Prospect, Active?

Commodities and mineralogy

Main commodities Au
Other commodities Ag; Hg; Sb; W
Ore minerals arsenopyrite; chalcopyrite; gold; pyrite; pyrrhotite; stibnite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale GO
Quadrangle map, 1:63,360-scale B-7
Latitude 59.3448
Longitude -161.3346
Nearby scientific data Find additional scientific data near this location
Location and accuracy This lode prospect is on the ridge crest that makes up the divide between the headwaters of Wattamuse Creek (GO021), Granite Creek, and South Fork Arolik River. It is on the saddle about 1,000 feet east of a 1,813-foot summit, and 0.6 mile due north of Granite Creek. It is accurately located.

Geologic setting

Geologic description

An Upper Cretaceous granodiorite-diorite stock underlies the head of Granite and Wattamuse Creeks (Hoare and Coonrad, 1978). This stock hosts 1 inch- to 1-foot-thick quartz veins containing arsenopyrite, stibnite, pyrite, and some chalcopyrite (Calista Corp. 2008). A soil-geochemical grid over about a 1/4- by 1/2-mile area straddling the ridge crest showed large areas of soil containing more than 100 parts per billion (ppb) gold, and several areas containing more than 1,000 ppb gold. Individual grab samples collected for Calista Corporation contain up to 9.5 parts per million (ppm) gold, 14.9 ppm silver, 17 percent arsenic, 22 percent antimony, and 1,500 ppm mercury (Fechner, 1988, p. 58). The U. S. Bureau of Mines collected 19 grab samples of rocks in the headwaters of Wattamuse Creek. One of these, a composite grab sample collected in this prospect area, assayed 2.18 ounces of gold per ton, 6.6 ppm silver, 2,850 ppm arsenic, 400 ppm bismuth, 40 ppm antimony, and 184 ppm tungsten (Fechner, 1988). Grab samples of quartz veins contained 1.25 to 5.3 ppm Au. The country rocks around the granitic stock locally include mafic rocks; a sample of mafic rock containing arsenopyrite, pyrrhotite, and chalcopyrite assayed 17.4 ppm silver, 3.3 ppm gold, 0.13 percent arsenic, 30 ppm bismuth, and 0.19 percent copper (Fechner, 1988, p. 58).
Geologic map unit (-161.336834945579, 59.3440277012856)
Mineral deposit model Granitic rock-hosted epithermal gold/silver.
Age of mineralization Late Cretaceous or younger. A K/Ar age of biotite from the host granitic stock is 71.3 +/- 2.1 Ma on biotite (Hoare and Coonrad, 1978).
Alteration of deposit Silicification.

Production and reserves

Workings or exploration A soil geochemistry grid, selected rock sampling, and probably surface mapping have been completed on the prospect (Calista Corp., 2008).
Indication of production None



Reporters Travis L. Hudson (Applied Geology); D.J. Grybeck (Port Ludlow, WA)
Last report date 3/4/2008