Unnamed (upper west headwaters of the Maclaren River)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu
Other commodities Ag
Ore minerals bornite; chalcocite; malachite
Gangue minerals epidote; quartz

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale A-6
Latitude 63.217
Longitude -146.6829
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 4,600 feet in the headwaters of a west tributary of the Maclaren River. The occurrence is in the NW1/4NW1/4 section 6, T. 20 S., R. 6 E., Fairbanks Meridian. The occurrence corresponds to locality 19 in figure 4 of Cobb (1979 [OFR 79-238]) and to locality 27 in table 2 of Nokleberg and others (1991).

Geologic setting

Geologic description

The rock at this occurrence is propylitized metabasalt of the Nikolai Greenstone of Late Triassic age (Nokleberg and others, 1991). The deposit consists of bornite, chalcocite, and malachite in quartz-epidote veinlets, in vesicles, and on fracture or joint surfaces in metabasalt (Saunders, 1961 [report for the year]; Smith and others, 1973). No assays are available, but small quantities of silver commonly occur in copper deposits in the Nikolai Greenstone.
Geologic map unit (-146.685164294023, 63.2165639587603)
Mineral deposit model Basaltic Cu (Cox and Singer, 1986; model 23).
Mineral deposit model number 23
Age of mineralization The deposit is probably Cretaceous or early Tertiary in age (see MH060 and MH100).
Alteration of deposit Propylitic alteration of basalt.

Production and reserves

Workings or exploration The deposit was found during regional mapping and sampling; there are no workings.
Indication of production None