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LJ Ridge Deposit

Producer in White Pine county in Nevada, United States with commodities Gold, Silver, Copper, Zinc, Arsenic, Antimony, Mercury, Bismuth, Tellurium
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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. Land status
  18. Ownership information
  19. Bibliographic references
  20. General comments
  21. Reporter information

Geologic information

Identification information

Deposit ID 10310447
Record type Site
Current site name LJ Ridge Deposit
Alternate or previous names Bald Mountain Mine Project
Related records 10045868, 10310370, 10310551

Comments on the site identification

  • This new record covers the LJ Ridge area of the Bald Mountain Mine project, which lies a mile east of the Pit 1-5 mine area.

Geographic coordinates

Geographic coordinates: -115.59589, 39.96659 (WGS84)
Elevation 2160
Relative position The mine area is located approximately 60 miles northwest of Ely, Nevada and 60 miles southeast of Elko, Nevada.

Site location context

Political divisions (FIPS codes)

White Pine(county)

Nevada(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Big Bald Mountain(quadrangle 1:24,000 scale)

Newark Lake(quadrangle 1:100,000 scale)

Ely(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

South Fork Humboldt(hydrologic unit)

Humboldt(hydrologic accounting unit)

Black Rock Desert-Humboldt(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 024N 057E 8 Nevada

Comments on the location information

  • The LJ Ridge mine area of the Bald Mountain Mine project lies on the west flank of Big Bald Mountain about a mile east of the Pit 1-5 mine area.

Commodities

Commodity Importance
Gold Primary
Silver Primary
Copper Tertiary
Zinc Critical Tertiary
Arsenic Critical Tertiary
Antimony Critical Tertiary
Mercury Tertiary
Bismuth Critical Tertiary
Tellurium Critical Tertiary

Comments on the commodity information

  • Ore Materials: gold
  • Gangue Materials: quartz, pyrite, arsenopyrite, sericite, and small amounts of sphalerite, chalcopyrite, tetrahedrite and galena.

Materials information

Materials Type of material
Gold Ore
Quartz Gangue
Pyrite Gangue
Arsenopyrite Gangue
Sericite Gangue
Sphalerite Gangue
Chalcopyrite Gangue
Tetrahedrite Gangue
Galena Gangue

Alteration

  • (Local) Alteration consists predominantly of silicification, argillization, and potassic alteration.

Mineral occurrence model information

Model code 75
USGS model code 19c
Deposit model name Distal disseminated Ag-Au
Mark3 model number 18

Host and associated rocks

  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Shale
    Rock type qualifier calcareous
    Rock unit name Dunderberg Shale
    Stratigraphic age (youngest) Late Cambrian
  • Host or associated Host
    Rock type Sedimentary Rock > Carbonate > Limestone
    Rock unit name Windfall Formation
    Stratigraphic age (youngest) Late Cambrian
  • Host or associated Associated
    Rock type Plutonic Rock > Granitoid > Quartz Monzonite
    Rock unit name Bald Mountain Stock
    Stratigraphic age (youngest) Late Jurassic
    Chronological age 159
  • Host or associated Associated
    Rock type Plutonic Rock > Porphyry > Lamprophyre
  • Host or associated Associated
    Rock type Plutonic Rock > Aplite

Nearby scientific data

(1) -115.59589, 39.96659
ListMap

Economic information

Geologic structures

Type of structure Regional
Structure description The Bald Mountain district is located in an area of thinned crust along the eastern side of the Late Proterozoic rift that split the North American craton. It is also in the west-central portion of the Late Devonian-Early Mississippian Antler foreland basin, and near the eastern edge of deformation related to the late Paleozoic Humboldt orogeny To the west of the Bald Mountain district, geologic interpretations are dominated by recognition of Paleozoic deformation, whereas to the east, interpretations emphasize Mesozoic contraction and plutonism and Tertiary extension.

Ore body information

  • General form tabular to irregular.

Controls for ore emplacement

  • Mineralization is structurally controlled. The dominant structural trend is N45W, but there are NE-, N-S, and E-W-trending structures as well. The E-W structures show the youngest period of movement, some of which is post-ore

Comments on the geologic information

  • Alteration comments: silicification, argillization, potassic alteration. The main alteration feature at Bald Mountain is the large halo of silicification and strong argillization. Potassic alteration is recognized at depth.
    Geology comments: Host rocks are calcareous shales and dark gray limestones which weather to iron-oxide stained red-brown-maroon and tan colors. Granitic intrusive with quartz phenocrysts and oxidized pyrite was noted in cut face of drill roads.
    Sulfur isotope studies indicate that ore fluids that formed the LJ Ridge deposit ere derived from the central part of the Bald Mountain stockigneous system.

