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Nighthawk Ridge Mine

Producer in White Pine county in Nevada, United States with commodities Gold, Silver, Mercury, Thallium, Antimony, Barium-Barite
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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. Ownership information
  18. Links to other databases
  19. Bibliographic references
  20. General comments
  21. Reporter information

Geologic information

Identification information

Deposit ID 10047584
MRDS ID M242961
Record type Site
Current site name Nighthawk Ridge Mine
Alternate or previous names Easy Junior
Related records 10310405, 10310554

Geographic coordinates

Geographic coordinates: -115.67422, 39.18104 (WGS84)
Elevation 1993
Relative position 30 MILES SE OF EUREKA, NV.

Site location context

Political divisions (FIPS codes)

White Pine(county)

Nevada(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Green Springs NW(quadrangle 1:24,000 scale)

Mount Hamilton(quadrangle 1:100,000 scale)

Ely(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Hot Creek-Railroad Valleys(hydrologic unit)

Central Nevada Desert Basins(hydrologic accounting unit)

Central Nevada Desert Basins(hydrologic subregion)

Great Basin(hydrologic region)

Federal lands

Bureau of Land Management(Bureau of Land Management NV)

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

BLM(Federal land areas administered by BLM)

Geographic areas

Country State County
United States Nevada White Pine

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 15N 56E 9 Nevada

Comments on the location information

  • AT NORTHERN END OF RAILROAD VALLEY AT THE SOUTHEAST END OF CORTEZ TREND.

Commodities

Commodity Importance
Gold Primary
Silver Secondary
Mercury Tertiary
Thallium Tertiary
Antimony Critical Tertiary
Barium-Barite Critical Tertiary

Comments on the commodity information

  • AU:AG RATIOS GENERALLY > 50:1.

Materials information

Materials Type of material
Barite Gangue
Hematite Gangue
Limonite Gangue
Opal Gangue

Alteration

  • (Local) Silicification, Jasperization, Argillization, Decarbonization. Silicification Is The Most Common Alteration Within The Orebody. Chainman Shale And Pilot Shale Are Argillized And Silicified Adjacent To Nighthawk Fault.

Mineral occurrence model information

Model code 172
USGS model code 26a
Deposit model name Carbonate-hosted Au-Ag
Mark3 model number 15

Host and associated rocks

  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Shale
    Rock unit name Chainman Shale;Joana Limestone
    Rock description Chainman Shale;Joana Limestone
    Stratigraphic age (youngest) Mississippian
  • Host or associated Host
    Rock type Sedimentary Rock > Carbonate > Limestone

Nearby scientific data

(1) -115.67422, 39.18104
ListMap

Economic information

Geologic structures

Type of structure Regional
Structure description Low Amplitude, Open Folds With Axes That Strike Between N-S And N15e.
Type of structure Local
Structure description Nighthawk Fault.

Ore body information

  • Length 762M
    Width 213.36M

Controls for ore emplacement

  • Nighthawk Fault Strikes Northeast, Dips 80 Degrees West And Serves As The Primary Conduit For Mineralizing Fluids. Ore Is Thickest Where Nighthawk Fault Is Offset By Wnw En Echelon Faulting, A Result Of Secondary Porosity In Chainman Shale At The Fault Intersections. Joana Limestone Acted As A Porous Host Since Gold Mineralization Appears Stratabound And Closely Emulates The Fold Pattern.

Economic information about the deposit and operations

Development status Producer
Commodity type Both
Deposit size Small
Significant No
Discovery year 1986
Discoverer Tenneco Minerals Co.
Year of first production 1989

Mining district

District name White Pine District (Closest); Cortez Trend

Ownership information

  • Type Joint Venture
    Owner Alta Bay Joint Venture
    Interest 100
  • Type Joint Venture Owner-Op
    Owner Alta Gold Co.
    Interest 60
    Home office 2319 Foothill Drive #140, Salt Lake City, Utah, 84109
  • Type Joint Venture Owner-Op
    Owner Echo Bay, Ltd.
    Interest 40

Comments on the reserve resource information

  • ESTIMATE CALCULATED USING A CUTOFF OF 0.009 OPT AU.
  • THE GEOLOGIC INVENTORY OF GOLD IN THE HYDROTHERMAL SYSTEM IS OVER 400,000 OUNCES, BUT MUCH OF THE MINERALIZATION IS BEYOND ECONOMIC MINING DEPTHS.

