Horse Canyon Mine

Site Name

Primary: Horse Canyon Mine
Secondary: Cortez Joint Venture
Secondary: Horse Canyon pit
Secondary: South Silicified pit

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Commodity

Primary: Gold
Secondary: Silver
Tertiary: Barium-Barite

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Location

State: Nevada
County: Eureka
District: Cortez District

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Land Status

Land ownership: Private
Note: the land ownership field only identifies whether the area the mine is in is generally on public lands like Forest Service or BLM land, or if it is in an area that is generally private property. It does not definitively identify property status, nor does it indicate claim status or whether an area is open to prospecting. Always respect private property.

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Holdings

Not available

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Workings

Not available

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Ownership

Owner Name: Cortez Joint Venture: Kennecott Explorations
Info Year: 2004

Owner Name: Cortez Joint Venture: Placer Dome, Inc.
Info Year: 2004

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Production

Not available

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Deposit

Record Type: Site
Operation Category: Past Producer
Deposit Type: disseminated/thrust fault
Operation Type: Surface
Year First Production: 1983
Year Last Production: 1993
Discovery Year: 1976
Years of Production:
Organization:
Significant: Y
Deposit Size: S

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Physiography

Not available

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Mineral Deposit Model

Model Name: Sediment-hosted Au

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Orebody

Form: tabular to irregular

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Structure

Type: R
Description: Roberts Mountains Thrust; Cortez Window

Type: L
Description: high angle faulting; fractures; folding

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Alterations

Alteration Type: L
Alteration Text: silicification, bleaching, clay alteration

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Rocks

Name: Rhyolite
Role: Associated
Description: small rhyolite intrusives less than 1 mile away.
Age Type: Associated Rock
Age Young: Tertiary

Role: Host
Age Type: Host Rock Unit
Age Young: Devonian

Name: Shale
Role: Host
Description: cherty
Age Type: Host Rock
Age Young: Ordovician

Name: Shale
Role: Host
Description: siliceous
Age Type: Host Rock
Age Young: Ordovician

Name: Shale
Role: Host
Description: carbonaceous
Age Type: Host Rock
Age Young: Ordovician

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Analytical Data

Not available

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Materials

Ore: Gold
Ore: Barite
Gangue: Pyrite
Gangue: Quartz
Gangue: Clay
Gangue: Jarosite

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Comments

Comment (Geology): The deposit area was visited by NBMG geologists in 1982 before it was mined. Along the southeast drill roads, the most conspicuous feature was a Vinini-hosted jasperoid breccia forming a resistant NW-striking rib above the drill roads. Jasperoid is highly silicified, fractured, and iron stained along the fractures. Bedding is preserved in the jasperoid in places and dips southeast. Below the jasperoid breccia are thin contorted beds of black carbonaceous shales. In one area the southeast -dipping shales are cut by an altered igneous dike, mostly altered to clays. The surrounding shales have been bleached. A sample was taken here, of black siliceous shale and cherty shale drill cuttings. To the northwest in probable future pit area, the resistant rib of Vinini jasperoid breccia is still present. Below the breccia are thin bedded siliceous sediments. A large boulder of breccia found on the road was cut by a small breccia vein containing a clast of quartz-eye porphyry. However, the most notable occurrence was of abundant euhedral jarosite crystals developed in the open fractures of the jasperoid (sampled). Some barite vein and gangue was also noted in this area. Another sample consists of drill cuttings of dark gray calcareous shales with fine disseminated sulfides.

Comment (Identification): This record supersedes the earlier record M242255 and includes all material in the earlier record.

Comment (Location): UTM is to large open pit area at head of Horse Canyon on east flank of Mount Tenabo near saddle between Horse Canyon and Mill Canyon.

Comment (Workings): The Horse Canyon mine area encompasses the Horse Canyon and South Silicified open pit mines.

Comment (Development): The Horse Canyon deposit was discovered about 1982 and open pit gold mining commenced in 1983, employing 106 workers. Annual recovery of 40,000 ounces of gold was projected. The mine produced until 1985 and again 1988-1993. With the upswing in gold prices, Cortez Gold Mines began re-exploring near the old Horse Canyon Mine area and in late November 2002, five drill rigs were mobilized in the area. With the 2002 discovery of the Pediment and Cortez Hills deposits, CJV continued exploration in what they call the Horse Canyon/ Cortez Unified Exploration Program for which and Environmental Assessment was filed in Sept., 2004. The EA described a proposed Phase I Exploration Program that would involve widespread exploration drilling to advance/test target areas. It will include approximately 150 drill sites followed by follow-up drilling of another 100-200 drill sites.

Comment (Economic Factors): Reserves in 1984 were reported at 3.94 million tons or ore grading 0.055 ounces of gold per ton. The mine was in production from 1983 to 1985, and again from 1988 through 1993. 1984 production from Horse Canyon Mine was 40,000 ounces of gold. 1988-93 production was included with that of Gold Acres.

Comment (Commodity): Ore Materials: gold, barite, sulfides

Comment (Commodity): Gangue Materials: quartz, clay, jarosite, iron oxides, pyrite

Comment (Deposit): Fine-grained gold is disseminated in carbonaceous shale in the upper plate of the Roberts Mountain thrust. Ore is localized by the Roberts Mountains Thrust plate contact and by north-striking high angle structures. Ore zone is characterized by jasperoid breccia. The surface expression of the deposit was a bouldery resistant rib of jasperoid trending northwest along most of area covered by drill roads prior to mining. .

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References

Reference (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.

Reference (Deposit): BLM, Sept., 2004, Horse Canyon/Cortez Unified Exploration Project II Environmental Assessment NV063-EA04-61.

Reference (Deposit): NBMG MI-82 through MI-84; MI-86 thru MI-02;

Reference (Deposit): NBMG Map 91, 1st, 2nd, 3rd;

Reference (Deposit): NBMG OFR 83-9;

Reference (Deposit): Bentz, J., Bonham, H., Tingley, J.V., Smith, P., 1982, Field Examination Report, 7/82.

Reference (Deposit): Unpublished report by Cortez Gold Mines, 1983

Reference (Deposit): MASMILS 0320110228;

Reference (Deposit): Crescent Valley Land Status, 1979;

Reference (Deposit): Amer. Mines (1989), 1989;

Reference (Deposit): NBMG Mining District File 109, Numerous Clippings. 332

Reference (Deposit): McCormack, John K., 1991, written communication

Reference (Deposit): Amer. Mines (1990), 1990;

Reference (Deposit): Amer. Mines (1991-92), 1991;

Reference (Deposit): EA, 2000;

Reference (Deposit): Adella Harding, Elko Daily Free Press, 11/23/02.

Reference (Deposit): www.placerdome.com

Reference (Deposit): Bonham, H.F., 1988, in NBMG MI-1987.

Reference (Deposit): Bonham, H.F., 1986, NBMG Map 91.

Reference (Deposit): Foo, S.T., and Hebert, J. P., 1987, Geology of the Horse Canyon Deposit, Eureka County, Nevada, in Johnson, J. L., ed., Guidebook for Field Trips, Bulk Mineable Precious Metal Deposits of the Western United States, Geological Society of Nevada Symposium, April 6-8, 1988, Reno, Nevada. p. 326.

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Nevada Gold

Nevada has a total of 368 distinct gold districts. Of the of those, just 36 are major producers with production and/or reserves of over 1,000,000 ounces, 49 have production and/or reserves of over 100,000 ounces, with the rest having less than 100,000 ounces. Read more: Gold Districts of Nevada.