Unnamed (claims on lower Granite Creek, Mt. Eielson district)

Prospects, Inactive

Commodities and mineralogy

Main commodities Pb; Zn
Other commodities Ag; Cu
Ore minerals chalcopyrite; galena; pyrite; sphalerite
Gangue minerals epidote; quartz

Geographic location

Quadrangle map, 1:250,000-scale MM
Quadrangle map, 1:63,360-scale B-1
Latitude 63.3997
Longitude -150.3028
Nearby scientific data Find additional scientific data near this location
Location and accuracy The MacKenzie and Mary claims abut each other in lower Granite Creek north of Mt. Eielson. The location is the approximate center of the end line between the claims. This location is at an elevation of about 4000 feet in the SW1/4NE1/4 sec. 31, T. 17 S., R. 14 W., Fairbanks Meridian. The location is accurate to about 500 feet.

Geologic setting

Geologic description

The McKenzie and Mary claims are in lower Granite Creek and are mainly covered by talus and alluvial fan deposits. South of the McKenzie claim, pyrite and chalcopyrite are disseminated in altered sedimentary rock cut by Eocene or Oligocene, fine-grained granodiorite and porphyritic granodiorite (Reed,1933, p. 283; Decker and Gilbert, 1978; Reed and Lanphere, 1974, and Cole, 1998). On the east part of the Mary claim, sulfide-bearing rock is exposed in two pits. At one pit, mineralized strata strike about N. 75 E. and dip about 75 N. Epidotized sedimentary rock exposed in an eight-foot-high face contains sphalerite, galena, and chalcopyrite; a chip sample assayed 0.3 ounce of silver per ton, 0.2 percent copper, and 2.31 percent zinc. At the other pit, the rocks are appreciably copper stained (Reed, 1933, p. 283). The mineralization is probably Oligocene, roughly contemporaneous with the emplacement age of the granodiorite.
Geologic map unit (-150.305054839478, 63.3992077637003)
Mineral deposit model Polymetallic replacement deposits; Pb-Zn skarn (Cox and Singer, 1986; models 19a; 18c).
Mineral deposit model number 19a; 18c
Age of mineralization The mineralization is probably Oligocene, roughly contemporaneous with the Eocene or Oligocene emplacement age of the granodiorite (Reed and Lanphere, 1974; Decker and Gilbert, 1978; Cole, 1998).
Alteration of deposit Introduction of epidote and silica into metasedimentary rocks. Local oxidation of copper minerals.

Production and reserves

Workings or exploration The McKenzie and Mary claims were owned by prospector Hugh Matheson at the time of Reed's study in 1931 (Reed, 1933). The claims lapsed and were later restaked as the Lead No. 1 and Lead No. 2 (Muir, Thomas, and Sanford, 1947). The claims were prospected with shallow pits.
Indication of production None

Additional comments

The claims are in Denali National Park and Preserve.

References

References

Reporters C.C. Hawley
Last report date 12/15/2000