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Tonkin Springs Gold Mine

Producer in Eureka county in Nevada, United States with commodities Gold, Silver, Arsenic, Mercury, Antimony, Zinc, 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. Land status
  18. Ownership information
  19. Production statistics
  20. Reserves and resources
  21. Links to other databases
  22. Bibliographic references
  23. General comments
  24. Reporter information

Geologic information

Identification information

Deposit ID 10310543
MRDS ID M242945
Record type Site
Current site name Tonkin Springs Gold Mine

Comments on the site identification

  • This record is an updated record including data from M242945 and W700599, which have been deleted. It also includes all material from earlier record W700407, which could be deleted.

Geographic coordinates

Point of reference Geographic coordinates: Elevation UTM Precision Relative position Point location
Pit -116.4525, 39.9076 (WGS84) The deposit is located about 65 km NW of Eureka, NV. This lat/long is for the pit 0.75 WNW of the mill.
(click for info)
Pit -116.4577, 39.9374 (WGS84) 100 Pit 2.5 miles NNW of mill.
Plant -116.4391, 39.9045 (WGS84) 100 Mill location.

Site location context

Political divisions (FIPS codes)

Eureka(county)

Nevada(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Tonkin Summit(quadrangle 1:24,000 scale)

Simpson Park Mountains(quadrangle 1:100,000 scale)

Millett(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Diamond-Monitor 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 Eureka

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 023.5 N 049E 03 Nevada
Mount Diablo 024 N 28 29 33 Nevada

Comments on the location information

  • The mine is located on the east flank of the Simpson Park Mountains.

Commodities

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

Comments on the commodity information

  • Ore Materials: pyrite, arsenopyrite, native gold,
  • Gangue Materials: realgar, orpiment, cinnabar, stibnite, quartz, calcite, barite

Materials information

Materials Type of material
Pyrite Ore
Arsenopyrite Ore
Gold Ore
Orpiment Ore
Cinnabar Ore
Stibnite Ore
Quartz Ore
Calcite Ore
Barite Ore
Realgar Gangue

Alteration

  • (Local) Alteration that has affected ore host rocks includes silicification, decalcification, argillization, carbonization. Silicification is widespread throughout the district and is evidenced by abundant jasperoid. Gold ore is often found in decalcified limestone. Argillization is widespread, but argillized rocks are generally not mineralized. The amount of carbonaceous ore has now been shown to be at least in part due to finely disseminated sulfide, not carbon.

Mineral occurrence model information

Model code 173
USGS model code 26a.1
Deposit model name Sediment-hosted Au
Mark3 model number 17

Host and associated rocks

  • Host or associated Host
    Rock type Sedimentary Rock > Carbonate > Limestone
    Rock unit name Vinini Formation
    Stratigraphic age (youngest) Ordovician
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Siltstone
    Rock unit name Devils Gate Limestone
    Stratigraphic age (youngest) Late Devonian
    Stratigraphic age (oldest) Middle Devonian
  • Host or associated Associated
    Rock type Plutonic Rock > Granitoid > Granodiorite
    Rock type qualifier sill
    Stratigraphic age (youngest) Early Oligocene
    Chronological age 33.4
    Stratigraphic age (youngest) Middle Eocene
    Chronological age 37.5
  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Rhyolite
    Rock type qualifier crystal-lithic tuff
  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Pyroclastic Rock > Tuff
    Rock type qualifier crystal-lithic rhyolite
  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Intermediate Volcanic Rock > Andesite
    Rock type qualifier porphyry
  • Host or associated Associated
    Rock type Plutonic Rock > Porphyry
    Rock type qualifier andesite
  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Dacite
    Rock type qualifier dikes

Nearby scientific data

Pit (1) -116.4525, 39.9076
ListMap
Pit (2) -116.4577, 39.9374
ListMap
Plant (3) -116.4391, 39.9045
ListMap

Economic information

Geologic structures

Type of structure Local
Structure description Intercalated slices of eastern and western facies rocks comprise the upper plate of the Roberts Mountains thrust. Brecciation and recumbent folding resulting from late Devonian to Mississippian deformation are well developed within the tectonically disturbed zone between slices. En echelon NNW-striking, east dipping normal faults of Tertiary age dominate the local structural fabric. ENE-striking, near vertical normal faults are subordinate in magnitude to the NNW trend and have localized silicification in places (e.g. Rooster Ridge). A N-S to NNE structural trend is recognized on high altitude photography.
Type of structure Regional
Structure description Roberts Mountains Thrust; WNW-striking broad, open folds.