Economic information about the deposit and operations

Operation type Surface
Development status Producer
Commodity type Metallic
Deposit size Medium
Significant Yes
Year of first production 1983
Year of last production 2000
Production years 1983; 1985 - 2000

Mining district

District name Bald Mountain District

Land status

Ownership category BLM Administrative Area
Area name Ely BLM district

Ownership information

  • Type Owner-Operator
    Owner Barrick Gold Corp.
    Year 2006

Comments on the workings information

  • Open pit mine

Comments on other economic factors

  • TIn 1996, the LJ Ridge orebody was reported to contain approximately 4 million tons of ore grading 0.1 opt gold.

Comments on development

  • Placer Dome began exploration on the Bald Mountain property in 1977. IN 1996, it was reported that the LJ Ridge deposit was the most recently discovered of the Bald Mountain district orebodies, after the No. 1-5, RBM, Rat, Top, Mahoney Canyon and Sage Flat deposits. Mining the LJ Ridge deposit was completed in 2000.
    In 2006, Barrick Gold Corp. acquired the LJ Ridge property through its acquisition of Placer Dome U. S., Inc.

Reference information

Bibliographic references

  • Deposit

    Hitchborn and others, 1996, Geology and Gold Deposits of the Bald Mountain Mining District, White Pine County, Nevada, in Geology and Ore Deposits of the American Cordillera Symposium Proceedings, eds. A. Coyner and P. Fahey.

  • Deposit

    The Geological Society of Nevada 1996 Spring Field trip, Geology and Gold Deposits of Eastern Nevada, GSN Special Publication No. 23.

  • Deposit

    Hose, Blake, and Smith, 1976, Geology and Mineral Resources of White Pine County, Nevada, NBMG Bulletin 85.

  • Deposit

    Hill, J. M., 1916, Notes on some Mining Districts in Eastern Nevada, USGS Bull. 648, p. 152-161.

  • Deposit

    Dean, D. A., Benedetto, K. M. F., Durgin, D. C., 1991, Part Two: Ely - Bald Mountain - Ely Road Log, in Buffa, R. and Coyner, A., eds., Geology and Ore Deposits of the Great Basin - Field Trip Guidebook Compendium, The Geological Society of Nevada, Reno, p. 136-162. 1981.

  • Deposit

    NBMG Map M84.

  • Deposit

    NBMG, 1994, MI-1993

  • Deposit

    Long, K.R., DeYoung, J.H., Jr., and Ludington, S.D., 1998, Database of significant deposits of gold, silver, copper, lead, and zinc in the United States; Part A, Database description and analysis; part B, Digital database: U.S. Geological Survey Open-File Report 98-206, 33 p., one 3.5 inch diskette.

  • Deposit

    Nutt, C.J., Hofstra, A.H., Hart, K.S., and Mortensen, J.K., 2000, Structural setting and genesis of gold deposits in the Bald Mountain-Alligator Ridge area, east-central Nevada, in Cluer, J.K., Price, J.G., Struhsacker, E.M., Hardyman, R.F., and Morris, C.L., eds., Geology and Ore Deposits 2000: The Great Basin and Beyond: Geological Society of Nevada Symposium Proceedings, May 15-18, 2000, p. 513-537.

  • Deposit

    BLM, 2004, Bald Mountain Mine Exploration Program Programmatic Environmental Assessment NV040-04-023, Case File # N78825.

General comments

Subject category Comment text
Deposit The LJ Ridge deposit is located about a mile east of the Pits 1-5 deposits and about two miles northwest of the Top deposit area. Ore at LJ Ridge is hosted mainly by a north-south-trending structure 6 to 15 meters wide and to a lesser degree by favorable stratigraphic horizons in the Dunderberg Shale.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-NOV-2004 LaPointe, D. D. Nevada Bureau of Mines and Geology
Editor 01-SEP-2007 Schruben, Paul G. U.S. Geological Survey Converted from S&A FileMaker format to Oracle. Edit checks on rocks, units, and ages with Geolex search, and other fields.

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.