Kayak Island Occurrence, Yakataga Mining District, Valdez-Cordova Census Area, Alaska, USAi

Regional Level Types
Kayak Island Occurrence	Occurrence
Yakataga Mining District	Mining District
Valdez-Cordova Census Area	Census Area
Alaska	State
USA	Country

Location: This occurrence is near the mouth of a small creek on the east side of Kayak Island. The map site is at an elevation of about 100 feet, 2.2 miles southwest of Pyramid Peak, on the south boundary of section 6, T 23 S, R 6 E, of the Copper River Meridian. The occurrence is sample locality 021 of Goldfarb and others (1989), and it is accurately located.
Geology: This occurrence is representative of several localities on Kayak Island where stream sediments and heavy-mineral concentrates contain highly anomalous amounts of barium and zinc and less anomalous amounts of silver, copper, lead, molybdenum, and nickel (Goldfarb and others, 1989). At this locality, stream sediments contain 0.5 ppm silver, 150 ppm boron, 5,000 ppm barium, 20 ppm molybdenum, 150 ppm nickel, and weakly anomalous levels of cobalt, copper, scandium, and zinc. The heavy-mineral concentrates from these stream sediments contain 10,000 ppm strontium and 2,000 ppm zinc. Barite is abundant in heavy-mineral concentrates from stream sediments on Kayak Island, and it is generally accompanied by pyrite, sphalerite (zinc concentrations to 20,000 ppm), 10 to 30 percent iron, and 150 to 700 ppm nickel (Goldfarb and others, 1989; Pickthorn and others, 1985). Concentrates with anomalous copper and lead contain microscopic chalcopyite and galena. The barite and base metals are derived from weathering of Tertiary sandstone, siltstone, and glacial-marine deposits of the Poul Creek and Yakataga Formations (Plafker, 1974). The Eocene to Miocene Poul Creek Formation contains interbedded mafic pyroclastic and flow rocks in its upper part and is locally intruded by mafic dikes and sills. Soil sampling on Kayak Island suggests that many of the stream-sediment and heavy-mineral concentrate anomalies are spatially associated with the upper Poul Creek Formation, which contains mafic igneous rocks (Pickthorn and others, 1985).
Workings: A reconnaissance stream-sediment and heavy-mineral concentrate geochemical survey (Goldfarb and others, 1989) and follow-up soil geochemical survey (Pickthorn and others, 1985) have been completed on Kayak Island.
Age: Probably late Tertiary, the age of the upper Poul Creek and Yakataga Formations.

Commodities (Major) - Cu, Pb, Zn; (Minor) - Ag, Ba, Mo, Ni
Development Status: None
Deposit Model: Sedimentary-exhalative Zn-Pb ? (Cox and Singer, 1986; model 31a)

Other Databases

Link to USGS - Alaska:	MI002

Other Regions, Features and Areas containing this locality

References