Ore body information

  • General form TABULAR
    Thickness 33.53M
    Length 365.76M
    Width 182.88M
    Depth to top 0M

Controls for ore emplacement

  • The principal ore control is structure. All known orientations of high angle normal faults as well as lower angle thrust fault-related brecciation served as plumbing for the hydrothermal system. The NNW-striking set of normal faults defines the most noticeable trend of mineralization on the district level; higher grade pods usually flow this direction. The N60E set of normal faults is second in importance and serves to control mineralization at the individual pits. N-S control of mineralization is suggested by gold-in-soil anomalies and by subsurface gold mineralization in the Rooster main area.

Comments on the geologic information

  • Intrusive sills of intermediate composition are spatially associated with gold deposition. Since the sills are offset by feeder faults and can be mineralized, they are believed to pre-date gold deposition. The sills may have acted as impermeable caprocks to the hydrothermal system, resulting in the localization of gold in the sediments adjacent to the intrusive.

Economic information about the deposit and operations

Operation type Surface
Development status Producer
Commodity type Both
Deposit size Small
Significant Yes
Discovery year 1982
Discoverer Mineral Ventures Inc.
Mining method Open Pit
Year of first production 1985
Year of last production 1990
Plant type Leach
Milling method Leach-Solvent-Extract-Precipitation
Production years 1985-1990.

Mining district

District name Antelope District
District name Tonkin Springs District\n

Land status

Ownership category BLM Administrative Area
Area name Battle Mountain District

Ownership information

  • Type Owner-Operator
    Owner US Gold Corp.
    Year 2006
  • Type Owner-Operator
    Owner Gold Captial Corp.
    Interest 60
    Home office Colorado
    Year 1996
    First year 1993
  • Type Operator
    Owner Homestake Mining Co.
  • Type Owner
    Owner U.S. Gold Corp.
    Interest 40
    Home office Colorado
    Year 1996
    First year 1990
  • Type Owner
    Owner Homestake Mining Co./U. S. Gold JV

Production statistics

  • Year 1985
    Material ore processed
    Ore mined 253000mt
    Accuracy Accurate
    Description Ore Processed 253000 Metric Tons Ore/Year
  • Year 1986
    Material ore processed
    Ore mined 379000mt
    Accuracy Accurate
    Description Ore Processed 379000 Metric Tons Ore/Year
  • Year 1990
    Description Au 2735 Oz
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Primary metal recovered Gold Gold 85070g

Comments on the production information

  • 1988 PROD. = 50,000 OZ AND 1988 RESERVE = 345,071 OZ CONT.AU. (SUPPOSEDLY). 1989 BOM PROD. SURVEY SHOWS PROD. OF ONLY 1,753 OZ IN 1989 (SHUT DOWN?). QUESTION AS TO HOW MUCH RESERVE REMAINS. 1500 TO 2000 ST/DAY ORE, 1995.

Reserves and resources

  • Type In-situ
    Estimate year 1989
    Total resources 13000mt ore
    Commodity Subtype Grade units Group Importance Year
    Gold Au 1.741 g/mt Gold Major 1989
  • Type In-situ
    Estimate year 1996
    Demonstrated 3175000mt ore
    Commodity Subtype Grade units Group Importance Year
    Gold Au 3.43 g/mt Gold Major 1996
  • Type In-situ
    Estimate year 1996
    Demonstrated 8914000mt ore
    Commodity Subtype Grade units Group Importance Year
    Gold Au 1.96 g/mt Gold Major 1996
  • Type In-situ
    Estimate year 1983
    Commodity Subtype Grade units Group Importance Year
    Gold Au 27.99 g/mt Gold Major 1983
  • Type In-situ
    Estimate year 1987
    Commodity Subtype Grade units Group Importance Year
    Gold Au 15.551 g/mt Gold Major 1987
  • Type In-situ
    Estimate year 1987
    Commodity Subtype Grade units Group Importance Year
    Gold Au 2.79 g/mt Gold Major 1987

