance Year
    Gold Au 1.4 g/mt Gold Major 1995
  • Type In-situ
    Estimate year 1995
    Demonstrated 32451000mt ore
    Commodity Subtype Grade units Group Importance Year
    Gold Au 1.9 g/mt Gold Major 1995
  • Type In-situ
    Estimate year 1996
    Demonstrated 19669000mt ore
    Commodity Subtype Grade units Group Importance Year
    Gold Au 2.4 g/mt Gold Major 1996
  • Type In-situ
    Estimate year 1996
    Demonstrated 28575000mt ore
    Commodity Subtype Grade units Group Importance Year
    Gold Au 1.5 g/mt Gold Major 1996
  • Type In-situ
    Estimate year 1996
    Demonstrated 48244000mt ore
    Commodity Subtype Grade units Group Importance Year
    Gold Au 1.87 g/mt Gold Major 1996

Comments on the reserve resource information

  • PUBLISHED RESERVES CONTAIN 0.05 OZ AU/T; 0.05 OZ/X GM = 1 GM/0.03215 TR OZ = 1.56 GM. 1989 RESERVE = 2,007,000 OZ. CONT. AU. 1994 RESERVES FROM PERSONAL COMM W/ D.J.WILSON, MINE MGR.
  • RECOVERABLE IDENTIFIED RESERVES INCUDE A 5% DILUTION RATE. TOTAL GEOLOGIC RESERVES ARE 46,100,000 MT WITH A WEIGHTED AVERAGE GRADE OF 2.05 GM AU/MT. INCLUDED IN THIS CATEGORY ARE 22,700,000 MT OF MATERIAL GRADING 2.40 GM AU/MT. THESE RESERVES WILL REQUIRE UNDERGROUND MINING AND ARE NOT PRESENTLY RECOVERABLE WITHOUT A SUBSTANTIAL INCREASE IN THE PRICE OF GOLD.
  • TOTAL DEMON. RESERVES, 12/31/96: ("R" RECORD 7 ("R" RECORDS 5 + 6)). PROVEN + PROBABLE + MEASURED + INDICATED ORE:
  • PRODUCTION 1890 TO 1945 ESTIMATED AT 154,308 TONS, AVERAGING 0.373-OZ GOLD AND 0.51-OZ SILVER PER TON. AN ADDITIONAL 55,503-POUNDS COPPER WAS RECOVERED FROM SHALLOW COPPER-OXIDE ROCKETS (LASMANIS, R., 1972).



    A NEWSPAPER ARTICLE STATED THAT FROM 1901 TO 1980, A TOTAL OF 253,618 TONS OF ORE WAS PRODUCED; 59,271 OUNCES OF GOLD; 80,061 OUNCES OF SILVER; AND 54,598 POUNDS OF COPPER (MONTANA STANDARD, MARCH 8, 1981).



    1989-TOTAL RESERVES INCLUDING THOSE MINED SINCE 1983 STOOD AT 53 MILLION SHORT TONS GRADING 0.05 OGT WITH A 6.5:1 OVERALL STRIP RATIO. FROM 1983 THROUGH DECEMBER 1988, APPROXIMATELY 13,100,000 TONS GRADING 0.05 OGT WERE MINED OF THIS RESERVE, PRODUCING APPROXIMATELY 550,000 OUNCES OF GOLD.



    60% OF THE GOLD RESERVES OCCUR IN THE BRECCIA, AND THE REMAINING ORE IN THE IMMEDIATELY ADJACENT COUNTRY ROCK. MINERALIZATION IS BOTH DISSEMINATED AND STRUCTURALLY CONTROLLED, AND THE TWO STYLES COMMONLY OVERLAP. DISSEMINATED MINERALIZATION OCCURS IN THE SULPHIDIC MATRIX OF THE BRECCIA, AND IN DISSEMINATED SULPHIDES IN THE LATITE PORPHYRY AND PROTEROZOIC ROCKS. STRUCTURALLY-CONTROLLED MINERALIZATION OCCURS ALONG FAULTS AND SULPHIDE-FILLED VEINS AND JOINTS. DISSEMINATED MINERALIZATION COMMONLY CARRIES 0.0X OGT (OUNCES GOLD PER TON) WHEREAS 0.X OGT IS COMMON IN STRUCTURALLY CONTROLLED ZONES. MINERALIZED STRUCTURES CUT ALL ROCK TYPES, INCLUDING BRECCIA. THREE DOMINANT STEEPLY-DIPPING STRUCTURAL TRENDS ARE PRESENT. IN DECREASING FREQUENCY THEY ARE: NORTHEAST, NORTHWEST, AND NORTH-NORTHWEST. (FOSTER, 1989).



