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Michigan Lode

Prospect in Alaska, United States with commodities Gold, Silver, Copper, Lead, 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. Nearby scientific data
  8. Economic information about the deposit and operations
  9. Mining district
  10. Links to other databases
  11. Bibliographic references
  12. General comments
  13. Reporter information

Geologic information

Identification information

Deposit ID 10308783
MRDS ID A012482
Record type Site
Current site name Michigan Lode
Alternate or previous names Michigan Lead
Related records 10001700

Geographic coordinates

Geographic coordinates: -144.19778, 64.36072 (WGS84)
Relative position The Michigan Lode is situated on a ridge of Black Mountain separating the headwaters of Antimony Creek, a tributary of Tibbs Creek (BD040), and Summitt Creek, a tributary of Boulder Creek (BD004). The prospect is located in the SW1/4SW1/4 section 28, T. 6 S., R. 18 E., of the Fairbanks Meridian, approximately 54 miles east-northeast of Delta Junction, Alaska. A winter trail from the South Fork of the Goodpaster River provides access up Divide Creek. There are numerous surface workings at and surrounding the site. The site is incorrectly labeled on current U.S.G.S. maps as a mine. It was not identified as a separate location by Cobb (1972) or by Cobb and Eberlein (1980). Approximately one mile north of the Michigan Lode, U.S.G.S. maps note some mining activity on the ridge between Wolverine Creek and Antimony Creek in the SW1/4SE1/4 section 20, T. 6 S., R. 18 E., of the Fairbanks Meridian.

Site location context

Political divisions (FIPS codes)

Southeast Fairbanks(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Big Delta B-1(quadrangle 1:63,360 scale)

Big Delta SE(quadrangle 1:100,000 scale)

Big Delta(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Alaska(hydrologic region)

Federal lands

BLM(Federal land areas administered by BLM)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary
Silver Secondary
Copper Secondary
Lead Secondary
Antimony Critical Secondary

Materials information

Materials Type of material
Arsenopyrite Ore
Covellite Ore
Digenite Ore
Gold Ore
Jamesonite Ore
Pyrite Ore
Stibnite Ore
Quartz Gangue

Nearby scientific data

(1) -144.19778, 64.36072
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = The topography of the area is characterized by rounded hills and flat-topped ridges (Thomas, 1970). The most prominent ridge is Black Mountain, which trends about 12 miles in a northerly direction and is underlain by Cretaceous granodiorite (Weber and others, 1978). Several creeks flow westward off Black Mountain in steep, parallel, V-shaped valleys to form the headwaters of Tibbs Creek. A combination of augen gneiss, gneissic schist, and schist are to the west of Black Mountain. There is intense shearing and faulting in the contact between the metamorphic and intrusive rocks. This shearing is observed in the underground workings and at the surface as pronounced saddle-like depressions across the spurs separating the westward-flowing tributaries of Tibbs Creek. This shear zone trends roughly N15E and dips 65 degrees NW. The lode deposits in the area are gold-bearing quartz veins in the shear zone. Most of the veins are in the shear zone, although some are in the intrusive rocks. The quartz veins contain gold and a variable assemblage of sulfides, including arsenopyrite, covellite, digenite, jamesonite, pyrite, and stibnite. Typically, gold content decreases as sulfides increase. Veins are commonly 2 to 3 feet in width, with some as wide as 8 feet (Thomas, 1970). When gold is present, it is usually extremely fine grained. However, several veins such as the Blue Lead mine (BD003) and Grizzly Bear mine (BD018) contain relatively coarse gold, which is easily visible in hand specimen. Thomas (1970) describes the Michigan Lode as a surface vein. Assays from the site show 0.10 ounce/ton Au from vein quartz with a blue hue, and 0.42 ounce/ton Au and 0.08 ounce/ton Ag from some Fe-stained quartz (Thomas, 1970). The mining activity noted on U.S.G.S. maps on the ridge between Wolverine Creek and Antimony Creek is described by Thomas (1970) as trenches. An assay of a sample containing cryptocrystalline quartz with a blue cast showed 8.76 ounces/ton Au and 3.26 ounces/ton Ag (Thomas, 1970). The Goodpaster region was first explored for placer gold in 1915. In the early 1930's, gold-bearing quartz veins were discovered in the upper Tibbs Creek area. By the winter of 1936, the first underground workings were being installed. The original base camp was on Summit Creek. A 450 foot tunnel was driven following a small vein, termed the Blue Lead Extension. After disappointing results, the work was stopped. In the summer of 1936, five men drove a 300-foot tunnel at the outcrop of the Blue Lead vein (Reed, 1937). During the winter of 1937, a 300-foot tunnel was driven at the Grizzly Bear mine (BD018) and a 50-ton mill was constructed. In the summer of 1938, the mill was moved to the Blue Lead mine and operated for a year and a half until the fall of 1939 (Joesting, 1938). There was been limited exploration reported in the 1970's. The mill was still on site and the mine shaft opening were accessible in 1970, but blocked by ice (Thomas, 1970). It is reported that 350 tons of ore was produced from the Grizzly Bear mine and processed at the mill. This is compared with 150 tons from the Blue Lead mine (Reed, 1937). No ore was mined from the Michigan Lode (Thomas, 1970).
  • Age = Postdates Cretaceous granodiorite intrusion

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Goodpaster

Comments on the production information

  • Production Notes = It is reported that 350 tons of ore was produced from the nearby Grizzly Bear Mine and 150 tons from the Blue Lead Mine (Reed, 1937). No ore was mined from the Michigan Lode (Thomas, 1970).

Comments on the workings information

  • Workings / Exploration = The Goodpaster region was first explored for placer gold in 1915. In the early 1930's, gold-bearing quartz veins were discovered in the nearby upper Tibbs Creek area. By the winter of 1936, the first underground workings were being installed. The original base camp was on Summit Creek. A 450-foot tunnel was driven following a small vein, termed the Blue Lead Extension. After disappointing results, the work was stopped. In the summer of 1936, five men drove a 300-foot tunnel at the outcrop of the Blue Lead vein. (Reed, 1937). During the winter of 1937, a 300-foot tunnel was driven at the Grizzly Bear Mine along with the construction of a 50-ton amalgamation recovery mill. In the summer of 1938, the mill was moved to the Blue Lead Mine and operated for 1.5 years until the fall of 1939 (Joesting, 1938). There has been limited exploration reported in the 1970's. The mill is still on site and the mine shaft opening is accessible, but blocked by ice (Thomas, 1970). It is unknown if any development took place at the Michigan Lead Mine.

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Thomas, 1970

General comments

Subject category Comment text
Deposit Model Name = Shear-hosted magmatic-hydrothermal vein

Reporter information

Type Date Name Affiliation Comment
Reporter 26-APR-1999 Cameron S. Rombach Alaska Division of Geological and Geophysical Surveys

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.