Copper North explores Redstone belt

Copper North Mining Corp. July 20 reported that its application for a five-year Type 'A' land use permit, submitted in support of its 2012 exploration program at the Redstone Property in Northwest Territories has been approved by the Mackenzie Valley Land and Water Board.

A LUP has been granted to Redbed Resources Corp., a wholly owned subsidiary of Copper North. The LUP will enable the company to conduct exploration activities on the Redstone property for a period of five years from the date of grant.

The Redstone Property is located in the Nahanni Mining District of Northwest Territories, some 290 kilometers (180 miles) south of Norman Wells, Nwt. and 300 kilometers (186 miles) north of Watson Lake, Yukon Territory. The Redstone property is comprised of a discontinuous series of five mining leases and 13 mineral claims stretching over about 100 kilometers (62 miles) that extend northwest-southeast for about 180 kilometers (112 miles) in the Nahanni Mining District across known sedimentary rock-hosted copper deposits.

The property covers a broad, remote plateau of gentle relief which drops gently to Silverberry River and is accessed by airplane, equipped with floats or skis.

Copper North reported that field crews have been mobilized to a field camp where the focus of 2012 exploration program - comprised of geological mapping, ground geophysics and geochemical sampling - is to test potential deposit extensions at a high-grade, stratiform copper deposit at Coates Lake as well as to increase the company's understanding of the regional prospectivity of the project by further exploring the known copper occurrences in the claims located to the north of Coates Lake.

Strong historical evidence

In May, Copper North reported completion of a review of a historical resource estimate for the Coates Lake deposit at the Redstone property that totals 33.4 million metric tons grading 3.92 percent copper for 2.9 billion pounds contained copper and 11.3 g/t silver (0.33 oz/ton silver) for 12.15 million troy ounces contained silver over a weighted true thickness of 3.27 feet is located on the Coates Lake mining leases.

The Redstone property was extensively drilled between 1960 and 1980 by Redstone Mines Ltd. (geological mapping and 45 diamond drill holes totaling 6,902 meters); Cerro Mining Company of Canada Ltd. (three diamond drill holes totaling 1,375 meters); and Shell Canada Resources Ltd. (eight diamond drill holes for a total of 7,225 meters).

This historical resource estimate was calculated in 1978 by Shell Canada Resources Ltd. and was based upon an unpublished report to Shell entitled "Redstone Project, Progress Report March 1978. Drill Results as of August, 1977 and Recommendations for the 1978 Field Season, Nahanni Mining Division" by A.R., Hildebrand, March 9, 1978. The historical resource estimate prepared by Shell was not created using "Standards of Disclosure for Mineral Projects" as outlined in National Instrument 43-101.

In 2005, however, a technical report by A.W. Gourlay (P.Geol) titled "Technical Report on the Coates Lake Copper Deposit, Nahanni Mining District, Western Northwest Territories for Lumina Resources Corp.," referred to the historical resource estimate from the report for Shell. According to the report, Gourlay considered the calculation of the estimate by Shell to conform with requirements of an inferred resource as defined by NI 43-101.

In 1990 Redstone Mines Limited carried out a complete data review along with confirmation mapping, identification of drill targets and location of potential drill sites.

In 2005 Lumina Resources Corp. completed an exploration program and a regional geological evaluation of the Redstone copper belt.

Need for more drilling

Western Copper Corp. acquired Lumina Resources in November 2006, and spun out the Redstone property into Copper North along with its Carmacks copper project in central Yukon in October. Copper North expects to complete a feasibility study for the Carmacks Project in the third quarter, which will subsequently enable it to complete and submit a revised project proposal to the Yukon Environmental and Socio-economic Assessment Board. An earlier proposal by Western Copper was rejected by the Yukon Water Board in 2010 though it had been approved by YESAB.

At the Redstone property, no exploration drilling has been conducted since the Shell drill program in 1977, which was successful in proving the continuity of the mineralized beds to depth.

Copper North said it does not consider the historical resource estimate as current and further drilling is recommended in order upgrade the historical resource estimate at the Coates Lake deposit. Confirmation drilling is required to verify the historic drill-hole data; once data verification has been achieved, drill-hole lines and spacing would be reduced to about 1,000 meters apart.

Talks with First Nations

Local community engagement in the Northwest Territories was initiated by Copper North in early 2012, in advance of the submission of its application for a land use permit.

In the Sahtu Region, the company has completed a traditional knowledge study, conducted in partnership with the Tulita Renewable Resources Council, the Fort Norman Metis Land Corporation, the Tulita Land and Financial Corporation, and the Tulita District Land Corporation. In the Dehcho Region, the company has met with board representatives of the Pehdzeh Ki First Nation Development Corporation as well as senior representatives of the Liidli Kue First Nation, Fort Simpson (Fort Simpson is the regional centre of the Dehcho).

In a July 20 statement, Copper North President and CEO Sally Eyre, Ph.D., said, "I am very satisfied with our progress as we continue to systematically advance Carmacks and Redstone. Efficient processing of the Redstone LUP application has enabled us to successfully execute our 2012 exploration program, and as a result, we are able to start planning field activities for 2013."

Promising mineral claims

Eyre said the Coates Lake mining leases represent a small proportion of the total area of mineral claims within the Redstone Property.

"Our planned field program this summer will further investigate the potential for extensions to the stratiform mineralized beds within the Transition zone," she explained.

The geophysical work this season will include induced polarization surveys and additional ground-based extremely-low frequency-electromagnetic surveys.

The program is focusing on assessing the lateral and vertical extent of copper mineralization around known mineral occurrences and newly-delineated prospective areas.

The geophysical surveys are being guided by detailed geological mapping of the structures and stratigraphy that control the location of copper mineralization.


