North Fox

Prospect, Active

Commodities and mineralogy

Main commodities Au
Other commodities Ag; As; Hg; Sb
Ore minerals arsenopyrite; gold; pyrite
Gangue minerals calcite; quartz

Geographic location

Quadrangle map, 1:250,000-scale TE
Quadrangle map, 1:63,360-scale D-2
Latitude 65.7957
Longitude -165.9691
Nearby scientific data Find additional scientific data near this location
Location and accuracy The North Fox prospect is about 12.1 miles southeast of Ear Mountain. It is about 0.7 mile north-northeast of hill 1180 and about 0.6 mile northeast of the center of section 35, T 5. N., R. 35 W. The location is accurate.

Geologic setting

Geologic description

The North Fox prospect is in mica-quartz schist and graphitic quartz schist intercalated in a metasedimentary sequence that includes schistose, micaceous, dolomitic marble; mica-calcite schist; and minor micaceous quartzite (Cedar Mountain, 2011 [project]). The sequence is interpreted as a limestone-shale assemblage with facies variations. It is highly deformed and perhaps isoclinally folded. Schistosity dips moderately in various directions. Steeply-dipping marble-schist contacts and other strong linear features may indicate normal faults. The North Fox prospect is along a northwest-trending, regional fault that marks the contact between schist to the southwest and marble to the northeast. All of the metavolcanic and metasedimentary rocks in area were probably Paleozoic originally and have been metamorphosed in the Cretaceous; Sainsbury (1972) however mapped them as Precambrian.
The North Fox prospect is one of several similar deposits that define a district-level, west-northwest trending belt of gold mineralization about 11 miles long and 2 miles wide. The best known and most extensively explored of these is the Kelly Creek prospect (TE069) about 2.6 miles to the southeast; other are the South Fox (TE108), Wolf (TE107), Wolverine (TE110), Moose (TE111), and Jaeger (TE112) prospects.
The prospect was discovered by following up gold and arsenic anomalies in soils and stream sediments from the west headwaters of Kelly Creek (Hudson and Wyman, 1983; Hudson, 1984; Cedar Mountain, 2011 [assay]; Cedar Mountain, 2011 [November 2, news release], Cedar Mountain, 2011 [November 2 map]) The gold, arsenic, and antimony values define strong, coherent, multi-element anomalies. Mercury is commonly elevated in the soils, but its distribution and concentration are more erratic and it is more widely dispersed at anomalous levels than the other three elements. Rock samples from frost boils show that the stronger anomalies are associated with silicified breccia and quartz-stocks in sooty, black carbonaceous quartz schist.
Clay is locally present in fractures and as part of the matrix in breccia. Dolomite and calcite reportedly accompany quartz in the veins in some drill core (Marrs and Ivey, 1984). Pyrite is disseminated in pelitic schist and is present in all mineralized rocks; in part, it is probably of sedimentary origin. Quartz segregations along the foliation in pelitic schist are recrystallized, sugary textured, and vuggy in the mineralized rocks.
Cedar Mountain Exploration Inc. acquired the property in March 2010 and began aggressive exploration (Cedar Mountain Exploration Inc., 2011 [Kelly Creek]). In 2011, they drilled six holes at North Fox that totaled 668.5 meters on a geochemical anomaly in carbonaceous schist (Cedar Mountain, 2011 [November 2, news release], Cedar Mountain, 2011 [November 2 map]). All the holes cut intervals with more than 0.1 gram of gold per tonne. The gold intersects are relatively narrow and low grade. Some notable intercepts are 4.5 meters with 0.32 gram of gold per tonne, 4.5 meters with 0.42 gram of gold per tonne, 4.5 meters with 0.50 gram of gold per tonne, and 4.5 meters with 0.70 gram of gold per tonne. However the grade increase systematically toward the eastern end of the gold-in-soil geochemical anomaly that extends beyond the drilling. The gold-bearing zones are in sheared and quartz-veined, partly calcareous, mica-graphite-quartz schist.
Geologic map unit (-165.971831586773, 65.794961160921)
Mineral deposit model Disseminated and stockwork quartz and gold mineralization in metapelitic rocks. Possibly carbonate-hosted Au-Ag and/or low sulfide Au-quartz vein (Cox and Singer, 1986; models 26a or 36a).
Mineral deposit model number 26a or 36a?
Age of mineralization Unknown but probably mid-to Late Cretaceous as the mineralization postdates regional metamorphism.
Alteration of deposit Brecciation, silicification, and quartz stockwork veining is common in pelitic schist. Some quartz veins contain carbonate minerals. Clay and limonite are present in some mineralized rocks.

