Unnamed (west of Rendu Glacier)

Occurrence in Alaska, United States with commodities Silver, Gold, Copper, Tungsten, Zinc
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. Host and associated rocks
  10. Nearby scientific data
  11. Economic information about the deposit and operations
  12. Mining district
  13. Links to other databases
  14. Bibliographic references
  15. General comments
  16. Reporter information

Geologic information

Identification information

Deposit ID 10002216
MRDS ID A013117
Record type Site
Current site name Unnamed (west of Rendu Glacier)
Related records 10258098

Geographic coordinates

Geographic coordinates: -136.80213, 59.02972 (WGS84)
Relative position This occurrence is in Glacier Bay National Park and Preserve at an elevation of about 5,000 feet near the top of the steep west face of a ridge west of Rendu Glacier. It is in the SE1/4, section 6, T. 33 S., R. 52 E. of the Copper River Meridian. It corresponds to sample sites 65048 to 65050 on Figure C-44 in Brew and others (1978). Location 3 of Cobb (1972; MF-424), which refers to the 'Rendu Glacier' deposit, is probably the same occurrence but is shown about 0.5 miles farther to the west and is considered to be a less accurate location. Still (1991 [BOM, v. 2, sec A) refers to this as the 'Massive Chalcopyrite Deposit.'? The deposit is extremely inaccessible. It can only be reached from a helicopter landing site on the ridge by a 200 foot rappel down a vertical to overhanging cliff that continues down for another 3,000 feet.

Site location context

Political divisions (FIPS codes)

Hoonah-Angoon(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Skagway A-5(quadrangle 1:63,360 scale)

Skagway SW(quadrangle 1:100,000 scale)

Skagway C(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Glacier Bay(hydrologic unit)

Northern Southeast Alaska(hydrologic accounting unit)

Southeast Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Glacier Bay National Park(National Park)

National Park NPS(Type of land area)

NPS(Federal land areas administered by NPS)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Gold Primary
Copper Primary
Tungsten Critical Primary
Zinc Critical Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Goethite Ore
Pyrite Ore
Pyrrhotite Ore
Sphalerite Ore
Augite Gangue

Alteration

  • (Local) Skarn, tactite.

Mineral occurrence model information

Model code 58
USGS model code 18a
Deposit model name Porphyry Cu, skarn-related
Mark3 model number 9
Model code 72
USGS model code 19a
Deposit model name Polymetallic replacement
Mark3 model number 47

Host and associated rocks

  • Host or associated Host
    Rock type Metamorphic Rock > Metasedimentary Rock > Marble

Nearby scientific data

(1) -136.80213, 59.02972

Economic information

Comments on the geologic information

  • Geologic Description = The following description is summarized from Brew and others (1978).?A massive-sulfide zone is located between a 5-foot-wide epidote-bearing diorite zone grading into white diorite to the south and a 10-foot-wide section of calc-silicate rock grading into marble to the north. The calc-silicate rock is predominately garnet, epidote, and diopside with thin sulfide and scheelite veins. The massive-sulfide zone consists of chalcopyrite, augite, goethite, pyrrhotite, scheelite, and sphalerite; the augite and scheelite is replaced by chalcopyrite and pyrrhotite. The mineralization probably formed as a result of metasomatic replacement of marble in a high temperature contact zone. The sulfide zone is 12 feet wide by 80 feet long. The average grade of two samples across the zone is 0.52% tungsten, 5% copper, 7 ounces of silver per ton, and 0.15 ounce of gold per ton. Four of seven grab samples from the 10-foot-wide calc-silicate zone contained from 159 to 11,000 ppm tungsten. Similar mineralization is present elsewhere in the vicinity of this occurrence, but access is limited because of the steep terrain. The mineralization is probably Cretaceous or younger in age, based on the age of the diorite that hosts this occurrence.
  • Age = Probably Cretaceous based on the age of the diorite that hosts this occurrence (Brew and others, 1978).

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Juneau (Skagway subdistrict)

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Brew and others, 1978

General comments

Subject category Comment text
Deposit Model Name = Skarn, contact metasomatic (Cox and Singer, 1986; model 18a or 19a).
Deposit Other Comments = the deposit is within Glacier Bay National Park and Preserve where exploration and development is restricted.

Reporter information

Type Date Name Affiliation Comment
Reporter 04-FEB-2001 T.C. Crafford T. Crafford & Associates

Beyond USGS

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

Authoritative Alaska resources

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