Previous field work has been successful in identifying stratiform copper mineralization, structures and stratigraphy using IP surveys at the Coates Lake deposit.

Further exploration is intended to locate potential chargeability and resistivity anomalies associated with copper mineralization, particularly in areas that are covered by overburden.

Copper North said the ground-based ELF-EM system is highly portable, requiring no cut grids or wire loops and is a low-cost means of providing electrical resistivity data to depths of up to one to two kilometers.

The ELF-EM data is relatively rapid to collect and will allow follow-up IP surveys to be more strategically located.
The junior has been working closely with the Mineral Deposit Research Unit of the University of British Columbia to improve regional- and deposit-scale exploration strategies at Redstone.

The collaboration has enabled the company to plan a focused field campaign, which will primarily test potential deposit extensions at the Coates Lake deposit; as well as significantly increase the explorer's understanding of the regional prospectivity of the project.

Seeking drill targets

The 2012 exploration program will focus on the Coates Lake deposit, Johnson Vein, Hayhook Basin and Hidden Valley areas of the property.

The key objectives of the program include testing the potential extensions to the Coates Lake deposit by IP and ELF-EM ground geophysical surveys and geochemical surveys; conducting soil geochemical surveys, biogeochemical surveys, IP surveys and ELF-EM surveys on the Johnson Vein, Hayhook Basin and Hidden Valley claims and leases; and defining new regional exploration targets by prospecting and stream sediment sampling.
The Coates Lake deposit is located within the southeastern portion of the Redstone property, about 116 kilometers (71 miles) northeast of North American Tungsten Corporation Ltd.'s Cantung Mine located near the Yukon border in southwest Northwest Territories.

Copper mineralization at Coates Lake is primarily a high-grade, laterally continuous zone that has a 6,100-meter north-south strike length that extends down-dip to the west for at least 2,400 meters. The deposit is inferred to be open to the north, where the prospective stratigraphy is believed to extend beyond the limit of historic drilling beneath the cover of glacial sediments, and it is inferred to be open at depth to the west and southwest.

Mineralization is disseminated throughout the Coates Lake Group and Rapitan Formation, but the most economically significant mineral occurrences are found in the Transition Zone (a sequence of rocks up to 110 meters thick, containing up to eight copper-bearing beds). At the Coates Lake deposit, the lowermost bed (B1) has the highest grades, although the third bed (B3) has the greatest thickness. Mineralization of the B1 bed at Coates Lake comprises disseminated, inter-grown chalcocite-bornite assemblages with local occurrences of bornite-chalcopyrite in the southeast.

Encouraging samples

The Hayhook Basin located about 80 kilometers (50 miles) north-northwest of Coates Lake has more than 10 known copper occurrences and contains the prospective stratigraphy for laterally-continuous, reduced-facies, stratiform copper-silver deposits.

Much of the prospective stratigraphy in the Hayhook Basin is covered by glacial sediments.

Field work this season is intended to target potential anomalies associated with bedrock mineralization under the overburden.

Grab samples of chalcocite-rich dolostone from the 2010 field season have returned grades of over 13.8 percent copper and 15.6 g/t silver.
The Johnson Vein is a carbonate rock-hosted, fault-related, polymetallic vein copper-silver-zinc-nickel-cobalt occurrence located on a lease about 40 kilometers (25 miles) north-northwest of Coates Lake.

Two grab samples from the 2011 field season taken from historic trenches of massive to semi-massive sulphide rock, returned grades of 16.25 percent copper, 21.1 g/t silver, 0.07 percent zinc, 0.16 percent nickel, 0.026 percent cobalt; and 20.1 percent copper, 123 g/t silver, 0.16 percent zinc, 0.23 percent nickel, 0.041 percent cobalt.

The Johnson Vein has never been drilled and can be traced laterally as talus for at least 450 meters.
The Hidden Valley lease, located about 30 kilometers (19 miles) north-northwest of Coates Lake, covers an area that contains vuggy, hydrothermal dolomite-calcite-quartz-tetrahedrite-chalcopyrite-pyrite breccias that are related to faults within carbonate rocks.

Copper sulphides occur as massive lenses, pods or disseminated tetrahedrite-chalcopyrite.

Although not representative of the breccia rock mass as a whole, samples of massive tetrahedrite lenses from the 2011 field season returned grades as high as 35 percent copper, 1,800 g/t silver, 0.65 percent zinc and 0.45 percent bismuth.
Copper North has said the potential quality and grade of the mineral occurrences at Hayhook Basin, Johnson Vein and Hidden Valley are conceptual in nature because exploration has been insufficient to date to define mineral resources, and it is uncertain whether future exploration will result in the targets being delineated as mineral resources.


Geological similarities

The junior also said the Coates Lake deposit and Hayhook Basin copper occurrences are situated within the 300-kilometer- (186 miles) long and 15-kilometer- (9 miles) wide Redstone Copper Belt which is geologically similar to the large, well-known copper deposits of the Kupferschiefer in north-central Europe and the copper deposits of the Central African Copper Belt in the Republic of Zambia and Democratic Republic of Congo.

Copper occurrences at the Johnson Vein and Hidden Valley properties, also within the Redstone Copper Belt, exhibit different characteristics and can be classified as carbonate-hosted, polymetallic copper-silver-zinc-bismuth-cobalt deposits, according to Copper North.

The junior's exploration program is being supervised by Jack Milton, M.Sc, a University of British Columbia Ph.D. candidate currently working on the Redstone Copperbelt project. 
The 2012 exploration program is expected to cost about C$800,000. Copper North had a cash balance of C$1.88 million as at Dec. 31, and June 1 reported that it raised about C$1 million in a private placement.