NOM

Prospect, Active

Alternative names

Golden Range

Commodities and mineralogy

Main commodities Ag; Au; Cu
Other commodities Bi; Te; Sb
Ore minerals arsenopyrite; gold; stibnite
Gangue minerals carbonate minerals; quartz

Geographic location

Quadrangle map, 1:250,000-scale GU
Quadrangle map, 1:63,360-scale D-1
Latitude 62.89
Longitude -144.0392
Nearby scientific data Find additional scientific data near this location
Location and accuracy The NOM target is about 12.7 miles north-northwest of Slana. It is about 3.4 miles northwest of VABM 6677 'Ahtell' and about 0.2 mile southwest of the center of section 23, 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 NOM prospect are diorite and quartz diorite of the Permian to Pennsylvania Ahtell pluton (Richter, 1966; Richter and others, 1975; Wilson and others, 1998; Corvus Gold Inc., 2012). The rocks are cut by extensive dike swarms and faults. The mineralization is on the northeast side of a regional-scale northwest-striking fault.
The NOM prospect may have been sampled in 1980 when WGM Inc. on behalf of the Ahtna Native Corporation searched for the source of geochemical anomalies in gold that outlined a northwest-trending area several miles long that WGM had identified in 1979 (WGM Inc., 1979, 1980). In 1980, they collected several rock samples at scattered locations along the trend that contained up to 3,260 parts per billion (ppb) gold.
In 2010, Corvus Gold Inc. revisited the area, outlined an area of mineralization 2 by 9 kilometers in size, and called it the Golden Range prospect area. They collected more than 300 rock and soil samples in the area. The 151 rock samples averaged 0.6 gram of gold per tonne; 29 of the 151 had more than 0.10 gram of gold per tonne, and the best had 50.4 grams of gold per tonne (Corvus Gold Inc., 2011).
By 2011, Corvus had identified at least 5 specific prospects in the Golden Range target area that they had sampled and drilled (Corvus Gold, Inc., 2012). One is the NOM prospect where they drilled 4 holes and dug 3 trenches. Notable intercepts in the drill holes were: 1) 8.0 meters that averaged 0.48 gram of gold per tonne and 1.57 grams of silver per tonne; 2) 5.1 meters that averaged 0.90 grams of gold per tonne and 0.76 gram of silver per tonne; 3) 6.5 meters that averaged 0.60 gram of gold per tonne and 1.27 grams of silver per tonne, and 4) 3.1 meters that averaged 0.90 gram of gold per tonne and 0.96 gram of silver per tonne. The best sample in a trench was 7.50 meters that averaged 3.26 grams of gold per tonne and 4.74 grams of silver; this included 2.0 meters that averaged 10.40 grams of gold per tonne and 10.91 grams of silver per tonne.
No details on the mineralization are available but it is probably similar to that at the nearby Notch prospect (GU045) arsenopyrite-quartz veins are in a thick mineralized zone marked by sericitic and quartz-carbonate alteration (Myers and others, 2011).
Brown and others (2012) have defined rock geochemical signatures at NOM as follows: 3.1 to 1 ratio of silver to gold, 280 to 1 ratio of arsenic to antimony, 3 to 1 ratio of bismuth to tellurium, and 69 to 1 ratio of arsenic to copper.
Geologic map unit (-144.041307035922, 62.8897129629104)
Mineral deposit model Mineralized zone with arsenopyrite-quartz veins - polymetallic veins? (Cox and Singer, 1986; model 22c)
Mineral deposit model number 22c?
Age of mineralization Younger than the Permian to Pennsylvanian host rocks (Corvus Gold Inc., 2012).
Alteration of deposit Extensive silica-carbonate alteration of diorite and quartz diorite? (Corvus Gold Inc., 2012).

Production and reserves

Workings or exploration The NOM prospect may have been sampled in 1980 when WGM Inc. on behalf of the Ahtna Native Corporation searched for the source of geochemical anomalies in gold that outlined a northwest-trending area several miles long that WGM had identified in 1979 (WGM Inc., 1979, 1980). In 1980, they collected several rock samples at scattered locations along the trend. In 2010, Corvus Gold Inc. revisited the area, outlined an area of mineralization 2 by 9 kilometers in size, and called it the Golden Range prospect area. They collected more than 300 rock and soil samples in the area. By 2011, Corvus had identified at least 5 prospects in the Golden Range prospect area that they had sampled and drilled (Corvus Gold, Inc., 2012). One is the NOM prospect where they drilled 4 holes and dug 3 trenches.
Indication of production None
Reserve estimates None.
Production notes None.

Additional comments

The 2014 version of this record removed the site name 'Corazon' from 2012 version of record since prospects are geologically distinct and results are reported separately for each record (Myers and others, 2011; Brown and others, 2012).

References

References

Corvus Gold Inc., 2012, Chisna: http://www.corvusgold.com/projects/alaska/chisna/ (as of March 1, 2012).
Myers, Russell, Brown, Chris, Taylor Christ, Wilkins, Andres, Burnett, Bill, Stroup, Caleb, Keeley Josh, Benchley, Kristen, Robinson, John, Van Wyck Nick, and Jacobs, Joe, 2011, Golden Range- A new high grade gold discovery in Alaska: Alaska Miners Association, 2011 Annual Convention Abstracts, p. 37.
Richter, D.H., Lanphere, M.A., and Matson, N.A., Jr., 1975, Granite plutonism and metamorphism, eastern Alaska Range, Alaska: Geological Society of American Bulletin, v. 86, p. 819-820.
WGM Inc., 1979, 1978 Annual Progress Report, Uranium Exploration, Ahtell Creek Area, Volume I: WGM Inc., 39 p., appendices, 4 maps. (Report available, Ahtna Mineral Co., Anchorage, Alaska).
WGM Inc., 1980, 1979 Summary report of gold potential, Slana District, Ahtna project: WGM Inc., 10 p., map, scale 1:63,360. (Report held by Ahtna Mineral Co., Anchorage, Alaska).
Reporters D.J. Grybeck (Contractor, USGS); V.C. Zinno (Alaska Earth Sciences, Inc.)
Last report date 12/8/2014