    1995- PUBLISHED RESERVES (INCLUDING THOSE MINED SNCE START UP) TOTAL 70.8 MILLION SHORT TONS GRADING 0.054 OUNCES PER TON GOLD (3,823,000 OUNCES). (FOSTER AND SMITH, 1995). APPROXIMATELY 57,000 OUNCES OF GOLD (154,000 TONS AVERAGING 0.371 OUNCES OF GOLD PER TON) WERE PRODUCED FROM THE GOLDEN SUNLIGHT PRIOR TO 1958. (FOSTER AND OTHERS, 1995)



    1996- 19,669,000 TONNES WITH 2.4 G/T GRADE CONTAINING 47600.0 KG GOLD OR 1,530,000 OUNCES GOLD (FROM A PLACER DOME INC. ANNUAL REPORT).

Workings at the site

  • Type of workings Surface
    Area 2359HA
    Field Value
    MAS Development Schedule # 1
    Mining Record # 1
    Status of Mining Method ESTIMATE
    Mining Method OPEN PIT
    Percent Waste Rock 99.9
    Avg. Overburden Thickness 0
    Primary Material Cover M-HARD ROCKS
    Hardness of Ore M-HARD ROCKS
    Avg. Bench Height (meters) 7.5
    Capacity 4540
    Capacity Units MT ORE/DAY
    Unit Production Cost 1.67
    Units of Production $/MT ORE
    Operating Days per Year 260
    Operating Shifts per Day 2
    Year of Information 1982

Comments on other economic factors

  • 1983-1987 2.8 MT AU/YR X $30,000/MT X 1 YR/52 SHIPMENTS X 1 SHIPMENT/1425 KM = $1.13/MT/KM. 1988-1996 COSTS = $1.30 MT/KM. (3.21 MT BULLION/YR.).
  • OPERATING CAPACITY WILL BE UP TO 100% IN LATER YEARS AS SOFTER, EASIER MILLING ORES ARE ENCOUNTERED.
  • FROM 1983 TO 1990, STRIP RATIO WAS ABOUT 2:1. FROM 1990 TO 2003, A CHANGE IN THE MINING PLAN INCLUDES 5 STAGES HAVING AN OVERALL STRIP RATIO OF 7.45:1. THE AMOUNT OF WASTE GIVEN REFLECTS LATTER RATIO. S-UPC INITIALLY WILL BE $1.68/MT ORE IN 1983, BUT WILL RISE TO $2.90/MT ORE BY 1990.
  • MINE EQUIPMENT LIST - 1983 DESCRIPTION QUANTITY TRUCKS-WABCO 60 ST 5 WATER TRUCK 1 D8 BULLDOZERS 2 D6 DOZER (TAILINGS) 1 988B FRONT END LOADER 1 14G GRADER 1 AIR TRACK DRILL 1 D40K 6 DRILL 1 ANFO TRUCK 1 BE 155B 8 YD ELECTRIC SHOVEL 1 WHEN THE MINE REACHS FULL PRODUCTION, THERE WILL BE 13 TRUCKS IN THE FLEET, AND 3 155B ELECTRIC SHOVELS.
  • GOLDEN SUNLIGHT TEMPORARILY CEASED MILLING OPERATION FROM 6/14/94 TILL 2/6/95 DUE TO GROUND MOVEMENT.

Comments on development

  • PROPERTY DEVELOPED BY AT LEAST 15 ADITS AND PITS AND SEVERAL SURFACE CUTS ON EAST SIDE OF RIDGE INCLUDING THE ?BACORN? LEVEL OR ADIT AND THE ?OHIO? LEVEL OR ADIT.



    EARLY MINING WAS PREDOMINANTLY BY UNDERGROUND WORKINGS. OPEN-PIT STARTED IN 1981 TO PRESENT (2000). SLATED FOR CLOSURE IN 2002 (AS OF 06/2000).
  • 1890- FIRST CLAIMS STAKED BY A.H. HEDLEY.

