Unnamed (northeast shoulder of Swinging Dome)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Sb; Sn
Other commodities As; B
Ore minerals unspecified sulfides
Gangue minerals quartz; tourmaline

Geographic location

Quadrangle map, 1:250,000-scale ID
Quadrangle map, 1:63,360-scale B-5
Latitude 62.33896
Longitude -158.25184
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 850 feet on the northeast slope of Swinging Dome about 0.8 mile northeast of its summit. The occurrence is about 0.3 mile south-southwest of the center of section 18, T. 26 N., R. 48 W., Seward Meridian. The location is accurate.

Geologic setting

Geologic description

This occurrence is a sulfide and tourmaline-bearing silicified zone at the contact between a Tertiary intrusive body and hornfels derived from the Upper Cretaceous, Kuskokwim Group (Miller and Bundtzen, 1994; Bundtzen and others, 1992; Bundtzen and Miller, 1997; Miller, Bundtzen, and Gray, 2005). The Swinging Dome intrusive is 60.9 Ma. Disseminated sulfides locally make up to 10 percent of the silicified zones. Several felsic dikes intrude the contact zone. One grab sample of mineralization contained 20 parts per million (ppm) tin, 20 ppm antimony, 40 ppm arsenic, and 2,000 ppm boron (McGimsey and others, 1988; Bundtzen and others, 1992).
Geologic map unit (-158.2542525095, 62.3382744740611)
Mineral deposit model Possibly Sn-polymetallic deposit model or Polymetallic vein (Cox and Singer, 1986; model 20b or 22c).
Mineral deposit model number 20b or 22c
Age of mineralization Unknown; the Swinging Dome intrusion that may be related to the deposit is 60.9 Ma (Miller and Bundtzen, 1994).
Alteration of deposit Tourmaline and silicification in contact zone.

Production and reserves

Workings or exploration Samples were collected by the U.S. Geological Survey and Alaska Division of Geological and Geophysical Surveys in the 1980s (McGimsey and others, 1988; Bundtzen and others, 1992).
Indication of production None



Reporters T.K. Bundtzen (Pacific Rim Geological Consulting, Inc.), M.L. Miller (U.S. Geological Survey); and C.C. Hawley (Hawley Resource Group)
Last report date 5/24/2003