Production and reserves

Workings or exploration The North Fox prospect was discovered by following up gold and arsenic anomalies in soils and stream sediments from the west headwaters of Kelly Creek (Hudson and Wyman, 1983; Hudson, 1984; Cedar Mountain, 2011 [assay]; Cedar Mountain, 2011 [November 2, news release], Cedar Mountain, 2011 [November 2 map]) Cedar Mountain Exploration Inc. acquired the property in March 2010 and began aggressive exploration (Cedar Mountain Exploration Inc., 2011 [Kelly Creek]). In 2011, they drilled six holes at North Fox that totaled 668.5 meters on a geochemical anomaly in carbonaceous schist (Cedar Mountain, 2011 [November 2, news release], Cedar Mountain, 2011 [November 2 map]). All the holes cut intervals with more than 0.1 grams of gold per tonne. The gold intersects are relatively narrow and low grade. Some notable intercepts are 4.5 meters with 0.32 gram of gold per tonne, 4.5 meters with 0.42 gram of gold per tonne, 4.5 meters with 0.50 gram of gold per tonne, and 4.5 meters with 0.70 gram of gold per tonne. However the grade increases systematically toward the eastern end of the gold-in-soil geochemical anomaly that extends beyond the drilling. The gold-bearing zones are in sheared and quartz-veined, partly calcareous, mica-graphite-quartz schist.
Indication of production None
Reserve estimates None.
Production notes None.

References

References

Cedar Mountain Exploration, 2011, Cedar identified new gold targets at Kelly Creek project: http://www.cedarmountainexp.com/news/index.php?&content_id=86 (News Release, November 18, 2011).
Cedar Mountain Exploration, 2011, Drilling confirms bedrock gold source at Kelly Creek project: http://www.cedarmountainexp.com/news/index.php?&content_id=85 (News release, November 2, 2011).
Cedar Mountain Exploration Inc., 2011, Kelly Creek project: http://www.cedarmountainexp.com/projects/alaska/kelly_creek_project/ (as of Feb. 10, 2011).
Cedar Mountain Exploration Inc., 2011, New assay date upgrades Cedar Mountain's Kelly Creek Project: http://www.cedarmountainexp.com/_resources/CED_2011_01_25.pdf (News release, January 25, 2011).
Hudson, T.L., 1984, 1983 Seward Peninsula reconnaissance project: Anchorage, Alaska, Anaconda Minerals Company internal report (Report held by Cook Inlet Region, Inc., Anchorage, Alaska).
Hudson, T.L., and Wyman, W. F., 1983, Interim report on areas of Seward Peninsula warranting further prospecting and evaluation: Anchorage, Anaconda Minerals Company internal report, 84 p., 7 plates. (Report held by Cook Inlet Region Inc., Anchorage, Alaska.)
Marrs, C.D., and Ivey, J.A., 1984, 1984 Prospect evaluation project; Kelly Creek (Fox claims): Anchorage, Alaska, Anaconda Minerals Company internal report. (Report held by Cook Inlet Region, Inc., Anchorage, Alaska).
Reporters D.J. Grybeck (Contractor, USGS)
Last report date 4/1/2012