Unnamed (west of upper Tsisi Creek)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Ag; Cu
Other commodities Au; Hg
Ore minerals malachite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale TK
Quadrangle map, 1:63,360-scale C-3
Latitude 62.5808
Longitude -148.4262
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 6,200 feet, about 1.1 mile northwest of hill 5370 and about 0.6 mile south-southeast of the center of sec. 24, T. 29 N., R. 5 E. of the Seward Meridian. The location is accurate to within 1/4 mile.

Geologic setting

Geologic description

This occurrence consists of coxcomb, quartz veins that contain minor malachite, in a sill(?) of Triassic, Nikolai Greenstone. The veins are nearly vertical and trend northeasterly. Adjacent rocks include pale gray-green, schistose, tuffaceous chert(?) and medium gray, schistose, meta-igneous rock containing relict plagioclase phenocrysts (J. Schmidt, written communication, 2001). A U.S. Geological Survey rock sample contains 2,110 parts per million copper, 81 parts per million silver, 0.17 part per million mercury, and 0.2 part per million gold. (An ICP analysis by XRAL Laboratory of one sample showed 0.2 part per million gold, whereas a fire assay showed 0.046 part per million gold. The cause of the discrepancy is not known.)
Geologic map unit (-148.428420912551, 62.580326032978)
Mineral deposit model Basaltic copper (Cox and Singer, 1986; model 23)
Mineral deposit model number 23

Production and reserves

Workings or exploration Only surface sampling by U.S. Geological Survey (J. Schmidt, written communication, 2001).
Indication of production None

References