|Quadrangle map, 1:250,000-scale||CR|
|Quadrangle map, 1:63,360-scale||B-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The only published location for this old prospect is a small-scale map and the description by Brooks (1902). He places it about a half mile north of the shore of Polk Inlet at an elevation of about 300 feet. There is a small island on his map in section 25, T. 74 S., R. 85 E. that can be identified on the modern 1:63,360-scale topographic map. The prospect is north of the island, probably within 1/4 mile of the center of the W1/2 section 24, T. 74 S., R. 85 E.|
Geologic descriptionThe only description of this prospect is by Brooks (1902). The rocks in the vicinity include black, carbonaceous, pyritiferous slate that strikes N 60 W and dips 50 NE. The rocks are part of the Descon Formation of Silurian and Ordovician age (Eberlein and others, 1983; Brew, 1996). A small cut exposes a (quartz?) vein up to 4 inches thick in crumpled slate. The vein contains pyrite and less than $1 per ton in gold (at $20.67 per ounce).
|Geologic map unit||(-132.433100070391, 55.438978299471)|
|Mineral deposit model||Quartz? vein with low gold values.|
|Age of mineralization||Unknown, other than that the vein is in Silurian or Ordovician slate.|
|Alteration of deposit||Slate is crumpled near the vein.|
|Workings or exploration||Only a small cut.|
|Indication of production||None|
Additional commentsThe Sealaska Corporation holds the subsurface rights to the land in the vicinity of this old prospect.
Brew, D.A., 1996, Geologic map of the Craig, Dixon Entrance, and parts of the Ketchikan and Prince Rupert quadrangles, southeastern Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-2319, 53 p., 1 sheet, scale 1:250,000.
Brooks, A.H., 1902, Preliminary report on the Ketchikan mining district, Alaska, with an introductory sketch of the geology of southeastern Alaska: U.S. Geological Survey Professional Paper 1, 120 p.
Cobb, E. H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Craig quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-869, 262 p.
|Reporters||D.J. Grybeck (Applied Geology)|
|Last report date||5/1/2004|