Unnamed skarn, near Lime Peak (Rocky Mountain)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Sn
Other commodities Ag; U; W; Zn
Ore minerals pyrrhotite; scheelite; unknown sn mineral

Geographic location

Quadrangle map, 1:250,000-scale CI
Quadrangle map, 1:63,360-scale C-6
Latitude 65.628
Longitude -146.653
Nearby scientific data Find additional scientific data near this location
Location and accuracy The location is the site of samples of skarn and greisen taken by Burton and others (1985). Lime Peak, also known more recently as 'Rocky Mountain,' is approximately 58 miles northeast of Fairbanks in the White Mountains. There is no road access to the area. The Steese Highway is 30 miles to the southeast and existing winter trails extend from it into the area.

Geologic setting

Geologic description

Anomalous metal concentrations in rock samples collected from the Lime Peak area are associated with two styles of mineralization: skarn, developed near the contact zone of the Lime Peak pluton; and greisen, developed within the Lime Peak pluton (Burton and others, 1985, p. 15). Samples of skarn, collected from near the northern and southeastern intrusive contacts contain elevated to anomalous concentrations of tin and tungsten. The highest values were detected in iron-stained, magnetite-pyrrhotite-pyroxene skarn rubble, with one sample containing 220 ppm Sn and 100 ppm W (Burton and others, 1985, p. 15). Smith and others (1987), analyzed bulk samples of calc-silicate rocks in this area with resulting grades of 0.003 to 0.03 oz/ton Sn, 0.03 to 0.1 oz/ton Ag, 0.01 to 0.03 percent Cu, and 0.03 to 0.8 percent Zn. Because of the low abundance of carbonate rocks in the area and the considerable distance from known mineralizing granite units, Smith and others (1987) conclude that the Lime Peak area skarns/calc-silicate rocks are not of current or likely future economic interest.
Geologic map unit (-146.65550306484, 65.6276037985699)
Mineral deposit model Sn skarn and Sn greisen (Cox and Singer, 1986; model 14b and 15c)
Mineral deposit model number 14b and 15c
Age of mineralization Mineralization is related to Tertiary and/or Upper Cretaceous granitic plutons.
Alteration of deposit Fe-rich skarn.

Production and reserves

Workings or exploration Surface samples taken.
Indication of production None