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Buffalo Valley Gold Mine

Producer in Lander county in Nevada, United States with commodities Gold, Silver, Copper, Arsenic, Nickel
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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 10310306
MRDS ID M231308
Record type Site
Current site name Buffalo Valley Gold Mine
Alternate or previous names Buffalo Valley Mine, A/B/O Complex, Dore Hills, North Margin Zone
Related records 10106923, 10149446

Comments on the site identification

  • This is a new record incorporating all material from earlier record # M231308 as well as additional information. Do not confuse this deposit with the Buffalo Valley molybdenum prospect that lies 7 km to the south at the SW tip of Battle Mountain in secs. 21 and 28, T31N, R42E (no MRDS record). This record has been merged with data from record #m233793, which has been deleted.

Geographic coordinates

Geographic coordinates: -117.24789, 40.60379 (WGS84)
Elevation 1760
Relative position The Buffalo Valley Mine is located 16 miles south of the Valmy exit on Interstate 80 and 17 miles WSW of the town of Battle Mountain, Nevada.

Site location context

Political divisions (FIPS codes)

Lander(county)

Nevada(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Antler Peak(quadrangle 1:24,000 scale)

Winnemucca(quadrangle 1:100,000 scale)

Winnemucca(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Dixie Valley(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 Lander

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 032N 042E 28 33 34 Nevada

Comments on the location information

  • The Buffalo Valley Mine is located between Timber and Mill Canyons. UTM is to shafts of historic underground workings at the north end of the current open pit.

Commodities

Commodity Importance
Gold Primary
Silver Primary
Copper Secondary
Arsenic Critical Tertiary
Nickel Critical Tertiary

Comments on the commodity information

  • Ore Materials: auriferous pyrite, native gold, chalcopyrite, malachite, chrysocolla
  • Gangue Materials: limonite, hematite, quartz, biotite, diopside, clinozoisite, epidote

Materials information

Materials Type of material
Pyrite Ore
Gold Ore
Chalcopyrite Ore
Malachite Ore
Chrysocolla Ore
Limonite Gangue
Hematite Gangue
Quartz Gangue
Biotite Gangue
Diopside Gangue
Clinozoisite Gangue
Epidote Gangue

Alteration

  • (Local) Contact metamorphic effects in the upper structural unit of the Havallah Sequence: non-calcareous silty lithologies are converted to biotite hornfels; slightly calcareous, siliceous and argillaceous siltstones are metamorphosed to calc-silicate hornfelses (diopside + quartz plagioclase, clinozoisite, epidote). Sulfides are restricted to later fractures. Endoskarn: sulfide-poor calc-silicate mineral assemblages which occur as alteration products of porphyry dikes are common west and southwest of the open pit, rare in the open pit, and absent east and north of the pit. In some hand specimens, endoskarn alteration can be observed as envelopes about individual quartz veins, e.g. plagioclase-quartz-pyroxene-bearing inner envelopes (hornblende destroyed) and relict hornblende-stable outer envelopes. Potassic alteration: shreddy hydothermal biotite is abundant in dikes in the open pit and the degree of biotization is independent of proximity to quartz veins. Prograde skarn: a few unequivocal but rare examples of coarse grained garnet-pyroxene skarn have been exposed in the center of the open pit, interbedded with calc-silicate hornfels. These skarns contain pyrite, although it is unclear whether it was deposited synchronous with skarn silicates. Retrograde skarn: pyroxene hornfels and less commonly basalt and biotite hornfels locally are intensely altered to dark green chlorite, pyrite, and nontronite(?). This assemblage has been reported to carry free gold.

