Treasure Creek

Prospect, Inactive

Commodities and mineralogy

Main commodities Cu; Mo
Other commodities Au; Zn
Ore minerals arsenopyrite; chalcopyrite; molybdenite; sphalerite
Gangue minerals clay; epidote; fluorite; quartz

Geographic location

Quadrangle map, 1:250,000-scale TK
Quadrangle map, 1:63,360-scale D-5
Latitude 62.8777
Longitude -149.2943
Nearby scientific data Find additional scientific data near this location
Location and accuracy Three mineralized sites are on or near Treasure Creek, a small informally named, east tributary of Portage Creek. The mouth of Treasure Creek is 4 miles upstream from the mouth of Portage Creek on the Susitna River The sites are within a mile of each other in an area centered in the NE1/4SE1/4 sec. 8, T. 32 N., R. 1 E., Seward Meridian. This is locality 9 of Csejtey and Miller, (1978).

Geologic setting

Geologic description

The three mineralized sites of the prospect have disseminated arsenopyrite, chalcopyrite, molybdenite, and sphalerite, quartz, fluorite, and epidote in a silicified and sheared Tertiary granite stock, and in argillite and metagraywacke intruded by the granite (Richter, 1963). There is local intense argillic alteration and limonite staining that extends irregularly up to 300 feet into the granite from a fault. The argillite and metagraywacke are part of an extensive Lower Cretaceous flysch unit. The stock is part of the lower Tertiary McKinley plutonic sequence. Samples of an arsenopyrite-rich boulder found on the surface contain 0.18 ounce of gold per ton, 2-3 percent zinc, 0.1-0.5 percent copper, and 0.1-0.5 percent molybdenum (Richter, 1963). Rock samples from one of the sites contain contain up to 1.0 percent molybdenum, 2.65 percent zinc, and 1.7 ounces of silver per ton (Kurtak and others, 1992).
This prospect was explored by minor surface workings and shallow drilling. A caved adit is 500 feet south of the creek, near the east boundary of section 8 at an elevation of about 1,400 feet. Silver Dome Mining Company staked the Molly 1 to 18 claims, the Caribou 1 to 59 claims, and the Cheechako Moose 1 to 21 claims.
Geologic map unit (-149.296562433004, 62.877219429238)
Mineral deposit model Porphyry Cu-Mo (Cox and Singer, 1986; model 21a)
Mineral deposit model number 21a
Age of mineralization In Early Tertiary rocks.
Alteration of deposit Silicification, argillic and epidote alteration, with iron staining.

Production and reserves

Workings or exploration This prospect was explored by minor surface workings and shallow drilling. A caved adit is 500 feet south of the creek, near the east boundary of section 8 at an elevation of about 1,400 feet. Rock sampling by the U.S. Geological Survey and U.S. Bureau of Mines (Richter, 1963; Kurtak and others, 1992). Silver Dome Mining Company staked the Molly 1 to 18 claims, the Caribou 1 to 59 claims, and the Cheechako Moose 1 to 21 claims.
Indication of production None

Additional comments

MAS/MILS number 20760005.

References

MRDS Number A012173

References

Reporters R.K. Rogers (U. S. Geological Survey contractor)
Last report date 9/26/2002