Comments on the reserve resource information

  • OPEN PIT; HEAP AND VAT LEACH OPERATION (INCL. BIOOXIDATION) OPERATION SHUTDOWN 1991; REPOENED 12/95; RESERVES 12/31/95.
  • 1991 RESERVES: OXIDE: 1.61 G/MT - 651,000 MT ORE SULFIDE: 1.21 G/MT - 636,000 MT ORE MILL: 2.58 G/MT - 2,523,000 MT ORE
  • RESOURCE INFORMATION IS FROM BATTLE MOUNTAIN GOLD COMPANY, 1986 ANNUAL REPORT.
  • http://www.romarco.com/news/index.php?&content_id=131
    26.5 million tonnes of measured and indicated resources grading 1.2 g/t as defined by Micon International Limited in their NI 43-101 report dated June 3, 2004 which was prepared for BacTech and can be found on www.sedar.com.

Comments on the workings information

  • TSP-1 pit, ore treatment facilities.
    In 1998 there was ongoing exploration, metallurgical testing, and mine development.

Comments on other economic factors

  • Reserves reported in 1987: 1.5 million tons of oxide ore grading 0.05 opt Au and 2.5 million tons of sulfide ore grading 0.09 opt Au. In 1996, reserves were reported as 9.8 million tons of ore grading 0.056 opt Au. In 1998 there were drill-defined reserves of 1.365 million ounces of Au.

    Production from 1987 through 1990 was 14,086 oz Au. Production of silver reported from 1989 through 1990 was 1870 oz Ag.
  • OPERATING COSTS IS $172/OZ AU EQUIVALENT.
  • STRIPPING RATIO IS REPORTED AT 16:1, AND SHOULD REDUCE TO 5:1.

Comments on development

  • Exploration began in the Tonkin Springs area during the 1950s and 1960s. The Rooster claims were staked in 1966 by Lyle Campbell on the basis of outcropping jasperoid. Claims optioned by several companies 1966-81, with additional staking expanding the claim block during this period. Companies which conducted exploration during that time, included Homestake Mining, American Selco, Chevron Resources, Placer Amex, Earth Resources and Freeport Exploration. These companies discovered gold mineralization but considered to be too low-grade and sporadic at that time to be of interest . Mineral Ventures, Inc. conducted a drainage sediment sampling program in 1979. Anomalous gold concentrations were identified on the Rooster claims and for several miles to the south. Drainages in the immediate vicinity of the Tonkin Springs deposit contained gold contents varying between 0.03 and 0.06 ppm. The Rob claims were then staked in 1980. Precambrian Exploration teamed with Mineral Ventures, Inc. in 1982 to explore the Rob Claims. Geologic mapping and grid soil and rock geochemical surveys defined the drill targets that became the TSP 1,3, and 4 orebodies. These shallow ore pods had coincident Au, Hg, As, and Sb soil anomalies (see Mehrtens, 1987). Silver State Mining (now U.S. Gold) optioned the property in January 1985 and put the property into production. The first gold was poured October 1985. The land position was expanded by the optioning of the Rooster claims in 1986 and claim staking in the Twin Peaks area in 1987. The claim block in 1990 encompasses approximately 42 square miles along trend. A joint venture of U.S. Gold (49%) and Homestake Mining (51%) was formed in early 1991 to further explore and develop Tonkin Springs. According to Silver State Mining 1985 annual report, total capital costs are $1.90 million, production costs are $85/oz. Au ($122/oz. Au, including depreciation, depletion, and amortization), and gold recovery rate is 70%. U.S. Gold is pioneering bio-oxidation of bulk gold ores at Tonkin Springs.
    From 1981 to 1985, Energy Reserves Group and Mineral Ventures continued to explore the property until their mining leases were terminated. In January, 1986 US Gold Corporation leased the property and has controlled it ever since.