Mineral occurrence model information

Model code 64
USGS model code 18f
Deposit model name Skarn Au
Mark3 model number 82

Host and associated rocks

  • Host or associated Host
    Rock type Sedimentary Rock > Chemical Sediment > Chert
    Rock unit name Havallah Formation
    Stratigraphic age (youngest) Early Permian
    Stratigraphic age (oldest) Middle Pennsylvanian
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Argillite
    Rock unit name Havallah Formation
    Stratigraphic age (youngest) Early Permian
    Stratigraphic age (oldest) Middle Pennsylvanian
  • Host or associated Host
    Rock type Sedimentary Rock > Carbonate > Limestone
    Rock unit name Havallah Formation
    Stratigraphic age (youngest) Early Permian
    Stratigraphic age (oldest) Middle Pennsylvanian
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Siltstone
    Rock unit name Havallah Formation
    Stratigraphic age (youngest) Early Permian
    Stratigraphic age (oldest) Middle Pennsylvanian
  • Host or associated Host
    Rock type Metamorphic Rock > Metasedimentary Rock > Quartzite
    Rock unit name Havallah Formation
    Stratigraphic age (youngest) Early Permian
    Stratigraphic age (oldest) Middle Pennsylvanian
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Shale
    Rock unit name Havallah Formation
    Stratigraphic age (youngest) Early Permian
    Stratigraphic age (oldest) Middle Pennsylvanian
  • Host or associated Associated
    Rock type Plutonic Rock > Granitoid > Granodiorite
    Stratigraphic age (youngest) Eocene
  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Pyroclastic Rock > Tuff > Ash-Flow Tuff
    Stratigraphic age (youngest) Eocene
  • Host or associated Associated
    Rock type Unconsolidated Deposit > Alluvium
    Stratigraphic age (youngest) Tertiary

Nearby scientific data

(1) -117.24789, 40.60379
ListMap

Economic information

Geologic structures

Type of structure Local
Structure description The Havallah Sequence of the Buffalo Valley Mine has a homoclinal appearance. With certain exceptions, beds strike NW to slightly east of north and generally dip 45-65 SW or West. Buffalo Valley Mine is situated in a fault block that is bounded on the east by the western range-bounding fault of Battle Mountain and on the west by another west-dipping normal fault, which is known locally as the Front Fault.
Type of structure Regional
Structure description Golconda Thrust

Ore body information

  • General form tabular

Controls for ore emplacement

  • Larger orebodies mined underground during 1924-1951 formed in calcareous beds between strands of the Front fault; smaller orebodies were formed in calcareous beds near shear zones and small faults in the footwall of the Front fault. Oxidized, sheeted pyrite veinlets that generally parallel the axis of the open pit host a majority of the gold mined in the open pit. This veinlet zone is located in the NE part of a contact metamorphic aureole and is centered directly on a swarm of porphyry dikes. Auriferous sulfide veinlets, quartz veinlets, and dikes all have similar attitudes.

Comments on the geologic information

  • Rocks of the Havallah Sequence in the Buffalo Valley Mine area can be grouped into 3 local units (and their metamorphic and metasomatic equivalents): 1) a lower structural unit consisting of chert, lesser shale and siltstone, minor pebbly sandstone rich in black chert clasts, and minor limestone; 2) a sill or lava flow of fine grained basalt; and 3) an upper structural unit consisting of non-calcareous to weakly calcareous siltstone, quartzite, and shale. The basalt and upper structural unit are exposed in the pit. Variably altered granodioritic porphyry dikes intrude the Havallah Sequence rocks throughout the mine area and are interpreted to be part of a late Eocene(?) porphyry system, inferred to be related to a larger subjacent pluton. Some dikes carry anomalous gold values, indicating that gold deposition post-dates intrusion of the dikes. Unaltered, unmineralized intercalated ash flow tuffs and alluvium overlie the Havallah Sequence rocks and dikes. Based on the spatial correspondence of au-bearing pyritic veins with the swarm of dikes in the pit and the presence of minor au occurrences associated with outlying porphyry dikes, Seedorff (1991) suggests that gold deposition is related to the Copper Canyon porphyry system. Roberts and Arnold (1965) report the presence of a vein containing pyrite and chalcopyrite 800 feet SE of the historic workings which assays up to 2.0 oz/ton gold. This is likely in the area which has been developed as an open pit. According to shipment records from 1924-1951, the gold and silver content of the ore increases with an increase in copper.

