1. Mineral Resources
  2. Online Spatial Data
  3. Mineral Resource Data System (MRDS)

Highway

Prospect in Alaska, United States with commodities Gold, Chromium, Copper, Palladium, Platinum
Map
XML
JSON
KML
B
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 10000972
MRDS ID A011643
Record type Site
Current site name Highway

Geographic coordinates

Geographic coordinates: -149.20265, 61.46955 (WGS84)
Relative position Prospect occurs where rocks outcrop on the south side of the Old Glenn highway, north of West Twin Peak. Location is accurate within 500 ft. This is the 'Highway Area' of Rose (1966), locality 42 of Cobb (1972), and locality 32 of MacKevett and Holloway (1977).

Site location context

Political divisions (FIPS codes)

Matanuska-Susitna(Borough)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Anchorage B-6(quadrangle 1:63,360 scale)

Anchorage SW(quadrangle 1:100,000 scale)

Anchorage(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Matanuska(hydrologic unit)

Knik Arm(hydrologic accounting unit)

South Central Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Eklutna, Incorporated(ANCSA Village)

ANCSA Village NTVPIC(Type of land area)

NTVPIC(Federal land areas administered by NTVPIC)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary
Chromium Critical Primary
Copper Primary
Palladium Critical Secondary
Platinum Critical Secondary

Comments on the commodity information

  • Ore Material = Copper (native)

Materials information

Materials Type of material
Chromite Ore
Gold Ore
Copper Ore

Alteration

  • (Local) Slight serpentinization of olivine

Mineral occurrence model information

Model code 15
USGS model code 8a
Deposit model name Podiform chromite (minor)
Mark3 model number none
Model code 23
USGS model code 9
Deposit model name Alaskan Cr-Pt (PGE)
Mark3 model number 120

Nearby scientific data

(1) -149.20265, 61.46955
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = Bjorklund and Wright (1948) and Rose (1966) report chromite deposits in Lower to Middle Jurassic dunite found near base of the Eklutna ultramafic body. Near the highway the chromite bands are oriented N 17 E, 85 NW . The chromite-bearing zone is 8 ft wide and contains discontinuous stringers and lenses of chromite from 1/4 to 1 inches wide. The bands are composed of euhedral chromite grains 1-2 mm in diameter in a matrix of olivine and minor clinopyroxene. The chromite bands are displaced as much as 5 ft by minor faults (Bjorklund and Wright, 1948). The dominant rock types are peridotite-dunite and hornblendite-pyroxenite (Clark and Greenwood, 1972). A banded chromite sample (Rose, 1966) was found to contain free gold and native copper.? the weighted average of samples collected in 10 trenches at the prospect had a grade of 5.7 percent chromite. The grade of the rock generally decreases going uphill. Rose (1966) reports that an 8 ft wide road-cut sample averaged 11.5 percent chromite; one 8 inch wide chromite band contained 25.8 percent chromite. Of 16 samples collected by Clark and Greenwood (1972), 12 contained an average value of 0.042 ppm Pt and 0.060 ppm Pd.
  • Age = Early to Middle Jurassic

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Anchorage

Comments on the workings information

  • Workings / Exploration = Exploration is limited to 10 trenches and 1 diamond-drill hole completed by U.S. Bureau of Mines in 1942 (Bjorklund and Wright, 1948). The weighted, average grade of samples collected in 10 trenches at the prospect was 5.7 percent chromite. The grade generally decreased uphill. Rose (1966) reported that an 8-foot-wide, road-cut sample averaged 11.5 percent chromite; one 8-inch chromite band contained 25.8 percent chromite. Of 16 samples collected by Clark and Greenwood (1972), twelve contained an average value of 0.042 ppm Pt and 0.060 ppm Pd.

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Rose, 1966

General comments

Subject category Comment text
Deposit Model Name = Podiform chromite or Alaskan PGE (Cox and Singer, 1986; models 8a or 9)
Deposit Other Comments = Deposit too small and too low grade to be minable under conditions prevailing in 1940's (Bjorklund and Wright, 1948).

Reporter information

Type Date Name Affiliation Comment
Reporter 30-JUL-1998 D.P. Bickerstaff U.S. Geological Survey
Reporter 30-JUL-1998 S.W. Huss U.S. Geological Survey

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.