    1890-AMERICAN DEVELOPMENT AND MINING CO. ACQUIRED HEDLEY?S CLAIMS AND STAKED CLAIMS ON MINERAL HILL.

    1895-STAMP MILL CONSTRUCTED BY AMERICAN DEVELOPMENT; MILLING EFFORTS NOT SUCCESSFUL; ABANDONED IN 1905.

    1890-1910-ORE SHIPPED TO SMELTERS FROM ?OLD SUNLIGHT? WORKINGS. ESTIMATED PRODUCTION FOR THIS PERIOD IS 75,000 TONS OF ORE HAVING A GROSS VALUE OF $1,500,000.

    1904-PROPERTY SOLD TO EUGENE RING OF BUTTE

    1906-40-TON CYANIDE MILL WAS BUILT; ABANDONED BEFORE 1910.

    1910-1917-PROPERTY ACQUIRED BY H.C. BACORN AND ASSOCIATES.

    1917-1935-PROPERTY MINED ON SMALL SCALE BY LESSEES.

    1920-J.B. WELLCOME AND ALEX MCKAY GAINED CONTROL OF THE PROPERTY; LATER, THEIR HEIRS GIVE ANACONDA COMPANY OPTION TO PURCHASE THE PROPERTY. ANACONDA DECLINES AFTER EXPLORATION IN 1935.

    1936/1937-A.O. SMITH OBTAINS LEASE AND OPTION TO PURCHASE SUNLIGHT HOLDINGS FROM WELLCOME AND MCKAY HEIRS.

    1938-PRODUCTION OF A SMALL AMOUNT OF DIRECT SHIPPING ORE.

    1939-SMITH SUB-LEASES THE PROPERTY; LESSEES SHIP SMALL QUANTITIES OF ORE UNTIL 1946.

    1946-MARTIN BROTHERS TEST PROPERTY AND GIVE UP OPTION TO PURCHASE.

    1955-56 WHITE DEVELOPMENT CO. ATTEMPT TO OPERATE THE MINE AS A MODERATE-VOLUME OPEN-PIT OPERATION. GLORY HOLE AND A CONNECTING CONVEYOR BELT HAULAGE ADIT DEVELOPED ON MINERAL HILL TO MINE LOW-GRADE ORE BODY CENTERED AROUND BRECCIA PIPE.

    1958-AMERICAN EXPLORATION AND MINING CO. (PLACER U.S.) OPTIONS PROPERTY (PREDECESSOR OF GOLDEN SUNLIGHT MINES) FROM A.O. SMITH CORP.

    1968-PLACER U.S. PURCHASES PROPERTY

    1981-CONSTRUCTION OF FACILITIES STARTED.

    FEBRUARY 1983, FIRST GOLD POURED AFTER A $50 MILLION CAPITAL INVESTMENT.

    MID-1994-1995 7.5 MONTH HIATUS IN PRODUCTION DUE TO RE-ACTIVATED LANDSLIDE.

Reference information

Bibliographic references

  • Geology

    Porter E W, Ripley E 1985 - Petrologic and stable isotope study of the Gold-bearing breccia pipe at the Golden Sunlight deposit, Montana: in Econ. Geol. v80 pp 1689-1706

  • Reference

    MINE/DEPOSIT FILE REPORT, PLACER AMEX, INC., GOLDEN SUNLIGHT

  • Geology

    Spry P G, Paredes M M, Foster F, Truckle J S, Chadwick T H 1996 - Evidence for a genetic link between Gold-Silver Telluride and Porphyry Molybdenum mineralization at the Golden Sunlight deposit, Whitehall, Montana: fluid inclusion and stable isotope studies: in Econ. Geol. v91 pp 507-526

  • Reference

    PROPERTY, WHITEHALL, MT, FINAL REPORT, USBM CONTRACT NO.

  • Reference

    SO221028, DEC. 1982.

  • Reference

    MONTANA DEPT. OF STATE LANDS, DRAFT ENVIRONMENTAL IMPACT

  • Reference

    STATEMENT, PROPOSED PLAN OF MINING AND RECLAMATION, PLACER

  • Reference

    AMEX, INC. JEFFERSON CO., MT, 60 PP., NO DATE GIVEN.

  • Reference

    MINING CONGRESS JOURNAL, OCT. 1981.

  • Reference

    PLACER DEVELOPMENT, LTD., 1981 ANNUAL REPORT, P. 3.

