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

Unnamed (Northwest part of Yakobi Island)

Occurrence in Alaska, United States with commodities Copper, Nickel, PGE
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Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Commodities
  6. Nearby scientific data
  7. Economic information about the deposit and operations
  8. Mining district
  9. Links to other databases
  10. Bibliographic references
  11. General comments
  12. Reporter information

Geologic information

Identification information

Deposit ID 10307807
Record type Site
Current site name Unnamed (Northwest part of Yakobi Island)

Geographic coordinates

Geographic coordinates: -136.55206, 58.04971 (WGS84)
Relative position The location is at sea level on the west coast of Yakobi Island about 1.5 miles west of Hoktaheen Lake (Rossman, 1959, plate 12). Location is accurate within about 0.1 mile.

Site location context

Political divisions (FIPS codes)

Hoonah-Angoon(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Mount Fairweather A-2(quadrangle 1:63,360 scale)

Mount Fairweather SE(quadrangle 1:100,000 scale)

Mount Fairweather(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Central Southeast Alaska(hydrologic accounting unit)

Southeast Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Tongass National Forest(National Forest)

National Forest FS(Type of land area)

FS(Federal land areas administered by FS)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Copper Primary
Nickel Critical Primary
PGE Critical Primary

Nearby scientific data

(1) -136.55206, 58.04971
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = A gabbro body on northern Yakobi Island is geologically permissive for nickel-copper deposits similar to those that occur at Takanis and Bohemia Basin in the Sitka D-8 quadrangle, about two miles south of the southern boundary of the Mt. Fairweather A-2 quadrangle. (The gabbro body on Mt. Fairweather A-2 quadrangle is about 6 miles northwest of the Takanis nickel-copper deposit.) the structural setting on the northwest part of Yakobi Island is the same as at Bohemia Basin where barren and ore- bearing gabbro occur within the same large dike-like intrusion of non-foliated light colored sodic quartz diorite of Tertiary age that hosts the gabbro body on Fairweather A-2. The dike-like quartz diorite mass crops out for about seven miles on the Mt. Fairweather quadrangle; to the south, it thickens, becomes more complex, and extends into the Sitka quadrangle for about ten more miles (Rossman, 1959, plate 12; Loney and others, 1975, plates 1 and 2). The eastern part of the gabbro body on northern Yakobi Island is on the mainland of the island; much of the body is on an offshore island complex. Nickel-bearing norite gabbro is unknown at the occurrence, but the intrusion is large enough to host nickel-copper deposits in the body, especially the part exposed on small islands and largely covered by sea water.
  • Age = Tertiary.

Economic information about the deposit and operations

Development status Occurrence

Comments on exploration

  • Status = Inactive

Mining district

District name Chicagof

Comments on the workings information

  • Workings / Exploration = None.

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Rossman, 1959 (B 1058-E)

General comments

Subject category Comment text
Deposit Model Name = Igneous-affiliated deposit, mafic to ultramafic.
Deposit Other Comments = the gabbro body is in the West Chichagof-Yakobi Island Wilderness Area of the Tongass National Forest.

Reporter information

Type Date Name Affiliation Comment
Reporter 04-APR-99 Hawley, C.C. Hawley Resource Group

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.