McCullough

Prospect, Inactive

Alternative names

Lake Bay

Commodities and mineralogy

Main commodities Cu
Other commodities Ag; Au
Ore minerals chalcopyrite; pyrite; sphalerite
Gangue minerals calcite; quartz

Geographic location

Quadrangle map, 1:250,000-scale CR
Quadrangle map, 1:63,360-scale D-3
Latitude 55.97678
Longitude -133.00197
Nearby scientific data Find additional scientific data near this location
Location and accuracy The McCullough Mine is about 1.2 miles west of the mouth of Galligan Creek on Gold and Galligan Lagoon; it is about 0.4 mile northwest of the center of section 14, T. 68 S., R. 80 E. The location is accurate. A map of the area and the workings of the mine are shown on figure 71 of Maas and others (1995).

Geologic setting

Geologic description

The rocks in the vicinity of the McCullough Mine are mainly graywacke and argillite of the Silurian and Ordovician, Descon Formation (Eberlein and others, 1983; Brew, 1996) The deposit consists of a breccia vein 10 to 15 feet wide that is exposed in workings for about 300 feet (Maas and others, 1995). The vein consists of fragments of graywacke and argillite with pyrite, chalcopyrite, and sphalerite, in a quartz-calcite gangue. The vein has been sampled several times; the copper content typically is 1 to 3 percent (Townsend, 1945, 1946; Herbert and Race, 1965; Maas and others, 1995). Most older analyses show little or no gold, but a recent sample of high-grade material contained 4.39 percent copper, 68 parts per billion (ppb) gold, and 11.9 parts per million silver. A continuous chip sample across 0.9 meter of the vein contained 120 ppb gold (Maas and others, 1995).
The deposit was discovered in 1903 and a 4-ton test sample that contained about 5 percent copper was shipped in 1905 and 1906 (Roppel, 1991) . The workings consist of two shafts, one 71 feet deep, and numerous cuts along the vein. There was intermittent work until 1922 but there was no production. The deposit was restaked in 1929 and the workings were extended from the bottom of the 71-foot shaft. The deposit was examined by Harry Townsend in 1945 for the Anaconda Copper Mining Company. He did some limited exploration trenching and sampling but Anaconda did not acquire the property.
Geologic map unit (-133.003675986479, 55.9764148875898)
Age of mineralization The vein is younger than the Silurian or Ordovician sedimentary host rocks.

Production and reserves

Workings or exploration The deposit was discovered in 1903 and a 4-ton test sample that contained about 5 percent copper was shipped in 1905 and 1906 (Roppel, 1991). The workings consist of two shafts, one 71 feet deep, and numerous cuts along the vein. There was intermittent work until 1922 but apparently no production. The deposit was restaked in 1929 and the workings were extended from the bottom of the 71-foot shaft. The deposit was examined by Harry Townsend in 1945 for the Anaconda Copper Mining Company. He did some limited exploration trenching and sampling but Anaconda did not acquire the property.
Indication of production Yes; small
Reserve estimates None.
Production notes Only a 4-ton test shipment in 1905 and 1906.

References

MRDS Number A010002

References

Roppel, Patricia, 1991, Fortunes from the earth: Manhattan, Kansas, Sunflower University Press, 139 p.
Townsend, Harry, 1945, Preliminary report, Lake Bay copper prospect, Prince of Wales Island: Anaconda Copper Mining Company, 5 p. (Unpublished report held as file 6357, Anaconda Collection, American Heritage Center, University of Wyoming, Laramie.)
Townsend, Harry, 1946, Supplemental report, Lake Bay copper prospect, Prince of Wales Island: Anaconda Copper Mining Company, 4 p. (Unpublished report held as file 6357, Anaconda Collection, American Heritage Center, University of Wyoming, Laramie.)
Reporters D.J. Grybeck (Applied Geology)
Last report date 5/1/2004