  • Reference

    AGETEN, R.W., KREMPASKY, G.T., AND RICE, W.L., A SYSTEMS

  • Reference

    APPROACH TO RECOVERING GOLD RESOURCES IN JEFFERSON CO., MT,

  • Reference

    BUMINES RI 7305, OCT., 1969, 16 PP.

  • Reference

    SKILLINGS MINING REVIEW. PLACER AMEX OPERATING GOLDEN SUN-

  • Reference

    LIGHT MINE AT FULL CAPACITY, JUNE 18, 1983, PP. 4-9.

  • Reference

    MSHA RPT DATED APRIL, 1981.

  • Reference

    MBM & G MEM 31, 1950, P. 40.

  • Reference

    MBM & G MEM 20, 1940, P. 38.

  • Reference

    E&MJ MINING ACTIVITY DIGEST V. 9, NO. 8, JAN 15, 1983, P.1.

  • Reference

    E&MJ LEACHING AND PRECIPITATION TECHNOLOGY FOR GOLD AND

  • Reference

    SILVER ORES, JUNE 1983, PP. 48-56.

  • Production

    PLACER DOME INC., 1996 FORM 4O-F REPORT, P13.

  • Reserve-Resource

    SWEENEY, 1986, PLACER DOME, 1986.

  • Reserve-Resource

    PLACER DOME INC., NEWS RELEASE, 2/24/95, P.3.

  • Reserve-Resource

    PLACER DOME INC., 1994 ANNUAL REPORT, P16.

  • Reserve-Resource

    PLACER DOME INC., 1995 FORM 10-K, P12.

  • Reserve-Resource

    PLACER DOME INC., 1996 FORM 10-K, PP. 14, 15, 23, 24.

  • Deposit

    PLACER DOME INC FORM 10K FOR 1989.

  • Deposit

    PLACER DOME INC ANNUAL REPORT FOR 1989.

  • Deposit

    MONT. BUREAU OF MINES AND GEOL. BULLETIN 129, 1991,

  • Deposit

    MONTANA STANDARD. ENVIRONMENTALISTS SUE GOLDEN SUNLIGHT.

  • Deposit

    MARCH 31, 1992.

  • Deposit

    ASSOCIATED PRESS. MINE TRIES MANY TRICKS TO SAVE BIRDS

  • Deposit

    REVIEW, JUNE 1, 1992.

  • Deposit

    MONTANA STANDARD. DYING BIRDS TARNISH GOLDEN SUNLIGHT

  • Deposit

    IMAGE. JUNE 2, 1992.

  • Deposit

    CHAPIN, PETER. ENVIRONMENTALISTS ANSWER GOLDEN SUNLIGHT

  • Deposit

    CRITICISM. MONTANA STANDARD. JUNE 4, 1992, P. 2.

  • Deposit

    MCMILLION, SCOTT. GOLDEN SUNLIGHT MINE WINS PRELIMINARY

  • Deposit

    ROUND. BOZEMAN DAILY CHRONICLE. JUNE 29, 1992.

  • Deposit

    PLACER DOME INC., NEWS RELEASE, 2/7/95, 1PP.

  • Deposit

    MINING RECORD, V 106/N 7, 2/15/95, P.1.

  • Deposit

    MINING RECORD, V 106/N 17, 4/26/95, P.1,10.

  • Deposit

    PLACER DOME INC., NEWS RELEASE, 6-16-94, 9-7-94.

  • Deposit

    PLACER DOME INC., NEWS RELEASE, 8-9-96.

  • Deposit

    PLACER DOME INC., PRESS RELEASE 2-26-96.

  • Deposit

    PLACER DOME INC., 1995 FORM 10-K, 12-31-95, PP. 12, 20.

  • Deposit

    PLACER DOME INC., 1995 ANNUAL REPORT.

General comments

Subject category Comment text
Deposit ORE IN IRREGULAR VEIN SYSTEM. MINERALIZED AREA HAS ELLIPSOIDAL SHAPE WITH NORTH - SOUTH AXIS OF 1400 FT, EAST - WEST AXIS OF 600 FT AND DEPTH OF 400 FT.



