Prospect, Probably inactive

Commodities and mineralogy

Main commodities Ag; Au; Cu; Pb; Zn
Other commodities Ba
Ore minerals arsenopyrite; bornite; chalcopyrite; enargite; galena; pyrite; pyrrhotite; sphalerite; tennantite
Gangue minerals barite; chlorite; ferroan calcite; ferroan dolomite; quartz

Geographic location

Quadrangle map, 1:250,000-scale SP
Quadrangle map, 1:63,360-scale A-5
Latitude 67.074
Longitude -155.225
Nearby scientific data Find additional scientific data near this location
Location and accuracy The STU prospect is located 0.1 mile east-southeast from the center of section 6, T. 19 N., R. 17 E., of the Kateel River Meridian. The prospect is located at approximately 900 feet elevation. This location is accurate to within 500 feet.

Geologic setting

Geologic description

The STU prospect is located about 8 kilometers west of the Sun project (SP039). The prospect is characterized by volcanogenic massive-sulfide mineralization. The property is located at the eastern end of the Ambler district. The massive sulfides are comprised primarily of sphalerite, tennantite, galena, chalcopyrite, bornite, enargite, pyrite, pyrrhotite, and arsenopyrite. Mineralization occurs in a northeast-trending belt of felsic metavolcanic and metasedimentary rocks. Massive-sulfide mineralization is primarily hosted within the felsic schist (Dsf) and sparsely porphyritic rhyolite (Dr) units of the Ambler Sequence. (Hitzman and others, 1982,Gustin and Ronning, 2013).
At STU, strong alteration and gossan have been mapped for approximately 100 meters along strike before disappearing beneath cover. There is extensive talus covering. Grab samples from the STU area returned values of up to 2.04 percent copper, 0.95 percent lead, 1.21 percent zinc, 64 grams of silver per tonne, and 0.49 grams of gold per tonne (Andover Mining Corporation, 2012).
Geologic map unit (, )
Mineral deposit model Kuroko massive sulfide (Cox and Singer, 1986; model 28a)
Mineral deposit model number 28a
Age of mineralization Devonian, based on age of host rock (Hitzman and others, 1982, Gustin and Ronning, 2013).
Alteration of deposit Iron oxide alteration (Andover Mining Corporation, 2012).

Production and reserves

Workings or exploration Exploration as consisted of field mapping and sampling of rock and soil, completed mostly during the mid 1970's through early 1980s. Andover completed one diamond core drillhole in 2012 at STU in addition to mapping and sampling. The drillhole included: 1) 8.1 meters of 0.49 percent copper, 0.71 percent lead, 2.75 percent zinc, 33.5 grams of silver per tonne, and 0.197 grams of gold per tonne (including 1.8 meters of 0.78 percent copper, 1.22 percent lead, 6.55 percent zinc, 81.4 grams of silver per tonne, and 0.478 grams of gold per tonne); and 2) 0.9 meters of 1.52 percent copper, 2.07 percent lead, 6.31 percent zinc, 71.8 grams of silver per tonne, and 0.637 grams of gold per tonne (Andover Mining Corporation, 2012).
Indication of production None
Reserve estimates None, a 2013 resource estimate was made for nearby Sun (SP039) (Gustin and Ronning, 2013).
Production notes None.



Reporters A. Angel and V.C. Zinno (Alaska Earth Sciences, Inc.)
Last report date 12/4/2014