See also Buzz (WI047).
Location: The Ann prospect is located 3.5 miles east-northeast of the east end of Ernie Lake and about 3.5 miles northwest of the junction of Pass Creek and Mettenpherg Creek. The coordinates mark the principle mineral showing; it is on an unnamed creek at an elevation of about 580 meters, just east of the center of section 26, T. 30 N., R. 24 W., of the Fairbanks Meridian. There are other mineral showings in the vicinity; most are up to 500 feet upstream and downstream from the main showing. The location is accurate.
Geology: This occurrence consists of vein and stratabound(?) Pb-Zn deposits that consist of massive, stringer, and disseminated sulfides in pelitic schist interbeds in the Devonian, Skajit Limestone, adjacent to the Ernie Lake granitic plutons (Nokleberg and others, 1996). The principal mineral showing at the Ann prospect is a steeply-dipping lens of massive pyrite, sphalerite, galena and minor chalcopyrite between graphitic quartz schist and sericite-talc schist (Kurtak and others, 1999). The lens is 4-5 feet thick and is exposed for only about 6 to 7 feet before pinching out in one direction and disappearing under cover in the other. A chip sample across this lens contains 3.34% lead, 4.31% zinc, 2.64 ounces of silver per ton, and 2,478 ppb gold (Kurtak and others, 1999). Bedded quartz-barite rock occurs a few hundred feet from the main Pb-Zn showing, but it contains no sulfides. Several similar, but smaller, deposits are within a few hundred feet of the main showing. One of these deposits consists of pyrite, arsenopyrite, pyrrhotite(?), galena, and chalcopyrite in layers and veins in calcareous, quartz-mica schist near the contact of granite gneiss and marble. A sample contains 37.7 ppm silver, 13% arsenic, 3.8% lead, 1.8% zinc, 315 ppm antimony (Dillon and others, 1981; sample 480 [AOF 133B]). Secondary copper carbonates--malachite and azurite--occur in the marble, calc-schist, and pelitic schist layers. Claims were staked in 1975 (Grybeck, 1977). Exploration included surface rock sampling, geologic mapping, geochemical soil sampling, hand trenching, and ground geophysics. There was also limited surface rock sampling by government agencies in 1980's and 1990's (Dillon and others, 1981 [AOF 133B]; Kurtak and others, 1999).
Workings: Claims were staked in 1975 (Grybeck, 1977). Exploration included surface rock sampling, geologic mapping, geochemical soil sampling, hand trenching, and ground geophysics. There was also limited surface rock sampling by government agencies in 1980's and 1990's (Dillon and others, 1981 [AOF 133B] Kurtak and others, 1999).
Alteration: Oxidation of copper mineral(s).

Commodities (Major) - Ag, Cu, Pb, Zn; (Minor) - Au
Development Status: None
Deposit Model: Polymetallic vein (metamorphosed) (Cox and Singer, 1986; model 22c) or Metamorp

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Standard Detailed Gallery Strunz Chemical Elements

Commodity List

This is a list of exploitable or exploited mineral commodities recorded at this locality.

Mineral List

10 valid minerals.