    Exploration in the area that hosts the sulfide deposits began in 1979. At this time, Mineral Ventures conducted sampling program searching for Carlin-type gold deposits. In 1981, Mineral Ventures conducted a drilling program that encountered potentially economic mineralization at what later became known as the TSP-1 deposit. The company continued exploration drilling and, in 1985, US Gold entered into a joint venture on the property with Mineral Ventures. In 1987, US Gold bought control of the company.

    The drilling completed by US Gold from the mid to late 1980s delineated several more small deposits. Mining activities took place that produced over 30,000 ounces of gold, mostly from oxide ores. During the work, many roads were constructed and heap leach pad was built and operated. From 1998 to 1990, in excess of $30 million was spent constructing an on site mill. Many more claims were added to the property position and several exploration targets were found.

    From 1991 to 2001, US Gold teamed up with several mining companies to explore the property. Some of the companies included Homestake Mining, Gold Capital, Globex Mining and Agnico-Eagle. Each of these companies conducted an exploration program which laid out different goals.

    Homestake drilled 86 reverse circulation and core holes. Though several interesting showings were encountered in this drilling, Homestake determined it had not discovered a deposit that met its corporate objectives and, in 1992, it withdrew from the joint venture.
  • In 1993, Gold Capital attempted to modify the existing heap leach pad but ran short of financial resources. In February, 1999 it sold its interest to Agnico-Eagle. From 1993 to 1999, little exploration took place on the property.

    Agnico-Eagle drilled 107 reverse circulation holes and confirmed the mineral resource at Tonkin Springs. It also extended the known mineralization at various deposits on the property and discovered new gold mineralized zone at the north end of the property. Aginco-Eagle did not find enough economic mineralization to justify its goals and, in October, 2001, also withdrew from the joint venture.

    In 2003, BacTech acquired a 55% interest in the property from US Gold. However, BacTech was unable to fulfill the requirements set out in the agreement, giving US Gold 100% ownership over Tonkin Springs.

    In July 2005, Rob McEwen purchased 33% of US Gold and also assumed the position of Chairman and CEO.
  • http://www.romarco.com/news/index.php?&content_id=131
    The Tonkin Springs Mine is a previously producing gold mine strategically located in the prolific Cortez Gold Trend of Nevada. The property package encompasses 36 square miles and has existing infrastructure including a 1,800 tonne-per-day mill on site. It is anticipated that a feasibility study will be conducted immediately for start up operations.
    Strategically located on the Cortez Gold Trend south of the Placer Dome:Rio Tinto Cortez Joint Venture's Pipeline deposit and the recently discovered Cortez Hills deposit
    In operation from 1985 to 1988 and again in 1990
    Existing mill and infrastructure (+$30 million original cost)
    36 square mile land package provides exploration potential

Reference information

Bibliographic references

  • Deposit

    Nevada Division of Mine Inspection Staff, 1988, Directory of Nevada mine operations active during calendar year 1987: 84 p.

  • Deposit

    Benedetto, K., et al, 1992, Roadside Geology and Precious Metal Mineralization along U.S. 50, Reno To Ely, Nevada, 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. 1133.

  • Deposit

    Eespell, R. and Rich, T., 1992, Geology and Mineralization of the Tonkin Springs Mining District, in Buffa, R. and Coyner, A., Geology and Ore Deposits of the Great Basin - Field Trip Guidebook Compendium, The Geological Society of Nevada, Reno, p. 949-958.

  • Deposit

    Tingley and Smith, 1983, A Mineral Inventory of The Shoshone-Eureka Resource Area, Battle Mountain, Nevada: NBNG Open File Report 83-3.

  • Deposit

    Tingley and Smith, 1983, Results of geochemical sampling within the Shoshone-Eureka Resource Area, Eureka, Lander, and Nye Counties, Nevada: NBMG Open File Report 83-4.

  • Deposit

    Bonham, H., 1989, Bulk-Mineable Precious-Metal Deposits and Prospects in Nevada: NBMG Map 91.

  • Deposit

    NBMG, 1988, The Nevada Mineral Industry - 1987, NBMG Special Publication MI-1987.

