Unnamed (near Willow Creek)

Occurrence, Probably inactive

Commodities and mineralogy

Main commodities Au; Sb; Zn
Ore minerals gold; pyrite; pyrrhotite; sphalerite

Geographic location

Quadrangle map, 1:250,000-scale CH
Quadrangle map, 1:63,360-scale C-4
Latitude 67.6436
Longitude -148.8936
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 4,000 feet on a hillside about 1.6 mile east-southeast of the junction of Willow Creek and Little Spruce Creek. It is about 0.5 mile west of the center of section 34, T. 33 N., R. 6 W.

Geologic setting

Geologic description

Brosgé and Reiser (1972) collected samples with anomalous zinc in Devonian(?) albite-chlorite-mica schist near the contact with calcareous schist and marble (Brosgé and Reiser, 1964). Two of the rock samples contained 0.8 to 5.6 parts per million gold. There or nearby, Kurtak and others (2002) found knobs of resistant marble and hornfels in rubble crop of chlorite-muscovite schist. The hornfels contains a small amount of disseminated sphalerite, pyrite, and pyrrhotite. Six samples of hornfels contained 36 ppm to 3.09 percent zinc. A sample of hornfels in float contained 1.56 percent antimony and 153 parts per billion gold.
Geologic map unit (-148.896348930651, 67.6432044226888)
Mineral deposit model Hornfels with zinc, antimony, and gold.
Age of mineralization Devonian or younger based on the age of the host rock.
Alteration of deposit Masses of hornfels developed in chlorite-muscovite schist.

Production and reserves

Workings or exploration Only limited sampling by government agencies.
Indication of production None
Reserve estimates None.
Production notes None.

Additional comments

MAS No. 0020310074

References

References

Kurtak, J.M., Klieforth, R.F., Clark, J.M., and Maclean, E.A., 2002, Mineral investigations in the Koyukuk mining district, northern Alaska, 2 vols.: Bureau of Land Management, Alaska Technical Report 50, 845 p.
Reporters J.M. Britton (Anchorage, Alaska); D.J. Grybeck (Contractor, U.S. Geological Survey)
Last report date 4/18/2010