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Taurus

Prospect in Alaska, United States with commodities Copper, Molybdenum, Gold
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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. Economic information about the deposit and operations
  13. Mining district
  14. Ownership information
  15. Reserves and resources
  16. Links to other databases
  17. Bibliographic references
  18. General comments
  19. Reporter information

Geologic information

Identification information

Deposit ID 10094054
MRDS ID A012535
MAS/MILS ID 0020690064
Record type Deposit
Current site name Taurus
Alternate or previous names East Taurus, West Taurus

Geographic coordinates

Geographic coordinates: -141.35262, 63.64975 (WGS84)
Relative position The Taurus prospect is located in section 28, T. 22 N., R. 21 E., of the Copper River Meridian. Access to the property is by air, and there are two gravel airstrips on the property. Alternatively, a rough land route is available for heavy equipment via a winter trail (Leriche, 1995, p. 451). This is locality 5 of Eberlein and others (1977). Bluff prospect (TC005) claims lie directly to the west, and the center of Bluff prospect (TC005) prospecting activity lies to the southwest. The location is accurate to within 1 mile.

Site location context

Political divisions (FIPS codes)

Southeast Fairbanks(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Tanacross C-1(quadrangle 1:63,360 scale)

Tanacross NE(quadrangle 1:100,000 scale)

Tanacross(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Alaska(hydrologic region)

Geographic areas

Country State
United States Alaska

Public Land Survey System information

Meridian Township Range Section Fraction State
Copper River 22N 21E 28 Alaska

Commodities

Commodity Importance
Copper Primary
Molybdenum Primary
Gold Primary

Materials information

Materials Type of material
Chalcocite Ore
Chalcopyrite Ore
Covellite Ore
Magnetite Ore
Molybdenite Ore
Pyrite Ore
Fluorite Gangue
Quartz Gangue
Sericite Gangue
Tourmaline Gangue

Alteration

  • (Local) Hypogene alteration associated with mineralization includes argillic, potassic, phyllic, silicic, and propylitic alteration of varying intensities. A supergene leached cap, approximately 50 meters thick, exhibits strong argillic alteration over the East and West Taurus zones (Leriche, 1995).

Mineral occurrence model information

Model code 79
USGS model code 21a
Deposit model name Porphyry Cu-Mo
Mark3 model number 2

Host and associated rocks

  • Host or associated Associated
    Rock type Metamorphic Rock > Gneiss
  • Host or associated Host
    Rock type Plutonic Rock > Granitoid > Quartz Monzonite

