Unnamed (ridge at head of Spruce Creek)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Ag
Other commodities Au; Pb; Zn
Ore minerals galena; pyrite; sphalerite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale MM
Quadrangle map, 1:63,360-scale C-2
Latitude 63.5792
Longitude -150.7248
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 4200 feet at the head of Spruce Creek. It is about 0.7 mile southwest of Spruce Peak. The location is accurate within 250 feet. The occurrence is approximately the same as that of sample locality 244 of Hawley and Associates (1978).

Geologic setting

Geologic description

The country rocks near this occurrence are metafelsite and chloritic phyllite of the lower Paleozoic Spruce Creek sequence (Bundtzen, 1981; Thornsberry, McKee, and Salisbury, 1984, fig. K-2). The deposit is a steeply-dipping quartz-sulfide vein that strikes about N50E and is 2 to 3 feet thick. The vein is largely oxidized, but contains pyrite. A sample of residual soil along the strike of the vein contained 0.47 ppm gold, 120 ppm silver, 675 ppm copper, 14500 ppm lead, and 21000 ppm zinc (Hawley and Associates, 1978, no. 244). The lead and zinc values indicate that the vein contains galena and sphalerite.
Geologic map unit (-150.727084248638, 63.5786988627047)
Mineral deposit model Polymetallic vein (Cox and Singer, 1986; model 22c).
Mineral deposit model number 22c
Age of mineralization The deposit is assumed to be Eocene (see record MM091).
Alteration of deposit Oxidation of sulfide minerals.

Production and reserves

Workings or exploration The vein may have been explored by small pits, since sloughed.
Indication of production None

Additional comments

The occurrence is in Denali National Park and Preserve.

References