Genesis-Blue Star Mines Area

Site Name

Primary: Genesis-Blue Star Mines Area
Secondary: North Star
Secondary: Genesis
Secondary: NW Genesis
Secondary: West #9
Secondary: Blue Star
Secondary: Deep Star
Secondary: Golden Zia
Secondary: Pay Raise
Secondary: Widge
Secondary: Beast
Secondary: Bobcat
Secondary: Blue Star Ridge
Secondary: Skarn Hill
Secondary: Sold

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Commodity

Primary: Gold
Secondary: Silver

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Location

State: Nevada
County: Eureka
District: Carlin Trend

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Land Status

Land ownership: BLM Administrative Area
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.
Administrative Organization: Elko Administrative District

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Holdings

Not available

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Workings

Not available

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Ownership

Owner Name: Newmont, the Gold Company
Info Year: 2004

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Production

Not available

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Deposit

Record Type: Site
Operation Category: Producer
Deposit Type: sediment-hosted gold-silver
Operation Type: Surface
Year First Production: 1961
Year Last Production: 2004
Discovery Year: 1985
Years of Production:
Organization:
Significant: Y
Deposit Size: L

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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, disseminated, and irregular

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Structure

Type: R
Description: Generally northwest-trending, broad to moderate amplitude, anticlinal folds play an important role as structural traps to fluid migration within individual deposits and on a regional scale. The autochthonous carbonate sequences that form the Carlin and Lynn tectonic windows are postulated to be remnant segments of a larger north-northwest-trending regional-scale anticline, with a doubly plunging fold axis that extends from the Gold Quarry deposit northward to the Genesis deposit. In this unified tectonic window model, gold deposits of the north-central and south-central Carlin trend are clustered along both the northeast and southwest flanks of the anticline, while its central portion has been segmented into a Tertiary, postmineral graben by late-phase Basin and Range extensional block faulting.

Type: L
Description: The K and Anne dikes are important dike-filled northeast fault structures in the Genesis Mine area.

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Alterations

Alteration Type: L
Alteration Text: Zonation patterns for silica-sulfide breccia pipes such as Deep Star exhibit compact envelopes in which silicification and sulfidation are more intensely focused than at other Carlin deposits.

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Rocks

Role: Associated
Age Type: Associated Rock Unit
Age in Years: 158.000000+-
Age Young: Late Jurassic

Name: Rhyolite
Role: Associated
Description: dike
Age Type: Associated Rock
Age in Years: 37.300000+-
Dating Method: K-Ar
Age Young: Middle Eocene

Role: Host
Age Type: Host Rock Unit
Age Young: Early Devonian
Age Old: Wenlock

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

Name: Carbonate
Role: Host
Description: thin-bedded silty micrite
Age Type: Host Rock
Age Young: Devonian

Name: Limestone
Role: Host
Description: thin-bedded silty
Age Type: Host Rock
Age Young: Devonian

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Analytical Data

Not available

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Materials

Ore: Gold
Ore: Clay
Gangue: Quartz

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Comments

Comment (Development): The earliest gold discovery in the Genesis-Blue Star area was at Blue Star, immediately south of Goldstrike, where gold was identified in 1957 in areas that had been mined for turquoise. In 1961, 800 ounces (25 kg) of gold was produced until problems with slimes in the ore led to shutdown of the 220-short-ton/day (200-t/d) cyanide mill. Trenching and drilling by Newmont in 1966 discovered low-grade gold in fault zones cutting a diorite intrusion (Goldstrike intrusion). Although this early exploration identified significant gold grades, further work was not conducted due to the low gold price. In 1984, Newmont Mining discovered the large Genesis deposit adjacent to the Blue Star deposit. The Blue Star-Genesis discovery was announced in 1985 and mining at Genesis began in 1986. Newmont began mining the North Star open pits in 1995. In 1996, open pit operations commenced production from the Beast pit. A current major exploration focus in 2004 is underground drilling along the Deep Post/Deep Star corridor, a mile-long drift connecting the two high-grade underground mines.

