Lone Jack

Prospect, Probably inactive

Commodities and mineralogy

Main commodities Ag; Au; Cu
Ore minerals chalcopyrite; pyrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale CR
Quadrangle map, 1:63,360-scale C-3
Latitude 55.56339
Longitude -132.67889
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Lone Jack prospect is at an elevation of about 400 feet, about 1.2 mile east-southeast of the mouth of McGilvery Creek on Salmon Lake. It is just north of the center of the southern boundary of section 5, T. 73 S., R. 84 E.

Geologic setting

Geologic description

The Lone Jack prospect has a tunnel at an elevation of about 400 feet; large quartz boulders are on the dump (Roehm, 1938 [PE 119-8]. Between about 300 and 400 feet elevation, 2 parallel quartz veins in diorite are exposed for about 500 feet along a creek. Large masses of pyrite are scattered in the veins. Assays showed less than $1 per ton each in gold and silver. Maas and others (1995) collected several samples of quartz with minor pyrite and chalcopyrite that contained 20 to 1,850 parts per billion gold, 0.4 to 10.8 parts per million (ppm) silver, and 30 to 2,516 ppm copper.
The rocks in the vicinity of this prospect are part of a large granodiorite-quartz diorite stock (Sainsbury, 1961; Eberlein and others, 1983; Brew, 1996). Early workers considered the stock to be Mesozoic or Cretaceous, but recent radiometric dating indicates that it is Devonian (S.M. Karl, oral communication, 2003).
Geologic map unit (-132.680541157897, 55.5630272492372)
Mineral deposit model Polymetallic vein (Cox and Singer, 1986; model 22c).
Mineral deposit model number 22c
Age of mineralization Unknown, other than that the veins are in Devonian granitic rocks.

Production and reserves

Workings or exploration At least one short adit.
Indication of production None

Additional comments

This prospect is in the Karta River Wilderness Area, which is closed to exploration and mining.