Unnamed (Karshner Creek Ridge)

Occurrence, Probably inactive

Commodities and mineralogy

Main commodities Pb; Zn
Other commodities Fe; Mn; U
Gangue minerals limonite

Geographic location

Quadrangle map, 1:250,000-scale TN
Quadrangle map, 1:63,360-scale A-2
Latitude 65.00849
Longitude -150.63276
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 550 feet, on a south-facing ridge on the east side of Karshner Creek and about 1,500 feet north of Karshner hot spring. The site is at Alaska Division of Geological and Geophysical Surveys (ADGGS) sample station 97SL229A (Liss and others, 1998), near the southeast corner of section 8, T. 2 N., R. 15 W., of the Fairbanks Meridian. The location is accurate within 500 feet.

Geologic setting

Geologic description

Bedrock in the area of this occurrence is mainly Lower Cretaceous sandstone, shale, and siltstone that has been hornfelsed by the Tertiary Hot Springs granite pluton (Reifenstuhl and others, 1998). The hornfels is black, dense rock that contains unoriented crystals or rosettes of muscovite, biotite, and, locally, andalusite. Felsic dikes associated with the Hot Springs granite pluton occur throughout the area.
Several samples (97RR168B, 97SL229A, and 97SL229B) of gossan and hornfelsed shale on a ridge just east of Karshner Creek contained one or more of the following maximum geochemical values: more than 15 percent iron, 40 parts per million (ppm) lanthanum, 1,795 ppm manganese, 548 ppm lead, 40 ppm uranium, and 1,130 ppm zinc (Liss and others, 1998). There is no record of lode exploration or mining at this site.
Geologic map unit (-150.63522436935, 65.0080000863478)
Mineral deposit model Possibly epithermal, polymetallic, or mesothermal veins related to the Tertiary Hot Springs granite pluton.

Production and reserves

Workings or exploration Several samples (97RR168B, 97SL229A, and 97SL229B) of gossan and hornfelsed shale on a ridge just east of Karshner Creek contained one or more of the following maximum geochemical values: more than 15 percent iron, 40 parts per million (ppm) lanthanum, 1,795 ppm manganese, 548 ppm lead, 40 ppm uranium, and 1,130 ppm zinc (Liss and others, 1998). There is no record of lode exploration or mining at this site.
Indication of production None

References