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Mystery Mountains East

Prospect in Alaska, United States with commodities Copper, Silver, Arsenic, Antimony
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Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Commodities
  6. Materials information
  7. Alteration
  8. Mineral occurrence model information
  9. Nearby scientific data
  10. Economic information about the deposit and operations
  11. Mining district
  12. Links to other databases
  13. Bibliographic references
  14. General comments
  15. Reporter information

Geologic information

Identification information

Deposit ID 10307778
Record type Site
Current site name Mystery Mountains East

Geographic coordinates

Geographic coordinates: -154.56297, 63.52349 (WGS84)
Relative position The Mystery Mountains East prospect is situated on a steep southerly flank of a southwest facing valley about 2 miles (3.2 km) north of Cottonwood Creek at an elevation of 3,400 feet (1,036 m) in Section 2, T. 23 S., R. 22 E., of the Kateel River Meridian. Location is accurate to within 500 feet (152 m).

Site location context

Political divisions (FIPS codes)

Yukon-Koyukuk(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Medfra C-4(quadrangle 1:63,360 scale)

Medfra N(quadrangle 1:100,000 scale)

Medfra C(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Alaska(hydrologic region)

Federal lands

Doyon, Limited(ANCSA Region)

ANCSA Region NTVPIC(Type of land area)

NTVPIC(Federal land areas administered by NTVPIC)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Copper Primary
Silver Secondary
Arsenic Critical Secondary
Antimony Critical Secondary

Materials information

Materials Type of material
Arsenopyrite Ore
Chalcopyrite Ore
Pyrite Ore
Stibnite Ore
Quartz Gangue
Tourmaline Gangue

Alteration

  • (Local) Biotite, tourmaline, and quartz.

Mineral occurrence model information

Model code 78
USGS model code 20c
Deposit model name Porphyry Cu-Au
Mark3 model number 34

Nearby scientific data

(1) -154.56297, 63.52349
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = The Mystery Mountains East prospect is one of a number of porphyry-like copper-gold prospects that occur along a seven mile (11 km) long, northeast trending belt through the central Mystery Mountains. Mineralization consists of tourmaline quartz veins, breccia veins, and fractures associated with small monzonite and quartz porphyry bodies hosted in biotite hornfels (DiMarchi and others, 1997). Sulfides include arsenopyrite, chalcopyrite, pyrite, and traces of stibnite, within a 600 feet by 600 feet (183 m by 183 m) area. The Mystery Mountain East prospect is inferred to be Late Cretaceous, based on isotopic ages from Mystery Mountains plutonic rocks (Moll and others, 1981). Surface grab samples from the Mystery Mountains East prospect ran as high as 830 ppm arsenic, 203 ppm copper, 2.0 ppm silver, but contained no gold (DiMarchi and others, 1997).
  • Age = the Mystery Mountain East prospect is inferred to be Late Cretaceous, based on isotopic ages from Mystery Mountains plutonic rocks (Moll and others, 1981).

Economic information about the deposit and operations

Development status Prospect

Comments on exploration

  • Status = Inactive

Mining district

District name McGrath

Comments on the workings information

  • Workings / Exploration = WGM Inc. located a number of porphyry-like prospects in the Mystery Mountains during the late 1970s (Andrews, 1978). From 1988 to 1990, ACNC conducted detailed exploration work, which included an airborne geophysical survey. ASA Inc. continued work from 1991 to 1997. Surface grab samples from the Mystery Mountains East prospect ran as high as 830 ppm arsenic, 203 ppm copper, 2.0 ppm silver, but contained no gold (DiMarchi and others, 1997).

Reference information

Bibliographic references

  • Deposit

    Andrews, Tom, 1978, Summary of Progress, Doyon Project, Mystery Mountains, (Block 10): Anchorage, Alaska, WGM Inc., 24 pages (Held by Doyon Ltd., as proprietary report 78-42).

  • Deposit

    Moll, E.J., Silberman, M.L., and Patton, W.W. Jr., 1981, Chemistry, mineralogy, and K-Ar ages of igneous and metamorphic rocks of the Medfra quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-811C, 15 p., 2 sheets, scale 1:250,000.

  • Deposit

    DiMarchi, J.J., and Frantz, P.S., 1997, Annual Report for 1997-Doyon Option Lands, Block 10: ASA Inc.-Montague Gold Joint Venture Report, Volume II: Unpublished report, 189 p. (Report held by Doyon, Limited, Fairbanks, Alaska.)

Comments on the references

  • Primary Reference = DiMarchi and others, 1997

General comments

Subject category Comment text
Deposit Model Name = Porphyry Cu-Au (Cox and Singer, 1986; model no. 20c)
Deposit Other Comments = See Copenhagen Hill (MD030), Frozen Creek (MD032), Tarn (MD027), and Pork Chop (MD031) prospects.

Reporter information

Type Date Name Affiliation Comment
Reporter 06-JUN-98 Bundtzen, T.K. Pacific Rim Geological Consulting

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.