Senate

Prospect, Undetermined

Commodities and mineralogy

Main commodities Cu
Ore minerals chalcopyrite

Geographic location

Quadrangle map, 1:250,000-scale SI
Quadrangle map, 1:63,360-scale C-7
Latitude 57.7308
Longitude -136.2757
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Senate prospect is at an elevation of about 100 feet, 0.3 mile north of the south tip of Hill Island. The prospect is 0.2 mile northeast of the southwest corner of sec. 1, T. 48 S., R. 56 E. It is location P-53 of Bittenbender and others (1999) and MAS no. 0021140109 (U.S. Bureau of Land Management, 2002). The location probably is accurate within about 0.5 mile.

Geologic setting

Geologic description

Johnson and Karl (1985) map the rocks in the area of this prospect as hornfelsed, Cretaceous graywacke and argillite containing sparse, lenticular beds of recrystallized basalt ('greenstone'). The formation is cut by many steeply-dipping, mainly northwest-striking faults.
Bittenbender and others (1999), citing Still and Weir (1981), describe this prospect as a copper-bearing, volcanogenic massive sulfide deposit hosted in greenstone. They do not specify the ore mineral(s), but they probably include chalcopyrite, which occurs in similar deposits nearby (for example, SI075).
Geologic map unit (-136.27753016547, 57.7304276776157)
Mineral deposit model Volcanogenic massive sulfide deposit?
Age of mineralization If the prospect is a volcanogenic massive sulfide deposit, it probably is Cretaceous, the age of the greenstone host rock.

Production and reserves

Indication of production Undetermined

Additional comments

The prospect is in West Chichagof-Yakobi Wilderness.

References

References

Bittenbender, P., Still, J.C., Maas, K., and McDonald, M., Jr., 1999, Mineral resources of the Chichagof and Baranof Islands area, southeast Alaska: Bureau of Land Management, BLM-Alaska Technical Report 19, 222 p.
U.S. Bureau of Land Management, 2002, Alaska mineral locations database report (Sitka quadrangle), July 2, 2002, 205 p. [http://imcg.wr.usgs.gov/dem.html]
Reporters H.C. Berg (U.S. Geological Survey)
Last report date 10/16/2004