Kamishak Prospect (Painted River), Redoubt Mining District, Kenai Peninsula Borough, Alaska, USAi

Regional Level Types
Kamishak Prospect (Painted River)	Prospect
Redoubt Mining District	Mining District
Kenai Peninsula Borough	Borough
Alaska	State
USA	Country

Most of the geologic description in this record is abstracted from logs of drill core stored at the Alaska Geologic Materials Center in Eagle River, Alaska (Alaska Geologic Materials Center, 1995).
Location: The Kamishak prospect is in the SE1/4 SE1/4 sec. 10, T. 11 S., R. 31 W. It is at an elevation of about 1,500 feet on the northwest wall of a southwest-trending canyon that continues into adjacent section 15 The location is accurate within 500 feet.
Geology: The Kamishak prospect is a breccia pipe at least 300 feet in diameter in Jurassic(?) intermediate and mafic igneous rocks (Detterman and Reed, 1980; Alaska Geologic Materials Center, 1995; P. Thurston, written commun., 2003). The strongest mineralization in the pipe is near its walls, and consists of angular blocks of intensely sericitized, fine- to medium- grained gabbro in a matrix of coarse amphibole, biotite, and plagioclase, and 1 to more than 5 percent sulfides. Weaker mineralization occurs in less-brecciated to massive gabbro and diorite containing irregular clots of amphibole, biotite, chlorite, and sulfides. Minor phases of the breccia include hornblende gabbro and gabbroic anorthosite; the anorthosite locally contains a few percent of disseminated magnetite. The sulfide minerals are chiefly pyrite and chalcopyrite; bornite locally makes up as much 5 percent of the breccia. Malachite coats joint faces of mineralized rock, and magnetite occurs in amounts up to about 3 percent. Samples of the breccia locally contain significant gold and copper, and up to about 0.3 ounce of silver per ton. American Copper and Nickel Company (ACNC) drilled the deposit in 1990 and 1991 for a total of 5,300 feet (Alaska Geologic Materials Center, 1995). In drill hole 83523, the interval between 166 and 235 feet contained as much as 1,990 parts per billion gold and 2.58 percent copper; none of the interval contained less than 102 parts per billion gold and 0.255 percent copper. The interval from 15 to 166 feet also is mineralized. Drill holes 83521 and 83524 through 83527 are also appreciably mineralized. Alteration minerals in the breccia include chlorite, biotite, potassium feldspar, and sericite. Relatively high gold values appear to accompany coarse secondary biotite and do not necessarily correlate with copper content. Full Metal Minerals and Andover Ventures drilled 5 holes on this prospect in 2006 that totaled 750 meters (Andover Resources, 2008 (Kamishak), Andover Resources, 2008 (North Breccia)). Three of the 5 holes cut mineralization. Notable intercepts were: 1) 73.5 meters that contained 0.31 percent copper and 0.28 gram of gold per ton, 2) 51.0 meters that contained 0.48 percent copper and 0.46 gram of gold per ton, and 3) 7.50 meters that contained 0.36 percent copper and 0.53 gram of gold per ton. Two areas of mineralized breccia were identified. The westernmost breccia is a pipelike body about 30 by 50 meters in size; it is cut by a narrow fault zone with malachite and by thin sulfide- and magnetite-rich veins. The other breccia is a mineralized, pipelike body about 75 by 150 meters in size that extends to a depth of at least 75 meters. It has disseminated copper minerals as well as sulfide-bearing veinlets. This breccia locally contains abundant biotite, is strongly silicified, and also has sericite-pyrite, and chlorite alteration.
Workings: The prospect was discovered by Andy Snyder of the Spokane office of American Copper and Nickel Company (P. Thurston, written commun., 2003). The company core drilled 18 holes in 1990 and 1991 for a total of 5,300 feet. Full Metal Minerals and Andover Ventures drilled 5 holes on this prospect in 2006 that totaled 750 meters (Andover Resources, 2008 (Kamishak), 2008b).
Age: Jurassic?
Alteration: Propylitic and potassic: development of secondary biotite and potassium feldspar; local sericitization.
Reserves: None.

Commodities (Major) - Au, Cu; (Minor) - Ag, Fe
Development Status: None
Deposit Model: Porphyry copper-gold(?) (Cox and Singer, 1986; model 20c).

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Link to USGS - Alaska:	IL047

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References