Unnamed (east of head of Bonanza Creek)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Pb; Zn
Other commodities As
Ore minerals galena; sphalerite
Gangue minerals ankerite; quartz; siderite

Geographic location

Quadrangle map, 1:250,000-scale WI
Quadrangle map, 1:63,360-scale C-2
Latitude 67.558
Longitude -150.8153
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is about 2 miles south-southeast of the small lake at the head of Bonanza Creek. It is on the west slope of the ridge between Bonanza and Conglomerate Creeks, about 0.5 mile west-northwest of the center of section 25, T. 32 N., R. 15 W., of the Fairbanks Meridian. The location is accurate.

Geologic setting

Geologic description

Brosge and Reiser (1960) originally describe this occurrence as a galena-bearing quartz vein in Middle(?) Devonian slate, phyllite and siltstone. Kurtak and others (2002) describe a 35-foot-wide by 150-foot-long area of rusty-weathering, intensely fractured and dolomitized metamorphic rock that they tentatively interpret as a northwest-trending shear zone. The rock is cut by numerous quartz veinlets containing traces of galena, sphalerite, and possibly ankerite(?). A sample of quartz float with traces of galena and sphalerite contained 3,510 parts per million (ppm) zinc, 3,438 ppm lead, and 3,772 ppm arsenic.
Geologic map unit (-150.818056003141, 67.5575640002647)
Mineral deposit model Quartz vein? with minor galena and sphalerite.
Age of mineralization Devonian or younger based on the age of the host rock.
Alteration of deposit Rusty weathering, intense fracturing, and dolomitization.

Production and reserves

Workings or exploration Only surface sampling by the U.S. Geological Survey and the Bureau of Land Management (Brosge and Reiser, 1960; Kurtak and others, 2002).
Indication of production None
Reserve estimates None.
Production notes None.

Additional comments

This occurrence is the Gates of the Arctic National Park.


MRDS Number A011953


Reporters J.M. Britton (Anchorage); D.J. Grybeck (Contractor, USGS)
Last report date 2/1/2011