PG

Occurrence, Active

Commodities and mineralogy

Main commodities Ag; Au; Cu; Pb; Zn
Ore minerals chalcopyrite; galena; gold; sphalerite

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale B-1
Latitude 63.3357
Longitude -144.4437
Nearby scientific data Find additional scientific data near this location
Location and accuracy The PG occurrence is in moraine debris at the toe of the glacier and about 1.6 miles west of peak 7886 in the SW1/4 section 15, T. 18 N., R. 5 E., Copper River Meridian. The location is accurate.

Geologic setting

Geologic description

The PG prospect is a widespread occurrence of massive sulfide float in moraine of an unnamed glacier. The probable source of the float is the Drum unit of felsic metavolcanic rocks that are exposed along the southern edge of the glacier. The unit dips approximately 20 degrees to the southeast; it is overlain by the Tok River unit and underlain by the Tiger unit. The glacier has receded significantly in recent years and has uncovered more massive sulfide float. A 5,000-foot-long train of massive sulfide float has been traced on the ice along the south edge of the glacier. Float samples average 0.8 percent copper, 1.1 percent lead, 2.0 percent zinc, 1.5 ounces of silver per ton, and 1,750 parts per billion (ppb) gold. A sample taken at the head of the float train assayed 0.1 percent copper, 6.6 percent lead, 8.4 percent zinc, 1.5 ounces of silver per ton, and 170 ppb gold (E. Hunter, unpublished data, 1998). About 1.5 miles to the southeast, the Drum mineralized layer is exposed at the PGX prospect (MH260) (E. Hunter, unpublished data, 1998).
Geologic map unit (-144.445949814882, 63.3353222297811)
Mineral deposit model Kuroko massive sulfide (Cox and Singer, 1986; model 28a).
Mineral deposit model number 28a
Age of mineralization The Drum unit, which is part of the metamorphic sequence that includes the rocks at this deposit, has been dated at the Devonian-Mississippian boundary on the basis of one SHRIMP U-Pb zircon age of 359 +/- 6 Ma at the nearby DD South prospect (MH325) (Dashevsky and others, 2003).

Production and reserves

Workings or exploration A 5,000-foot-long train of massive sulfide float has been traced on the ice along the south edge of the glacier, but only limited surface sampling has been completed.
Indication of production None

Additional comments

Unpublished data cited is available for viewing by contacting Grade Resources Inc. in Vancouver, B. C., Canada (www.grayd.com), or Northern Associates Inc. in Fairbanks, Alaska.

References