Nearby scientific data

(1) -141.35262, 63.64975
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = The Taurus property is usually separated into two main zones: West Taurus and East Taurus. The property is underlain in part by a metamorphic basement complex of possible Late Precambrian or early Paleozoic age that consists of biotite gneiss, augen gneiss, biotite schist, and quartzite (Foster, 1970). Early Tertiary felsic rocks intrude the metamorphic rocks. Secondary biotite within the intrusion at the Taurus prospect has been dated by K-Ar techniques to be approximately 57 +/- 2 Ma (Nokleberg and others, 1995). ? Two major faults have been identified on the property. The Tourmaline fault strikes northeasterly and appears to have left-lateral movement with a possible displacement of up to 6.5 km. The McCord Creek fault trends easterly across the claims. Porphyry intrusions, which host mineralization at the East and West Taurus zones, are located near the McCord Creek fault, suggesting that it controlled their emplacement. Many northeast trending linears have been interpreted using satellite images and topographic maps (Leriche, 1995, p. 452).? the Taurus porphyry copper-type mineralization appears to be related to a group of widespread, small bodies of early Tertiary, quartz monzonite porphyry, quartz latite, feldspar-quartz porphyry, intrusive breccia, quartz porphyry and dacite porphyry. Intrusive breccia crops out along the southern border of an altered Upper Cretaceous granodioritic pluton on the eastern side of the property. Quartz monzonite porphyry occurs along the southern contacts of the altered granodiorite and of intrusive breccia in the central part of the property (Leriche, 1995, p. 452). ? the alteration at the East Taurus zone consists of an upper leached cap underlain by supergene and hypogene zones. The leached cap varies from 40 to 50 meters in depth, and shows pervasive argillic alteration due to groundwater leaching. Other alteration types in the leached cap consist of pervasive silicification, quartz-sericite, and quartz-magnetite alteration. Supergene and hypogene zones are accompanied by phyllic, silicic, propylitic, and potassic alteration (Leriche, 1995, p. 453).?Mineralization in the leached cap at East Taurus consists of minor remnant pyrite, chalcopyrite, and molybdenite in quartz stockworks and silicified zones. The supergene zone varies in thickness from 30 meters to 53 meters. Mineralization in it consists of chalcocite, covellite, pyrite, chalcopyrite, and molybdenite. Chalcocite appears in fractures and within quartz veinlets. In the lower hypogene zone, mineralization is pyrite, chalcopyrite, and molybdenite as disseminations along fractures and in the center of quartz veinlets (Leriche, 1995, p. 453).? Mineralization in the West Taurus area consists of pyrite and subordinate chalcopyrite, covellite, chalcocite, malachite, and azurite. Molybdenite is found in quartz-filled fractures in the sericitically altered, quartz latite unit. Chalcopyrite and molybdenite are found as fracture fillings in close proximity to the Tourmaline and McCord Creek faults (Leriche, 1995, p. 454).? the majority of drilling conducted on the property has been done in the East Taurus zone. In 1993, Noranda calculated preliminary reserves of 23 million tons grading 0.3% Cu and 0.039% Mo. Drill samples collected in the 1970's were not assayed for gold, but later analyses of part of the core reveals some elevated values in gold (Leriche, 1995, p. 455).? Resource Associates of Alaska re-staked the Taurus and Bluff (TC005) prospects in 1987 and did some soil geochemistry. They dropped both properties two years later. They probably analyzed for gold and may not have found enough to continue holding the property.
  • Age = Secondary biotite within the intrusion at the Taurus prospect has been dated by K-Ar techniques as approximately 57 +/- 2 Ma (Nokleberg and others, 1995).

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic
Significant Yes

Comments on exploration

  • Status = Active

Mining district

District name Fortymile

Ownership information

  • Type Owner-Operator
    Owner Lodestar Explorations Ltd.
    Interest 100
    Home office Canada
    Year 1992

Comments on the ownership information

  • HEMLO GOLD MINES LTD. DROPPED OPTION FOR 50% OF TAURUS IN 1992.

Reserves and resources

  • Type In-situ
    Estimate year 1992
    Total resources 127000000mt ore
    Commodity Subtype Grade units Group Importance Year
    Gold 0.3 g/mt Gold Primary 1992
    Molybdenum 0.03 wt-pct Molybdenum Primary 1992
    Copper 0.3 wt-pct Copper Primary 1992

Comments on the reserve resource information

  • Reserves = In 1993, Noranda indicated that the East Taurus zone contains a 23 million ton reserve grading 0.3% Cu and 0.039% Mo (Leriche, 1995).

Comments on the workings information

  • Workings / Exploration = Taurus prospect was staked in 1970 by International Minerals and Chemical Corporation during a reconnaissance geochemical survey. During the 1970's, geologic mapping, soil sampling, magnetometer and IP surveys, and 3060 meters of diamond and rotary drilling were done. In recent years, an airborne magnetic, electromagnetic, and resistivity survey, as well as 404 meters of reverse circulation drilling have been done (Leriche, 1995, p. 451). ? In 1987, Resource Associates of Alaska staked the Taurus and Bluff (TC005) prospects, but dropped both 2 years later. Noranda staked Taurus in 1993.

