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Gray Lead

Past Producer 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. Host and associated rocks
  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 10001705
MRDS ID A012487
Record type Site
Current site name Gray Lead
Related records 10233998

Geographic coordinates

Geographic coordinates: -144.25167, 64.34278 (WGS84)
Relative position The Gray Lead mine is situated on a ridge extending northwest from Black Mountain, just south of the headwaters of King Creek, a tributary of Tibbs Creek (BD040). The mine is located at NE1/4NW1/4 section 6, T. 7 S., R. 18 E., of the Fairbanks Meridian, approximately 54 miles northeast of Delta Junction. Winter trails up Tibbs Creek and the South Fork of the Goodpaster River provide access up Divide Creek to the top of Black Mountain. There are numerous surface workings at and surrounding the site. The Gray Lead mine is not labeled on current U.S.G.S. maps. It is locality 3 of Cobb and Eberlein (1980) who summarized relevant references under the name 'Gray Lead'.

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)

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

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Granitoid > Granite
    Stratigraphic age (youngest) Late Cretaceous
  • Host or associated Host
    Rock type Plutonic Rock > Granitoid > Granite

Nearby scientific data

(1) -144.25167, 64.34278
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = 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 a 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. Bordering Black Mountain to the west is a combination of augen gneiss, gneissic schist, and schist. 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 found in intrusive rocks. The veins contain gold and a variable combination 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 nearby veins such as the Blue Lead mine (BD003) and Grizzly Bear mine (BD018) contain relatively coarse gold, which is easily visible in hand specimen. ? the Gray Lead mine is centered on a quartz vein 2 feet in width. Based on underground workings, the vein dips steeply to the west (Joesting, 1938). Foster and others (1978) performed two emission spectroscopy analyses on rock samples from the Gray Lead mine: sample 74WR-181c contained greater than 10,000ppm As, 15 ppm Ba, 150 ppm Bi, 5 ppm Co, 1 ppm Cr, 7 ppm Cu, 50 ppm Pb, 500 ppm Se, and 4.0 ppm Au; and sample 74WR-181d contained 10,000ppm As, 30 ppm B, 300 ppm Ba, 10 ppm Bi, 2 ppm Cr, 50 ppm Cu, 50 ppm La, 5 ppm Nb, 7 ppm Pb, 7 ppm Sc, 20 ppm Sn, 7 ppm Sr, 30 ppm V, 15 ppm Y, 70 ppm Zr, and 1.5 ppm Au.? 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 along 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). Subsequently, from 1939 to 1941, approximately 1,300 feet of surface and subsurface workings were completed at the Gray Lead mine (Thomas, 1970). Over 300 feet of the vein was traced at the surface(Joesting, 1938). There was limited exploration reported in the 1970's. The mine shaft opening was accessible, but blocked by ice (Thomas, 1970). It is reported that 350 tons of ore was produced from the nearby Grizzly Bear mine and processed at the mill at the Blue Lead mine. Another 150 tons was produced from the Blue Lead mine (Reed, 1937). Thomas (1970) reports that no ore from the Gray Lead mine was taken to the mill. It is unknown how much, if any, ore was processed elsewhere.
  • Age = Postdates Cretaceous granodiorite intrusion

Economic information about the deposit and operations

Development status Past Producer
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 Grizzly Bear mine and processed at the mill at the Blue Lead mine. Another 150 tons was produced from the Blue Lead mine (Reed, 1937). Thomas (1970) reports that no ore from the Gray Lead mine was taken to the mill. It is unknown how much, if any, ore was processed elsewhere.

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 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 along a small vein, termed the Blue Lead Extension (BD003). After disappointing results, the work 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). Subsequently, from 1939 to 1941, approximately 1,300 feet of surface and subsurface workings were completed at the Grey Lead mine (Thomas, 1970). Over 300 feet of the surface expression of the vein was traced (Joesting, 1938). There has been limited exploration reported in the 1970's. The mine shaft opening is accessible, but blocked by ice (Thomas, 1970).

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-99 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.