Long

Prospect, Active

Alternative names

Copper King
Hector Group
Long Creek

Commodities and mineralogy

Main commodities Ag; Au; Cu
Other commodities Mo; Zn
Ore minerals chalcopyrite; molybdenite; pyrite; pyrrhotite
Gangue minerals quartz; skarn minerals

Geographic location

Quadrangle map, 1:250,000-scale HE
Quadrangle map, 1:63,360-scale A-6
Latitude 63.1958
Longitude -149.6575
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Copper King prospect is at an elevation of about 3,450 feet near the head of Long Creek. The site is near the center of the east boundary of section 9 , T. 20 S., R. 11 W. The location is accurate to within 0.2 mile.

Geologic setting

Geologic description

Ross (1933) reported the mineralized rock comprises lenses and seams of massive pyrrhotite and chalcopyrite in silicified limestone containing chlorite and probably other silicates. The larger masses parallel the bedding of the cherty rocks. The strike of the beds in this vicinity ranges from N 20 E to N 55 E with the average closer to the latter. The main trench showed mineralization at intervals throughout its length of about 70 feet but exposed massive sulfide only over a width of 2 or 3 feet about 15 feet from its northwest end. A sample of freshly blasted material yielded on assay 0.22 ounce of gold and 4.90 ounces of silver to the ton and 7.34 percent of copper. Trenches about 45 feet to the southwest on the line of strike show little mineralization. The continuation of the same beds in bluffs about 1,000 feet to the northeast contained no visible copper minerals. A very little copper stain and a little pyrite were present in a limestone bed on the approximate line of strike in the gorge of Long Creek about 2,000 feet to the southwest. There are several scattered pits in the vicinity, but copper was not observed in any of them.
The Copper King prospect is primarily a skarn deposit. The country rocks are hornfelsed Permo-Triassic redbeds that consist of calcareous siltstone, and conglomerate; these have been intruded by Upper Cretaceous(?) quartz porphyry dikes. The deposit chiefly consists of massive chalcopyrite, pyrite, and pyrrhotite in a skarn zone 20 to 40 feet thick that is exposed for about 200 feet at the surface. Subsidiary zones of quartz-stockwork veins and disseminated sulfides also occur (unpublished report by Addwest Minerals International Ltd., 1997). The pattern of mineralization suggests a zonal distribution of copper around quartz porphyry intrusions. This is the only prospect in the district explored primarily for copper and is also the only prospect in the area where arsenopyrite has not been found (Hawley and Clark, 1974). In addition, molybdenite is more abundant here than at other nearby prospects; e.g., the Golden Zone Mine (HE043). Ross (1933) reported a sample yielded 7.34 percent copper, 4.9 ounces of silver, and 0.22 ounce of gold per ton.
Through 1999, the exploration included geochemical soil surveys, 1,500 feet of trenching, and 9 drill holes that totaled 1,700 feet. As part of the Golden Zone project, there was some work done at or near this prospect from 2001 to 2005 (Hidefield, 2005 and 2008). The work included some initial ground geophysical surveys. One hole was drilled in 2005. The best interval contained 2.04 grams of gold per tonne across 1.5 meters. In 2011, Alix Resources Corp. drilled 4 holes totaling 434 meters to test the stratigraphy of the redbeds. The results were encouraging with many intercepts up to 9 meters long that contained more than 0.1 gram of gold per ton. But the richest, 1.5 meters long, only contained 0.90 gram of gold per tonne.
Geologic map unit (-149.659790758595, 63.1953253939356)
Mineral deposit model Cu skarn (Cox and Singer, 1986; model 18b).
Mineral deposit model number 18b
Age of mineralization Late Cretaceous?
Alteration of deposit Skarn zones contain diopside, epidote, sericite, and anhydrite.

Production and reserves

Workings or exploration
Ross (1933) reports several trenches were dug in August 1931 for exploration. The main trench showed mineralization at intervals throughout its length of about 70 feet but exposed massive sulfide only over a width of 2 or 3 feet about 15 feet from its northwest end. A sample of freshly blasted material yielded on assay 0.22 ounce of gold and 4.90 ounces of silver to the ton and 7.34 percent of copper. Trenches about 45 feet to the southwest on the line of strike show little mineralization.
Through 1999, the exploration included geochemical soil surveys, 1,500 feet of trenching and 9 drill holes that totaled 1,700 feet. As part of the Golden Zone project, there was some work done at or near this prospect from 2001 to 2005 (Hidefield, 2005 and 2008). The work included some initial ground geophysical surveys; one hole was drilled in 2005. Alix Resources Corp. drilled 4 holes in 2011 (Alix Resources Corp., 2012).
Indication of production None

References

MRDS Number A011305

References

Alix Resources Corp., 2012, Alix announces completion of 2011 program at the Golden Zone property, Alaska: http://www.alixresources.com/index.php?page=news&id=1104 (News release, Jan 5, 2012).
Hidefield Gold Plc., 2005, Final Phase I drill results from Gold Zone project, Alaska: http://www.hidefieldgold.com/s/NewsReleases.asp?ReportID=121135&_Type=News-Releases&_Title=Final-Phase-I-Drill-Results-Received-from-Golden-Zone-Project-Alaska (News Release, Nov 1, 2005).
HIdefield Gold Plc., 2008, Golden Zone: http://www.hidefieldgold.com/s/GoldenZone.asp (as of May 24, 2008).
Reporters N. Van Wyck (Stevens Exploration Management Corporation); D.J. Grybeck (Contractor, USGS); F.H. Wilson (USGS)
Last report date 3/28/2016