Reference information

Bibliographic references

  • Deposit

    Foster, H.L., 1970, Reconnaissance geologic map of the Tanacross quadrangle, Alaska: U.S. Geological Survey Miscellaneous Geological Investigations Map I-593, 1 sheet, scale 1:250,000.

  • Deposit

    Singer, D.A., Csejtey, Bela, Jr., and Miller, R.J., 1978, Map and discussion of the metalliferous and selected nonmetalliferous mineral resources of the Talkeetna Mountains quadrangle, Alaska: U.S. Geological Survey Open-file Report 78-588-Q, 33 p., 1 plate, scale 1:250,000.

  • Deposit

    Eberlein, G.D., Chapman, R.M., Foster, H.L., and Gassaway, J.S., 1977, Map and table describing known metalliferous and selected nonmetalliferous mineral deposits in central Alaska: U.S. Geological Survey Open-File Report 77-168-D, 132 p., 1 map, scale 1:1,000,000.

  • Deposit

    Gill, R., 1977, Geology and mineral deposits of the southwest quarter of the Tanacross D-1 quadrangle, Alaska: Golden, Colorado School of Mines, M.Sc. thesis, 129 p.

  • Deposit

    Cobb, E.H., and Eberlein, G.D., 1980, Summaries of data on and lists of references to metallic and selected nonmetallic mineral deposits in the Big Delta and Tanacross quadrangles, Alaska: U.S. Geological Survey Open-File Report 80-1086, 77 p.

  • Deposit

    Nokleberg, W.J., Bundtzen, T.K., Berg, H.C., Brew, D.A., Grybeck, D.J., Robinson, M.S., Smith, T.E., and Yeend, W., 1987, Significant metalliferous lode deposits and placer districts of Alaska: U.S. Geological Survey Bulletin 1786, 104 p.

  • Deposit

    Leriche, P.D., 1995, Taurus copper-molybdenum porphyry deposit, east-central Alaska: in Schroeter, T.G., ed., Porphyry Deposits of the Northwestern Cordillera: Canadian Institute of Mining, Metallurgy, and Petroleum Special Volume 46, p. 451-457.

  • Deposit

    Nokleberg, W.J., Bundtzen, T.K., Brew, D.A., and Plafker, G., 1995, Metallogenesis and tectonics of porphyry copper and molybdenum (gold, silver) and granitoid-hosted gold deposits of Alaska: Canadian Institute of Mining and Metallurgy Special Volume 46, p. 103-141.

  • Deposit

    Singer, D.A., Curtin, G.C., and Foster, H.L., 1976, Mineral resources map of the Tanacross Quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies 767-E, 1 sheet, scale 1:250,000.

  • Deposit

    THE MINING RECORD, 4/7/93

  • Ownership

    NORTHERN MINER, 5/4/92

  • Reserve-Resource

    NORTHERN MINER, 3/9/92

  • Deposit

    Newberry, R.J., Layer, P.W., Burleigh, R.E., and Solie, D.N., 1996, New 40Ar/39Ar dates for intrusions and mineral prospects in the eastern Yukon-Tanana terrane, Alaska - Regional patterns and significance, in Gray, J.E., and Riehle, J.R., eds., Geological Studies in Alaska by the U.S. Geological Survey, 1996: U.S. Geological Survey Professional Paper 1595, p. 131-159.

Comments on the references

  • Primary Reference = Leriche, 1995

General comments

Subject category Comment text
Deposit Model Name = Porphyry Cu-Mo deposit (Cox and Singer, 1986; model 21a)
Deposit Other Comments = See also the Pushbush prospect (TC024) and the ASARCO prospect (TC001).

Reporter information

Type Date Name Affiliation Comment
Reporter 13-APR-99 Cameron, C.E. Alaska Division of Geological and Geophysical Surveys
Editor 22-SEP-09 Damon Bickerstaff U.S. Geological Survey
Reporter 19-MAR-97 Porter, Kenneth E. U.S. Bureau of Mines

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Maps centered on this site

Authoritative Alaska resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.