THE GOLDEN SUNLIGHT IS CURRENTLY INTERPRETED AS A SHALLOW EPIGENETIC EPITHERMAL SYSTEM, LIKELY TO BE FORMED IN RESPONSE TO LATITE PORPHYRY MAGMATISM. BRECCIA FORMATION APPEARS TO HAVE BEEN A PASSIVEPROCESS, ESSENTAILLY CRACKING THE HOST ROCKS IN PLACE WITHOUT CONSIDERABLE CLAST TRANSPORTATION. THE WATER TO WALLROCK RATIO APPEARS TO HAVE BEEN LOW, HYDROTHERMAL METASOMATISM WAS WEAK, AND THE SYSTEM MAY HAVE BEEN CAPPED BY SILICA CONDENSATE. MINERALIZING FLUIDS WERE COOL AND DILUTE. (FOSTER, 1989).
General ?THE MINE IS CENTERED ON A SILICEOUS BRECCIA PIPE WHICH CONTAINS DISSEMINATED MINERALIZATION THAT EXTENDS MORE THAN 100 FEET INTO THE WALLROCK IN SILICIFIED FRACTURES. THE PIPE IS AN IRREGULAR OVAL, APPROXIMATELY 700 FEET IN DIAMETER, WHICH PLUNGES 35 DEGREES TO THE WEST. INDIVIDUAL BRECCIA FRAGMENTS MAY BE GREATER THAN 30 FEET IN SIZE AND CONSIST OF ALL ROCK TYPES EXCEPT FOR THE LAMPROPHYRES.? ?GOLD OCCURS AS DISSEMINATED PARTICLES ASSOCIATED WITH THE PYRITE IN THE BRECCIA MATRIX, AURIFEROUS PYRITE, AND MINOR TELLURIDE MINERALS. SUPERIMPOSED ACROSS THE BRECCIA PIPE AND INTO THE SURROUNDING WALL ROCK ARE NORTHEAST TRENDING GOLD-QUARTZ VEINS THAT MAY CONTAIN PYRITE, GALENA, SPHALERITE, AND BARITE (PORTER AND RIPLEY, 1985). THE EXISTING PIT WALL ROCK IS COMPOSED PRIMARILY OF TERTIARY LATITE PORPHYRY, AND GREYSON AND NEWLAND FORMATIONS OF THE BELT SUPERGROUP.? (FROM ENVIRONMENTAL ASSESSMENT, MDSL, MAY 30, 1990).



?GOLD MINERALIZATION OCCURS WITHIN AND AROUND A PIPE-SHAPED BRECCIA WHICH CUTS THE PROTEROZOIC ROCKS AND LATITE PORPHYRY. THE BRECCIA IS APPROXIMATELY 700 FEET IN DIAMETER, AND PLUNGES 35 DEGREES TO THE WEST-SOUTHWEST. OVER 1,200 VERTICAL FEET OF BRECCIA HAVE BEEN DRILLED , AND IT REMAINS OPEN AT DEPTH. THE MINERALIZED BRECCIA CONTAINS LATITE CLASTS AND IS CUT BY THE POST-MINERAL LAMPROPHYRE DIKES, THEREBY BRACKETING THE AGE OF MINERALIZATION AS YOUNGER THAN THE LATITE AND OLDER THAN LAMPROPHYRE MAGMATISM.? (FOSTER, 1989).



?MUCH OF THE 5,000 TO 8,000 FOOT-THICK PROTEROZOIC SECTION HERE IS INTERPRETED AS A PROGRADATIONAL BASIN PLAIN/SUBMARINE FAN/SLOPE COMPLEX. SHELF AND ALLUVIAL DEPOSITS OVERLIE THE COMPLEX IN THE NORTHERN AND SOUTHERN PART OF THE AREA, RESPECTIVELY.? (FOSTER AND OTHERS, 1995).
General TWO MAJOR NORTHERLY-TRENDING, HIGH-ANGLE NORMAL FAULTS, THE ST.PAUL FAULT TO THE WEST AND GOLDEN SUNLIGHT FAULT TO THE EAST OF THE PIT, FORM A HORST WITHIN WHICH THE PROJECT AREA IS LOCATED. IT IS A CONTINUOUS STRUCTURE STRIKING NORTH-SOUTH AND THEN, SOUTH OF THE PIT, BENDING TO THE SOUTHWEST. MINOR EAST-WEST NORMAL AND REVERSE FAULTS TRANSECT THE HORST AND CUT THE GOLDEN SUNLIGHT AND ST. PAUL FAULTS. TWO SETS OF FRACTURES ARE EVIDENT IN THE AREA. ONE SET PARALLELS THE GOLDEN SUNLIGHT FAULT AND THE OTHER TRENDS NORTHEAST TO SOUTHWEST. (FROM ENVIRONMENTAL ASSESSMENT BY DEPARTMENT OF STATE LANDS, HELENA, MAY 30, 1990)



