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  3. Mineral Resource Data System (MRDS)

88 Group

Occurrence in Alaska, United States with commodity Gold
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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. Nearby scientific data
  9. Economic information about the deposit and operations
  10. Mining district
  11. Links to other databases
  12. Bibliographic references
  13. General comments
  14. Reporter information

Geologic information

Identification information

Deposit ID 10308546
Record type Site
Current site name 88 Group

Geographic coordinates

Geographic coordinates: -144.76492, 65.43274 (WGS84)
Relative position The 88 Group claims can be reached via an 8 mile long dirt road that starts in Circle Hot Springs. The claims are on the Portage Creek side of the divide along Portage Creek road.

Site location context

Political divisions (FIPS codes)

Yukon-Koyukuk(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Circle B-2(quadrangle 1:63,360 scale)

Circle SE(quadrangle 1:100,000 scale)

Circle(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Alaska(hydrologic region)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary

Materials information

Materials Type of material
Gold Ore

Alteration

  • Mineralization occurs within heavily Fe-stained, quartz-filled greisen zones of variable width (3 inch average). Phyllic and argillic alteration is present along vein margins and is also controllled by fractures (Bakke, 1991).

Nearby scientific data

(1) -144.76492, 65.43274
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = The 88 Group occurrence appears to be a dark mafic intrusive phase contact with a coarse porphyritic granite. Both lode and placer gold is found at these claims (Vetter, 1995). Wiltse and others (1995) mapped the bedrock in the area and described the Cretaceous granite as a chloritized porphyritic (hornblende) biotite monzogranite to syenogranite. They also mapped a mafic dike in the area of the 88 Group claims which is described as black to dark gray, aphanitic to slightly porphyritic with major plagioclase, augite, hornblende and magnetite. Gold mineralization occurs within heavily Fe-oxide stained, quartz-filled greisen zones (up to six feet across), within fractures, and in stockwork veining. A significant aspect of the prospect is the large amount of grus development, 10 to 20 feet, that pans considerable gold. Other heavy minerals concentrated in the pans include abundant sphalerite, and small amounts of arsenopyrite, chalcopyrite, cassiterite (?), and monazite (?). Continuous gold anomalies occur in the vicinity of the 88 Group discovery outcrop along approximately 2000 feet of ditch exposure along the Portage Creek road. The mineralization occurs within heavily Fe-oxide stained, quartz-filled greisen zones of variable width (3 inch average). Phyllic and argillic alteration is present along vein margins and is also controllled by fractures. Strong zinc anomalies (up to 0.5 percent) and moderate arsenic values are present. Tin was not detected in the rock samples, however, two pan concentrates contain anomalous values. The dominant trend in mineralization is N 50 W with near vertical dips (Bakke,1991).

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Circle

Comments on the workings information

  • Workings / Exploration = Exploration was restricted to surface sampling.

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Vetter, 1995.

General comments

Subject category Comment text
Deposit Model Name = Gold-bearing greisen zones in granite.

Reporter information

Type Date Name Affiliation Comment
Reporter 15-SEP-1998 C.J. Freeman, J.R. Guidetti Schaefer, A.S. Clements Avalon Development Corporation

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.