Economic information about the deposit and operations

Operation type Surface-Underground
Development status Producer
Commodity type Metallic
Deposit size Small
Significant Yes
Discovery year 1916
Discoverer C. Ganser and others
Year of first production 1924
Year of last production 1990
Production years 1924-1935; 1937-1941; 1951; 1986-1990

Mining district

District name Buffalo Valley District
District name Battle Mountain District
District name Mill Canyon District\n

Land status

Ownership category BLM Administrative Area
Area name Battle Mountain BLM District
Ownership category Private

Ownership information

  • Type Owner-Operator
    Owner Fairmile Goldtech, Inc.
    Year 2004

Comments on the workings information

  • Historic underground workings aggregate 3000 feet and include 5 adits, one of which is 600 feet long and another 400 feet long. In addition, 40 shallow pits and trenches have been dug on the surface. Three levels, connected by stopes and raises, and an inclined shaft which extends 220 feet below the surface constitute the main underground workings. After 1988, development was by open pit methods. The buffalo valley mine and surrounding acreage totals over 18,000 acres.

Comments on other economic factors

  • Production was almost continuous from 1924 to 1941, and also in 1951. A 10-ton cyanidization plant was built in 1925 and 1196 tons of ore were treated by 1933. Total reported production through 1951 was approximately 3000 tons. More than 40,000 ounces of gold were produced from 1989 to 1991.
    In 1994, Fairmile GoldTech reported resources of about 700,000 ounces of gold in both underground and open pittable material.

Comments on development

  • Prospecting in the area of the Buffalo Valley Mine began in the 1860s with the discovery of gold placers. In 1916, Buffalo Valley Mines Co. purchased 28 unpatented claims from C. Ganser and others, which were then developed as the underground mine. Production was almost continuous from 1924 to 1941, and also in 1951. A 10-ton cyanidization plant was built in 1925 and 1196 tons of ore were treated by 1933. Total reported production through 1951 was approximately 3000 tons. Numerous independent exploration companies explored the Buffalo Valley Mine from the mid-1960s to 1985. In 1985, Horizon Gold Shares Inc. acquired a 99 year mining lease on 158 unpatented mining claims at the Buffalo Valley Mine. Horizon then expanded their land position by locating an additional 679 unpatented claims. At the time of Horizon's acquisition of the property, there existed a database collected from previous exploration efforts that consisted of over 200 short percussion drill holes, 7 diamond drill holes, 214 rotary drill holes, over 3000 gold assays collected from surface, underground, and drill hole samples, surface and underground geologic mapping, and metallurgical and feasibility studies. Horizon mined the Horizon as an open pit-heap leach operation from 1986 to 1990. In December, 1988, Horizon formed a joint venture with Chevron Resources Company to explore the Buffalo Valley property. In 1989, the Horizon/Chevron venture had discovered additional near surface gold occurrences in oxidized veins to the north, southwest, and east of the open pit and had identified an underground resource in gold-bearing oxidized veins beneath the existing pit. Fairmile Goldtech acquired the Buffalo Valley property in the early 1990s. Drilling on the property by Fairmile in 1994 established significant gold mineralization along the Front fault, a north-south striking, 40-50? west-dipping structure that has been traced for over 2,000 feet south of its intersection with the main Buffalo Valley structure. A geological resource within the Front fault zone of more than 350,000 ounces of gold was recognized. This is in addition to an underground geological resource in excess of 250,000 ounces of gold at the historic Buffalo Valley mine. At the Dore Hills prospect, about 3,000 feet north of the old Buffalo Valley pit, drilling confirmed the presence of similar mineralization with short intercepts in the 0.1 to 0.2 ounce per ton range.

Reference information

Bibliographic references

General comments

Subject category Comment text
Deposit The early orebodies that were mined underground were associated with the frontal fault striking N18E and dipping 40-55W. The more recently mined deposit developed by open pits strikes N30W and truncates against the frontal fault.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-FEB-2005 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.

External references

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.