Comment (Commodity): Ore Materials: gold

Comment (Commodity): Gangue Materials: quartz, carbonaceous material, clay minerals

Comment (Geology): Age of the deposits: Drews (1993) reported three K/Ar dates ranging from 95 to 97 Ma from hydrothermal illite in high-grade (.0.20 opt gold) ore samples within the Genesis and Blue Star deposits. Post and Ressel and others, however, have constrained what appears to be the primary period of gold mineralization at the Beast deposit to late Eocene,~36-40 Ma. Multiple Tertiary-age intrusions along the Carlin trend and Tertiary-age dikes within specific deposits in the northern Carlin trend indicate the influence of a younger, gold-bearing hydrothermal event that occurred in the late Eocene, around 40 Ma. Henry and Ressel have reported 40Ar/39Ar dates from sericite ranging from 36 to 40 Ma on altered, gold-bearing dikes in the Post and Genesis fault zone. These dike swarms all occur within the Beast, Genesis, Griffin, and Meikle deposits in the northern Carlin trend. A single comparison of K/Ar and 40Ar/ 39Ar dates from the same altered dike in the Genesis deposit suggests that the potential effect of thermal resetting of K/Ar dates yields a younger age. Schutz and Williams (1995) reported a 27 Ma K/Ar date on the altered, gold-bearing K dike in the Genesis deposit; Henry and Ressel (2000) reported a 39 Ma 40Ar/39Ar date from the same altered dike.

Comment (Identification): This record encompasses deposits described individually by earlier records M242941, RE00284, M231429, RE00285, RE00283, W700376 and other nearby oreodies not described in MRDS records.

Comment (Location): The mine area is located about 4 miles northwest of the Carlin Mine, and a mle south of the southern margin fo the Betze-Post pit.

Comment (Workings): The mine area is developed by the Blue Star/Genesis Pit, the North Star Pit, the Sold Pit, the Beast Pit, and the Deep Star underground workings collared in the north part of the Blue Star/Genesis Pit.

Comment (Economic Factors): Approximate gold endowment at Genesis including satellite deposits was reported as 5.0 million ounces (156 t) of gold in 2002. This figure did not include the 1.6 million ounces (50 t) total endowment of gold attributable to the Deep Star deposit. Production at Deep Star began in January 1996 on the 5,050-foot level. The mine in 2002 produced about 600 tons (540 t) of ore per day. The mines in the Blue Star-Genesis area continue to produce at the present time (2004).

Comment (Deposit): These deposits are located in the part of the Carlin Trend that lies south of the Goldstrike stock between the Castle Reef and Gen Faults. The Popovich Formation hosts gold mineralization at Genesis-Blue Star where it consists of thin-bedded silty limestone and micrite.host rocks at Deep Star, Number 9, and part of the Genesis deposit have been metamorphosed to calc-silicate hornfels and minor skarn; the N10W Genesis fault and the N45 W Reindeer fault have been identified as the primary controls in the Genesis-Beast and the Northwest Genesis-North Star deposits, respectively. Deep Star is a compact, mineral replacement and breccia-hosted gold deposit

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References

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

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

Reference (Deposit): Nevada Mining Assn. Bull, Oct-Nov, 1985.

Reference (Deposit): NBMG Mining District File 115, numerous press clippings.

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): Chris H. Clode, Steven R. Grusing, Ivan M. Johnston, and Dean G. Heitt, 2002, Geology of the Deep Star Gold Deposit in NBMG Bull. 111

Reference (Deposit): Keith Bettles, 2002, Exploration and geology, 1962 to 2002, at the Goldstrike Property, Carlin Trend, Nevada; in NBMG Bull. 111.

Reference (Deposit): LONG AND OTHERS, 1998

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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.