Jarosa Ridge

Prospect, Inactive

Commodities and mineralogy

Main commodities Au
Other commodities As; Sb
Ore minerals arsenopyrite; gold; stibnite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale NM
Quadrangle map, 1:63,360-scale C-1
Latitude 64.7055
Longitude -165.4853
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is at an elevation of about 1,150 feet on the ridge crest trending west from Jarosa Creek valley. Jarosa Creek is a north tributary to Bangor Creek. The map location is in the SW1/4 section 16, T. 9 S., R. 34 W., Kateel River Meridian. The location is accurate to within about 500 feet.

Geologic setting

Geologic description

This is an old prospect that has apparently not been previously reported. Workings consist of at least six prospect pits or shallow shafts. A local soil geochemical survey in the 1990s found as much as 990 ppb gold, greater than 10,000 ppm arsenic, and as much as 63 ppm antimony (Kennecott Exploration Company, written communication, 1992). Bedrock in this area was mapped as calc- and chlorite-rich metaturbidite schist by Bundtzen and others (1994).
Geologic map unit (-165.487914638123, 64.7047350920304)
Mineral deposit model Possibly low sulfide, Au-quartz veins (Cox and Singer, 1986; model 36a).
Mineral deposit model number 36a?
Age of mineralization Not known; probably mid-Cretaceous or younger, similar to other gold lodes near Nome.
Alteration of deposit Silicification.

Production and reserves

Workings or exploration Six shallow shafts or prospect pits were dug before 1918, probably during the same period as prospecting near Twin Mountains Creek (Mertie, 1918 [B 662-I, p. 425-449]). The area was mapped and a local soil geochemical survey completed by Kennecott Exploration Company in 1991.
Indication of production None

References