Granite Creek

Prospect, Inactive

Commodities and mineralogy

Main commodities Au
Other commodities Zn
Ore minerals gold

Geographic location

Quadrangle map, 1:250,000-scale TK
Quadrangle map, 1:63,360-scale B-2
Latitude 62.2974
Longitude -147.8626
Nearby scientific data Find additional scientific data near this location
Location and accuracy This placer prospect extends for about 2 miles of Granite Creek above its mouth on the Oshetna River (Csejtey and Miller, 1978, location 57). The placer is centered on Granite Creek at an elevation of about 4,300 feet. The location is accurate to within 1/4 mile.

Geologic setting

Geologic description

Gold in Granite Creek occurs in Tertiary(?) alluvial gravel deposits. The prospect was discovered in 1914, when placer claims were located on lower Granite Creek. Enough gold was found to encourage further prospecting in 1918 (Chapin, 1918). The placer deposits overlie Tertiary volcanic rocks and Jurassic volcanic rocks, and sandstone and argillite of the Talkeetna Formation (Csejtey and others, 1978). A Jurassic intrusion crops out at the head of the creek. Quaternary glacial deposits are also present at the head of the creek. The stream valley is 50 to 250 feet wide and the alluvial gravel is up to 15 feet thick. Boulders are up to 10 feet in diameter. The creek gradient is 150 to 300 feet per mile. A U.S. Bureau of Mines sample of the gravel contains 0.0002 ounce of gold per cubic yard; other samples contain up to 329 parts per million zinc (Kurtak and others, 1992).
Geologic map unit (-147.864785400826, 62.2969306611224)
Mineral deposit model Placer Au (Cox and Singer, 1986; model 39a)
Mineral deposit model number 39a
Age of mineralization Tertiary(?) placer.

Production and reserves

Workings or exploration The prospect was discovered in 1914, when placer claims were located on lower Granite Creek. Enough gold was found to encourage further prospecting in 1918 (Chapin, 1918). Limited sampling by the U.S. Bureau of Mines (Kurtak and others, 1992).
Indication of production Undetermined
Reserve estimates An estimated 500,000 cubic yards of potentially auriferous alluvial material is present in the drainage but no estimate of grade has been made (Kurtak and others, 1992).
Production notes No production is known.

Additional comments

MAS/MILS number 20760020.

References

MRDS Number A012196

References

Reporters R.K. Rogers (U. S. Geological Survey contractor)
Last report date 10/2/2002