|Quadrangle map, 1:250,000-scale||CR|
|Quadrangle map, 1:63,360-scale||B-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The only primary description of this prospect is by Brooks (1902), who locates it about a mile north of Grindall Point and about 0.3 mile west of the center of section 11, T. 74 S., R. 87 E. The 1993 edition of the USGS 1:63,360-scale topographic map shows an unnamed prospect at this location.|
Geologic descriptionThis old prospect consists of a quartz vein about 12 inches thick at the surface that thickens to 3 feet thick at the bottom of an open cut about 10 feet deep (Brooks, 1902). The vein is in sheared diorite with epidote along the shear zones. The vein strikes east and dips 70N. It contains chalcopyrite; a random sample assayed 0.41 ounce of silver per ton and 0.14 ounce of gold per ton. The south end of the Kasaan Peninsula consists of a large pluton of Silurian or Ordovician diorite (Eberlein and others, 1983; Brew, 1996).
|Geologic map unit||(-132.156080622199, 55.4667102666381)|
|Alteration of deposit||Shear zones in diorite adjacent to vein have coatings of epidote.|
|Workings or exploration||Explored by a 10-foot-deep open cut.|
|Indication of production||None|
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.
Eberlein, G.D., Churkin, Michael, Jr., Carter, Claire, Berg, H.C., and Ovenshine, A. T., 1983, Geology of the Craig quadrangle, Alaska: U.S. Geological Survey Open-File Report 83-91, 52 p.
|Reporters||D.J. Grybeck (Applied Geology)|
|Last report date||5/1/2004|