|Quadrangle map, 1:250,000-scale||CR|
|Quadrangle map, 1:63,360-scale||A-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The Gonnason prospect is about 0.7 mile north-northwest of Copper Mountain and about 0.2 mile north-northwest of the southeast corner of section 27, T. 76 S., R. 84 E.|
Geologic descriptionThe Gonnason prospect was found in 1960 by the Hanna Mining Company (Hogg, 1965; Herreid and others, 1978). The deposit consists of a body of magnetite with chalcopyrite in skarn. As exposed on the surface, the body is about 150 by 225 feet in area and of unknown depth. A channel sample about 80 feet long across the deposit averaged 50.6 percent iron and 0.94 percent copper. Hogg (1965) estimated that the deposit is comparable in tonnage and grade to the Magnetite Cliff deposit (CR148). Although the body is in skarn, Kennedy (1953) and Herreid and others (1978) map the rocks in the area only as Cretaceous granodiorite. The deposit is probably in a small roof pendant of skarn in the granodiorite and is similar to the deposits at the nearby Jumbo Mine (CR150) and Magnetite Cliff (CR148).
|Geologic map unit||(-132.618296067923, 55.2456584748956)|
|Mineral deposit model||Iron-copper skarn (Cox and Singer, 1986; model 18d).|
|Mineral deposit model number||18d|
|Age of mineralization||Iron-copper skarn probably related to a nearby Cretaceous granodiorite intrusion.|
|Alteration of deposit||Associated with magnetite-bearing skarn.|
|Workings or exploration||Surface sampling and geophysical surveys.|
|Indication of production||None|
|Reserve estimates||Hogg (1965) estimated that the deposit is comparable in tonnage and grade to the Magnetite Cliff deposit (CR148).|
Additional commentsThe Gonnason prospect is on a large block of patented claims. The land around it has been conveyed to the Sealaska Corporation or is under application for transfer to them.
Herreid, Gordon, Bundtzen, T.K., and Turner, D.L., 1978, Geology and geochemistry of the Craig A-2 quadrangle, Prince of Wales Island, southeastern Alaska: Alaska Division of Geological and Geophysical Surveys Geologic Report 48, 49 p.
Hogg, N., 1965, Eskil Anderson properties-Jumbo Basin, Prince of Wales Island, Alaska: Unpublished report to Hanna Mining Company, 8 p. (Unpublished report held by the Bureau of Land Management, Mineral Information Center, Juneau, Alaska.)
|Reporters||D.J. Grybeck (Applied Geology)|
|Last report date||5/1/2004|