Frozen Creek

Prospect, Active?

Commodities and mineralogy

Main commodities Au; Cu
Other commodities Ag
Ore minerals chalcopyrite; magnetite; pyrite; pyrrhotite
Gangue minerals tourmaline

Geographic location

Quadrangle map, 1:250,000-scale MD
Quadrangle map, 1:63,360-scale C-4
Latitude 63.532
Longitude -154.513
Nearby scientific data Find additional scientific data near this location
Location and accuracy
The Frozen Creek prospect is situated on a south rim of an east-facing cirque valley on the east side of the Mystery Mountains at an elevation of 2,500 feet (762 m) in Section 6, T. 23 S., R. 22 E., of the Kateel River
Meridian. Prospect is known to within 250 feet (76 m).

Geologic setting

Geologic description

The Frozen Creek prospect consists of a large zone of boron metasomatism in the eastern edge of the Mystery Mountains Pluton. It is the eastern-most porphyry-like prospect in a seven mile (11 km) long northeast-trending zone of similar prospects that cut across the central Mystery Mountains. The Frozen Creek prospect is inferred to be Late Cretaceous based on isotopic age of Mystery Mountains intrusive complex (Moll and others, 1981).
A strong copper-gold soil anomaly was detected at Frozen Creek (DiMarchi and others, 1997), which is part of the core of Cu-Au anomalies that are surrounded by a lead-zinc mineral zonation. Disseminated chalcopyrite and pyrrhotite are found throughout a tourmaline-enriched monzonitic plutonic rocks; little mineralization is noted in host biotite hornfels. Malachite is locally abundant in hairline fractures in small intrusive bodies. The mineralized zone at Frozen Creek is at least 1,500 feet (457 m) in diameter. Two grab samples of mineralization collected by Clautice and others (1993) averaged 585 ppm copper and 2.1 ppm silver.
Geologic map unit (-154.51534334278, 63.5314039355488)
Mineral deposit model Porphyry Cu-Au (Cox and Singer, 1986; model 20c).
Mineral deposit model number 20c
Age of mineralization The Frozen Creek prospect is inferred to be Late Cretaceous based on isotopic age of Mystery Mountains intrusive complex (Moll and others, 1981).
Alteration of deposit Sericite and secondary biotite in pluton.

Production and reserves

Workings or exploration
The Frozen Creek prospect was found during regional exploration conducted by WGM Inc. in 1977 (Andrews, 1978). American Copper and Nickel Inc. (ACNC) worked on the prospect from 1988 to 1990, and ASA Inc. continued work through 1997 (DiMarchi and others, 1997). During 1989-1991, ACNC explored the area as a porphyry copper-gold target. ASA Inc. continued exploration work with the same target in mind during 1995 and 1996. Two grab samples reported by Clautice and others (1993) averaged 585 ppm copper and 2.1 ppm silver.
Newmont Mining Corporation (2012) collected soil samples on ridges and spurs with a nominal spacing of 100 meters and followed up with grid soil samples in 2010 and 2011. Soil samples having assays of greater than 100 ppb gold and 1,000 ppm copper form an elongate anomalous zone of approximately 1,100 meters long. High-grade gold and copper assays in soil samples are centered on a zone of 3 to 5 granite porphyry dikes that exhibit potassic alteration (Newmont Mining Corp, 2012).
In 2012, drilling by Newmont identified long intercepts of low grade copper and gold (164.5 meters of 0.17 ppm gold and 0.09 percent copper in hole COTT-0004 and 134.1 meters of 0.37 ppm gold and 0.1 percent copper in hole COTT-0005b), hosted in a fine grained to aphanitic andesite (Newmont Mining Corp., 2013).
Indication of production None

Additional comments

See Tarn (MD027), Pork Chop (MD031), Mystery Mt. East (MD028), and Copenhagen Hill (MD030) prospects. The Frozen Creek Prospect is on land selected or owned by Doyon Ltd. For additional information contact Doyon Ltd. at 210 1st Ave., Fairbanks, Alaska, 99701.

References

MRDS Number 10307782

References

Andrews, Tom, 1978, Summary of Progress, Doyon Project, Mystery Mountains (Block 10): Anchorage, Alaska, WGM Inc., 24 p. (Held by Doyon, Limited, Fairbanks, Alaska, as proprietary report 78-42).
Reporters Bundtzen, T.K. (Pacific Rim Geological Consulting); V.C. Zinno (Alaska Earth Sciences, Inc.)
Last report date 3/15/2016