Comments on development

  • THE ORIGINAL EASY JUNIOR CLAIMS STAKED IN 1979 BY EARTH RESOURCES CO. ON THE BASIS OF PROMINENT JASPEROID OUTCROPS. THESE CLAIMS WERE ACQUIRED BY HOUSTON INTERNATIONAL MINERALS CO. IN 1980. HIMCO DRILLED EIGHT HOLES TOTALLING 1810 FT. IN 1980, BUT ONLY ONE HOLE CONTAINED ANOMALOUS GOLD MINERALIZATION. HIMCO SUBLEASED EASY JUNIOR TO CONSOLIDATED MINERAL RESOURCES 1981-1983, DURING WHICH EIGHT HOLES TOTALLING 2620 FT. WERE DRILLED. DRILL RESULTS WERE DISCOURAGING. IN 1984, CONSOLIDATED MINERALS CONVEYED INTEREST IN EASY JUNIOR TO AAMINEX FOR STOCK, AND AAMINEX SUB-LEASED THE PROPERTY TO SANTA FE PACIFIC MINING CO. DURING 1984-1985, SANTA FE COMPLETED GEOLOGIC MAPPING, A VLF SURVEY AND 16 DRILL HOLES TOTALING 9295 FT. SEVERAL OF THESE HOLES INTERSECTED NARROW ZONES OF GOLD MINERALIZATION, THE BEST BEING 45 FT./0.059 OPT GOLD. ALL MINERALIZED INTERCEPTS WERE AT THE CONTACT OF THE CHAINMAN SHALE AND JOANA LIMESTONE. SANTA FE TERMINATED THE LEASE IN 1985, THEN AAMINEX RETURNED CLAIMS BACK
  • TO TENNECO MINERALS CO. WHICH HAD SINCE ACQUIRED HIMCO. ALL DRILLING UP TO THIS TIME HAD BEEN COMPLETED IN THE VICINITY OF THE OUTCROPPING JASPEROIDS. IN 1986, TENNECO EXTENDED THE CLAIM BLOCK NORTH TO INCLUDE WHAT WOULD BECOME THE NIGHTHAWK RIDGE DEPOSIT. A SOIL GEOCHEMISTRY GRID IDENTIFIED TWO LINEAR GOLD ANOMALIES WHICH LED TO THE DISCOVERY OF OUTCROP OF FOLDED AND SILICIFIED CHAINMAN SHALE WITH ABUNDANT BARITE AND MINOR SCORODITE ALONG FRACTURES. 36 SAMPLES FROM THIS OUTCROP ASSAYED AS HIGH AS 2.33 PPM GOLD, BUT AVERAGED 0.5 PPM GOLD. HG,TL, AS, AND SB WERE ALSO ANOMALOUS. A 41 DRILL HOLE PROGRAM WAS INITIATED IN SEPTEMBER, 1986. THE DISCOVERY HOLE WAS THE 39TH HOLE, INTERSECTING 320 FT./0.066 OPT GOLD. ; ECON.COM: CASH COST OF PRODUCTION OF $240/OZ. GOLD.

Reference information

Bibliographic references

  • Deposit

    CARDEN, J.R., 1991, THE DISCOVERY AND GEOLOGY OF THE NIGHTHAWK RIDGE DEPOSIT AT EASY JUNIOR, WHITE PINE COUNTY, NEVADA, IN GEOLOGY AND ORE DEPOSITS OF THE GREAT BASIN, RAINES, G.L., ET AL, EDS., THE GEOLOGICAL SOCIETY OF NEVADA, RENO, P. 665-676.

  • Deposit

    NBMG, 1991, THE NEVADA MINERAL INDUSTRY 1990, NBMG SPECIAL PUBLICATION MI-1990, P.25.

General comments

Subject category Comment text
Deposit 75% OF ORE IS IN CHAINMAN SHALE, 25% IN JOANA LIMESTONE. ; INFO.SRC : 1 PUB LIT
Deposit REFER TO RECORD RE00028 FOR DATA ON THE ADJACENT DECKER FLATS DEPOSIT.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-DEC-1988 La Pointe, D.D. (Tingley, J.V.) Nevada Bureau of Mines and Geology
Updater 01-NOV-1991 Phinisey, J. D. (Marcus, S.) U.S. Geological Survey

Beyond USGS

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

Maps centered on this site

Authoritative Nevada resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.