THE PRECAMBRIAN SEDIMENTARY ROCKS IN THE VICINITY OF THE GOLDEN SUNLIGHT MINE FORM A HOMOCLINE, WITH BEDS STRIKING NORTHWESTERLY AND DIPPING 15 DEGREES TO 35 DEGREES NORTHEAST; A FEW LOCAL, SMALL-SCALE FLEXURES OR ROLLS OCCUR IN THE SHALES. (AGETON AND OTHERS, 1969).
Deposit Merged data from Deposit ID 10071326 (Golden Sunlight Group)
General SERICITIC ALTERATION OF ALL BUT THE LATER LAMPROPHYRE DIKES (RAMBOSEK, 1946).



ALTERATION CONSISTS OF PYRITIZATION, SILICIFICATION AND DECARBONIZATION WITH AN ALTERATION MINERAL ASSEMBLAGE CONTAINING SILICA, PYRITE, BARITE, SERICITE, CHALCOPYRITE, GALENA, SPHALERITE, AND MOLYBDENITE (ENVIRONMENTAL ASSESSMENT, MDSL, MAY 30,1990).



THE BRECCIA IS SURROUNDED BY PERVASIVE WHITE CLAY/PYRITE ALTERATION. THE UPPER PORTIONS OF THE BRECCIA (NOW MINED OUT) CONTAINED STRONG SILICA FLOODING. THE CURRENTLY EXPOSED (DEEPER) PORTION OF THE BRECCIA LACKS THIS STONG METASOMATISM. HERE, STRUCTURALLY CONTROLLED MINERALIZATION CONSISTS OF MASSIVE SULPHIDE INFILLINGS WITH LITTLE OR NO ALTERATION HALOES. FELDSPAR-DESTRUCTIVE ALTERATION IN LATITE IS EXTREMELY VARIABLE AND RANGES FROM INCIPIENT CLAY DUSTINGS TO PERVASIVE REPLACEMENT, BUT FELDSPAR GRAINS ARE ALWAYS EASILY RECOGNIZABLE. SILICA FLOODING IS WEAK, AND THE INTENSITY OF ARGILLIZATION IS SIMILAR TO THAT FOUND IN SURROUNDING ROCKS. (FOSTER, 1989)



THE MINE IS SITUATED CENTRALLY WITH RESPECT TO A DISTRICT-SCALE PORPHYRY STYLE METAL ZONATION CONSISTING OF AN AU-MO CORE HALOED BY AG-PB, THEN MN. POTASSIC ALTERATION AND MOLYBDENITE MINERALIZATION OCCUR IN THE FELSIC INTRUSION. THE BRECCIA PIPE APPEARS TO BE GENETICALLY RELATED TO A MOLYBDENUM PORPHYRY SYSTEM AT DEPTH. THE DISTRICT-SCALE ALTERATION CONSISTS OF WIDESPREAD BLEACHING AND PYRITIZATION, AND LOCAL SILICIFICATION. HOWEVER, TYPICAL PHYLLIC AND PROPYLITIC PORPHYRY-STYLE ALTERATION ZONATION HAS NOT BEEN RECOGNIZED. THIS MAY BE DUE TO THE PHYSICAL AND CHEMICAL CHARACTER OF THE NONREACTIVE SILICICLASTIC HOST ROCKS THAT DID NOT FRACTURE WELL AND INHIBITED FLUID FLOW. ALSO, THE SHALLOW DEPTH OF EMPLACEMENT MAY HAVE CAUSED RAPID COOLING AND PERHAPS ALLOWED AN INFLUX OF METORIC WATERS TO RAPIDLY TERMINATE THE HYDROTHERMAL SYSTEM. (FOSTER AND SMITH, 1995)

Reporter information

Type Date Name Affiliation Comment
Reporter 14-OCT-97 Buckingham, David A. U.S. Bureau of Mines

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:

  • Placer Dome Inc. — acquired by Subsidiary of Barrick Gold (2006)
    Acquired by Barrick Gold in 2006.

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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