Canwell Ridge

Prospect, Active?

Alternative names

Canwell Glacier
Upper Canwell
Lower Canwell

Commodities and mineralogy

Main commodities Au; Co; Cu; Ni; Pd; Pt
Other commodities Ir; Rh; Ru
Ore minerals chalcopyrite; garnierite; malachite; pentlandite; pyrrhotite

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale B-4
Latitude 63.3291
Longitude -145.5919
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Canwell Ridge prospect includes several exploration sites strung out for about 1,100 feet in an ultramafic-mafic complex. The center of the sites is about 2.8 miles east of VABM 5422 'Canwell' at the north end of Rainbow Ridge. It is about 0.3 mile north-northwest of the center of section 26, T. 18 S., R. 11 E., of the Fairbanks Meridian. This location is accurate to within 1/4 mile.

Geologic setting

Geologic description

The Canwell Ridge prospect is in the Triassic, Canwell mafic-ultramafic complex (Nokleberg and others, 1992 [MF]; 1992 [Open-File]; Bittenbender and others, 2007). The complex is a sill-like body that trends west-northwest for about 3.5 miles, dips to the south at about 40 degrees, and is about 1,000 feet thick at this prospect. It has a dunite core that grades outward to wherlite, peridotite, and gabbro. The complex is intruded by Cretaceous quartz-diorite to granodiorite.
Although mineralization at the the Canwell Ridge prospect was recognized earlier (Hanson, 1963, Barker, 1988), serious exploration began in 1994 when American Copper and Nickel Co. (ACNC) working with Fort Knox Gold Resources staked claims over the prospect and flew an airborne geophysical survey that collected magnetic and resistivity data.
Nevada Star Resources Corp. optioned the property in 2001. They drilled 5 holes in 2002. In 2003, Nevada Star built a road to the prospect, brought in a backhoe, dug six trenches across the mineralization, did additional ground geophysical surveys and collected geochemical samples to define drill targets. They drilled 6 holes in 2004 that totaled 2,275 feet. The Bureau of Land Management examined the prospect in the early 2000s and collected a few samples (Bittenbender and others, 2007).
The mineralization at the Canwell Ridge prospect consists of disseminated to massive pyrrhotite with chalcopyrite and pentlandite that is mainly in gabbro near the base of the Canwell complex. Additional sulfide mineralization was introduced in gabbro dikes. The 2003 trenching by Nevada Star indicated that the mineralization extends for 1,100 feet and is up to 25 feet wide. The most impressive mineralization is a layer of massive sulfides about a foot thick that parallels the trend of the Canwell complex and can be traced for about 300 feet.
There is abundant assay data from the many episodes of sampling and drilling by several companies and organizations (Ellis, 2002 [Delta River]; Ellis, 2002 [Eureka Creek}; Freeman, 2004; Bittenbender and others, 2007).
Geologic map unit (-145.594149743084, 63.3286896277257)
Mineral deposit model Synorogenic-synvolcanic Ni-Cu (Cox and Singer, 1986; model 7a)
Mineral deposit model number 7a
Age of mineralization Magmatic sulfides are related to the emplacement of a Triassic mafic-ultramafic complex (Bittenbender and others, 2007).
Alteration of deposit The gabbro is moderately silicified and serpentinized (Bittenbender and others, 2007).

Production and reserves

Workings or exploration
Although mineralization at the the Canwell Ridge prospect was recognized earlier (Hanson, 1963, Barker, 1988), serious exploration began in about 1995 when American Copper and Nickel Co. (ACNC) working with Fort Knox Gold Resources staked claims over the prospect and flew an airborne geophysical survey that collected magnetic and resistivity data. In 1997, a UTEM Ground geophysical survey identified several targets and they drilled two holes. They did additional ground geophysical surveys in 1998 and drilled five holes. Nevada Star Resources Corp. optioned the property in 2001 and after Fort Knox abandoned their claims, Nevada Star re-staked the property. They drilled 5 holes in 2002. In 2003, Nevada Star built a road to the prospect, brought in a backhoe, dug six trenches across the mineralization, did additional ground geophysical surveys and collected geochemical samples to define drill targets. They drilled 6 holes in 2004 that totaled 2,275 feet. The Bureau of Land Management examined the prospect in the early 2000s and collected a few samples (Bittenbender and others, 2007).
In 2009, Pure Nickel Inc. reported grab sample assay result highlights of up to 13.7 percent nickel, 2.9 percent copper, 0.2 percent cobalt, 19.9 grams per tonne of platinum, 5.13 grams per tonne of palladium, 0.19 grams per tonne of rhodium, 0.26 grams per tonne of iridium, and 0.36 grams per tonne of ruthenium (Pure Nickel Inc., 2009).
Indication of production None
Reserve estimates None.
Production notes None.

References

References

Barker, J.C., 1988, Distribution of platinum-group elements in an ultramafic complex near Rainbow Mountain, east-central Alaska Range, IN Vassilou, A.H., Hausen, D.M., and Carson, D.J.T, eds, Process Mineralogy VII, Applications to mineral beneficiation: Proceedings of the Metal Society SME/AIME Joint [Annual] Meeting, Denver, Colo., p. 197-220.
Bittenbender, P.E., Bean, K.W., Kurtak, J.M., and Deininger, James Jr., 2007, Mineral assessment of the Delta River Mining District area, east-central, Alaska: U.S. Bureau of Land Management, Alaska Technical Report 57, 675 p.
Ellis, W.T., 2002, MAN Ni-Cu-PGE project - Delta River Mining District, Central Alaska Range: Report on 2002 exploration activities: Unpublished report prepared for the Nevada Star Resource Corp. by Alaska Earth Science Inc., 74 p.
Ellis, W.T., 2002, Summary report for the Eureka Creek, Tangle Lakes Ni-Cu-PGE project - Delta River Mining District, Central Alaska Range: Unpublished report prepared for the Nevada Star Resources Corp. by Alaska Earth Sciences Inc., 51 p.
Freeman, C.J., 2004, Executive summary report for the MAN project, Delta River Mining District, Alaska: Unpublished report, prepared by Avalon Development Corp., Geologic Report MN04EXE1, 40 p.
Pure Nickel Inc., 2009, Pure Nickel Update: http://www.purenickel.com/ppt/PNI_Investor_Presentation%20_May09.pdf (as of July 9, 2014).
Reporters W.T. Ellis (Alaska Earth Sciences), C.C. Hawley (Hawley Resource Group), and W.J. Nokleberg (USGS); D.J. Grybeck (Contractor, USGS); V.C. Zinno (Alaska Earth Sciences, Inc.)
Last report date 12/8/2014