  • Deposit

    NBMG, 1991, The Nevada Mineral Industry - 1990, NBMG Special Publication MI-1990.

  • Deposit

    USGS Open-File Report 376, 1978.

  • Deposit

    Hardesty, R., 1983, The Tonkin Springs Gold Deposit, presentation at the 89th Annual Northwest Mining Association Convention, Spokane; copy in NBMG Mining District File #106.

  • Deposit

    Mehrens, M.B., 1987, Case history and problem 1: The Tonkin Springs Gold Mining District, Nevada, U.S.A., in Fletcher, W.K., et al., eds., Exploration geochemistry: design and interpretation of soil surveys, Reviews in Economic Geology, vol. 3, p. 129-134.

  • Deposit

    Silver State Mining 1985 Annual Report.

  • Deposit

    NBMG Mining District File #106, Press Clippings.

  • Deposit

    NBMG, 1994, MI-1993, MI-96; MI-97; MI-98; NBMG Map 91, 1st, 2nd, 3rd; Amer. Mines (1998) 1997: Mas, 1984; Amer. Mines (1999), 1998.

  • 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

    US Gold Corp website 2006

  • Reserve-Resource

    1995/96, NEVADA MINES DIRECTORY, PP. 18, 19, 24.

  • Reserve-Resource

    GOLD CAPITAL CORPORATION, 1995, FORM 10-KSB, P9.

  • Deposit

    NEVADA MINING ASSOCIATION BULLETIN, ENERGY RESERVES GROUP FINDS GOLD MINERALIZATION IN EUREKA CO., OCT-NOV, 1981, VOL 3, # 6, P16.

  • Deposit

    RANDOL, 1996/97, MININING DIRECTORY, U.S. MINES & MINING COMPANIES, P275.

  • Deposit

    THE MINING RECORD, VOL 107, #?, AUG. 31, 1996, P9.

  • Deposit

    THE MINING RECORD, VOL 107, #41, OCT. 9, 1996, P1.

  • Deposit

    THE MINING RECORD, VOL 108, #16, APR. 16, 1997, P3.

  • Deposit

    U.S. GOLD COPR., NEWS RELEASE, APR., 29, 1996.

General comments

Subject category Comment text
Deposit Approximately 75% of gold occurs as micron-sized grains in pyrite and arsenopyrite. 25% of gold occurs as free grains in silica veinlets or along fractures.
Environmental Factors THE TAILINGS DAM, WASTE DUMP, AND EXISTING HEAP LEACH ARE BUILT ON A THICK ZONE OF ALTERED CLAY VOLCANICS WITH VERY LOW PERMEABILITIES (10E-8 CM/SEC).
Environmental Factors MINOR AMOUNTS (0.25%) PYRITE IN WASTE MATERIAL. SMALL AMOUNTS (0.25-0.5%) PYRITE IN TAILS.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-AUG-88 Paidakovich, Matthew E. U.S. Geological Survey
Updater 01-SEP-88 La Pointe, D.D. (Tingley, J.V.) Nevada Bureau of Mines and Geology
Updater 01-AUG-89 Beougher, Dee (Spanski, Gregory T.) U.S. Geological Survey
Updater 01-FEB-92 Phinisey, J. D. (Marcus, S.) U.S. Geological Survey
Updater 01-SEP-94 Li, Zhiping (Moyer, Lorre A.) U.S. Geological Survey
Reporter 04-AUG-97 Buckingham, David A. U.S. Bureau of Mines
Reporter 01-DEC-06 La Pointe, D.D. Nevada Bureau of Mines and Geology
Editor 01-SEP-07 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.

Operator history (post-MRDS)

MRDS records operators as of each record's last update (≤ 2019). Some of the operators listed here have since changed hands or dissolved:

  • Homestake Mining Co. — acquired by Subsidiary of Barrick Gold (2001)
    Operator of the historic Homestake Mine in South Dakota; acquired by Barrick Gold in 2001.

Curated by qvyshift.com from publicly-reported M&A activity (SEC filings, press releases, USGS Mineral Yearbooks). Not authoritative — verify against primary sources before relying on it. The MSHA panel above is the current authoritative source for actively-permitted mines.

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.