West Green

Prospect, Active

Commodities and mineralogy

Main commodities Ag; Au; Cu
Other commodities Fe
Ore minerals chalcopyrite; gold; molybdenite
Gangue minerals calcite; quartz

Geographic location

Quadrangle map, 1:250,000-scale GU
Quadrangle map, 1:63,360-scale D-1
Latitude 62.9248
Longitude -144.1185
Nearby scientific data Find additional scientific data near this location
Location and accuracy The West Green prospect is located about 15.8 miles north-northwest of Slana. It is about 6.6 miles northwest of VABM 6677 'Ahtell' and about 0.4 mile northeast from the center of section 8, T. 13 N., R. 7 E., of the Copper River Meridian. The location is accurate within 1/4 mile.

Geologic setting

Geologic description

The rocks in the area of the West Green prospect are diorite and quartz diorite of the Permian to Pennsylvania Ahtell pluton (Wilson and others, 1999). The rocks are cut by extensive dike swarms and faults. Mineralization is on the northeast side of a regional-scale northwest-striking fault (Corvus Gold Inc., 2012).
In 2011, Corvus identified the West Green prospect, where mineralization is in a typical copper porphyry style with high grade gold, through sampling and drilling (Corvus Gold Inc. 2012). Mineralization is centered on second order conjugate structures (Brown and others, 2012).
Over 0.5 percent copper grade follows potassic-propylitic alteration front with disseminated and veinlet chalcopyrite. Alteration is characterized as porphyry zoned alteration of potassic core with propylitic shell. Extensive quartz-calcite-chalcopyrite sheeted veins, stockwork veins, and vein breccias are present. Grab samples resulted in assay values of up to 10 parts per million (ppm) silver, 1 ppm molybdenum, and 0.6 percent copper (Brown and others, 2012).
Geologic map unit (, )
Mineral deposit model Porphyry Cu-Au (Cox and Singer, 1986; model 20c)
Mineral deposit model number 20c
Age of mineralization Younger than the Permian to Pennsylvanian host rocks (Wilson and others, 1998).
Alteration of deposit Porphyry zoned alteration of potassic core with propylitic shell. Over 0.5 percent copper grade follows potassic-propylitic alteration front with disseminated and veinlet chalcopyrite. Extensive quartz-calcite-chalcopyrite sheeted veins, stockwork veins, and vein breccias (Brown and others, 2012).

Production and reserves

Workings or exploration In 2011, Corvus Gold Inc. identified the West Green prospect, where mineralization is in a typical copper porphyry style, through sampling and drilling (Corvus Gold Inc. 2012). In 2010 to 2011, Corvus completed soil surveys of over 12 km in length. Results were over 10 gram per tonne gold over 12 km, and over 50 gram per tonne gold widespread. In 2011, a soil X-ray fluorescence (XRF) survey was executed. Corvus reported that mineralization is centered on second order conjugate structures (Brown and others, 2012).
Indication of production None
Reserve estimates None.
Production notes None.

References

References

Reporters V.C. Zinno (Alaska Earth Sciences, Inc.)
Last report date 5/30/2014