Tusc Deposit

The Tusc Deposit is a gold and silver mine located in Eureka county, Nevada at an elevation of 5,610 feet.

About the MRDS Data:

All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.

Mine Info

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Site Name

Primary: Tusc Deposit
Secondary: part of Newmont?s Carlin-South operations
Secondary: MAC Deposit

Commodity

Primary: Gold
Primary: Silver
Tertiary: Arsenic
Tertiary: Antimony
Tertiary: Barium-Barite
Tertiary: Mercury
Tertiary: Copper
Tertiary: Lead
Tertiary: Zinc

Location

State: Nevada
County: Eureka
District: Carlin Trend

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.

Holdings

Not available

Workings

Type: Surface

Ownership

Owner Name: Newmont Gold Corp.
Info Year: 2004

Production

Not available

Deposit

Record Type: Site
Operation Category: Producer
Deposit Type: disseminated
Plant Type: Leach
Operation Type: Surface
Mining Method: Open Pit
Milling Method: Carbon-In-Leach-Electrowin
Year First Production: 1994
Year Last Production: 2004
Discovery Year: 1985
Years of Production:
Organization:
Significant: Y
Deposit Size: M

Physiography

Not available

Mineral Deposit Model

Model Name: Sediment-hosted Au

Orebody

Form: tabular

Not available

Structure

Type: L
Description: The Good Hope fault system which strikes N40W and dips steeply SW is a narrow reverse fault that strikes N45W and has highly variable dip. It connects Tusc to Gold Quarry. At Tusc, it juxtaposes Roberts Mountains Formation and the Rodeo Creek Unit.

Type: R
Description: Anticlinal folding has warped host rocks in the mine area

Alterations

Alteration Type: L
Alteration Text: Argillization, decalcification, silicification, and baritization are the dominant forms of alteration. Most of Tusc is weakly to moderately argillized. Intense argillization occurs in some fault zones. Decalcification is strong to moderate. Along most faults, silicification is intense and jasperoids are common. Baritization is of minor importance, occurring as thin discontinuous veins associated with areas of intense silicification.

Rocks

Name: Argillite
Role: Host
Description: siliceous
Age Type: Host Rock
Age Young: Devonian

Name: Chert
Role: Host
Description: argillaceous
Age Type: Host Rock
Age Young: Devonian

Name: Siltstone
Role: Host
Description: calcareous
Age Type: Host Rock
Age Young: Devonian

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

Name: Limestone
Role: Host
Description: sandy
Age Type: Host Rock
Age Young: Early Devonian
Age Old: Wenlock

Analytical Data

Analytical Data: A strong geochemical halo surrounds the Tusc orebody. This is defined mainly by elevated concentrations of as (500 to 3000 ppm) and Sb (50-200 ppm). Locally, Ag, base metals, and Hg are weakly to moderately anomalous.

Materials

Ore: Gold
Ore: Realgar
Ore: Pyrite
Ore: Galena
Ore: Cinnabar
Ore: Arsenopyrite
Ore: Stibnite
Gangue: Hematite
Gangue: Barite
Gangue: Calcite
Gangue: Illite
Gangue: Sericite
Gangue: Alunite
Gangue: Quartz
Gangue: Kaolinite

Comments

Comment (Commodity): Ore Materials: gold

Comment (Deposit): Submicroscopic, epithermal gold mineralization is disseminated along fractures and pores in the Roberts Mountains Formation and the Rodeo Creek Unit. The Tusc orebody has a synformal character which plunges to the northwest.

Comment (Commodity): Gangue Materials: kaolinite, alunite, sericite (or illite), barite, hematite.

Comment (Development): Tusc was discovered in 1985 by Newmont geologists during a reconnaissance exploration program focused on geochemical and geological targets to the northwest of Gold Quarry. The deposit was in the advanced exploration/mine design stage in 1992, and production began in 1994.

Comment (Economic Factors): In 1988 Tusc was reported to have a geologic resource of 15.8 million tons of ore grading 0.059 ounces of gold per ton. In 1990 Tusc was reported to have reserves of 13.3 million tons of ore grading 0.062 ounces of gold per ton. Tusc?s production was lumped together with that of Gold Quarry and MAC deposits, and not published individually.

Comment (Identification): This record is an update of record # RE00036 from which all pertinent information has been extracted.

Comment (Location): The Tusc Deposit is located 1.5 miles NW of the Gold Quarry Mine

References

Reference (Deposit): NBMG, 1994, MI-1993

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): John W. Norby and Michael J.T. Orobona, 2002, Geology and Mineral Systems of the Mike Deposit; in Gold Deposits of the Carlin Trend, NBMG Bull. 111.

Reference (Deposit): Schull, H.W., 1991, The Lithostratigraphy and Sedimentology of the Contact/Transition Between the Roberts Mountains Formation and the Western Facies Rocks in the Carlin Mining District, Eureka and Elko Counties, Nevada, in Raines, G.L., et al., eds., The Geology and Ore Deposits of the Great Basin, The Geological Society of Nevada, Reno, p. 705-712.

Reference (Deposit): Ekburg, C., Rota, J., and Arkell, B., 1991, Geology and Mineral Deposits of the Maggie Creek Subdistrict, Carlin Trend, Eureka County, Nevada, in Raines, G.L., et al., eds., The Geology and Ore Deposits of the Great Basin, The Geological Society of Nevada, Reno, p. 625-633.

Reference (Deposit): Rota, J., 1990, Geology and Mineral Deposits of the Maggie Creek Subdistrict, Carlin Trend, Eureka County, Nevada, Oral Presentation at Great Basin Symposium, The Geological Society of Nevada, Sparks, NV, April, 1990.

Reference (Deposit): Arkell, B., 1992, Geology of the Tusc and Mac Deposits, 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. 862-864.

Reference (Deposit): Mcfarlane, D., 1992, Gold Production on the Carlin Trend, 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. 841-843.

Reference (Deposit): U.S. BUR. LAND MANAGEMENT. NEWMONT GOLD COMPANY'S SOUTH OPERATIONS AREA PROJECT. DRAFT EIS, MAY 1993.

Reference (Deposit): EKBURG, C. E., ROTA, J. C., AND B. W. ARKELL. GEOLOGY AND MINERAL DEPOSITS OF THE MAGGIE CREEK SUBDISTRICT, CARLIN TREND, EUREKA COUNTY, NEVADA: IN GEOLOGY AND ORE DEPOSITS OF THE GREAT BASIN PUBLISHED BY THE GEOLOGICAL SOCIETY OF NEVADA, 1991, PP. 625-633.

Reference (Deposit): MINING JOURNAL, V308, # 7915, MAY 1, 1987, P332, INDUSTRY IN ACTION", "MORE GOLD FOR NEWMONT...".

Reference (Deposit): WINTERS, R. A. MINES AND ORE BODIES IN THE CARLIN TREND, NEVADA--AN OVERVIEW OF THEIR EXPLORATION, DEVELOPMENT, PAST, PRESENT, AND FUTURE PRODUCTION, AND IMPORTANCE TO THE NEVADA ECONOMY: UNPUBLISHED REPORT TO THE ELKO DISTRICT, BUREAU OF LAND MANAGEMENT, ON FILE AT THE BUREAU OF MINES, WESTERN FIELD OPERATIONS CENTER, SPOKANE, WA.

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.