Carmacks Project, Yukon Territory, Canada

In January 2024, Granite Creek announced metallurgical testing results with further exploration plans planned in the year.

Carmacks Project Location and Site Details

The Carmacks Property, including Carmacks and Carmacks North properties, is located approximately 210km northwest of Whitehorse and approximately 47km northeast of the Carmacks Village in the Yukon Territory.

The project is situated within 20km of paved highway and grid power. The Minto Mine is situated 42km northwest of the project’s camp.

The project can be accessed by taking Freegold Road (maintained by the Yukon Government) for 34km to the northwest of Carmacks followed by travelling 13km on the Carmacks Project access trail. The Carmacks Village can be reached by travelling 175km on a paved road north of Whitehorse.

As a part of development, a new 13km access road is proposed to be built to access the project site.

A 10km user-maintained gravel road with four creek crossings connects Hoocheekoo Creek located in the middle of the Carmacks North Property region. The road lies beyond the Carmacks Project camp.

The Carmacks North Property is accessible by a helicopter flight of 15-20 minutes from the Carmacks Property.

The port of Anchorage is 1,133km west and Skagway is 180km south of the Whitehorse. The port of Stewart lies 1,043km south and Prince Rupert is 1,373km south of the Whitehorse.

Carmacks Project Ownership History

Dr. G.M. Dawson reported the first copper discovery in the region in 1887 at Hoocheekoo Bluff on the Yukon River.

In the late 1960s, the Casino porphyry copper deposit was discovered by exploration in the porphyry copper deposits in the Dawson Range.

The discovery led to the staking of the Williams Creek Property in 1970 by G. Wing and A. Arsenault of Whitehorse.

The Dawson Range Joint Venture of Straus Exploration, Great Plains Development of Canada, Trojan Consolidated Minerals, and Molybdenum Corporation of America optioned the property and conducted geochemical sampling and reconnaissance prospecting via Archer, Cathro and Associates. This led to the discovery of zones 1 and 2.

In 1971 and 1972, extensive drilling and exploration campaigns were conducted on the property. Western Copper Holdings and Thermal Exploration purchased the property in 1991 and conducted diamond drilling in 36 holes followed by a baseline environmental survey.

In 1992, Western Copper and Thermal Exploration drilled 1,164m in eight diamond drill holes, and 11 reverse circulation holes, and conducted metallurgical test work with a baseline environmental testing and a biophysical assessment of the area.

Western Copper and Thermal Exploration merged to become Western Copper Holdings in 1995. In February 2003, Western Copper Holdings changed its name to Western Silver Corporation due to a corporate redirection towards silver mining.

In late 2004, Western Silver agreed to re-enter the permitting process and re-engaged in the environmental review process with the Yukon Territorial Government.

Glamis Gold purchased Western Silver in early 2006 resulting in the formation of a separate company, Western Copper Corporation.

Western Copper split into three companies: Copper North Mining Corp., NorthIsle Copper & Gold Inc., and Western Copper and Gold Corporation in October 2011. Copper North retained the Carmacks Project.

In 2016, a PEA was completed for Copper North’s Carmacks Project. In October 2018, Granite Creek Gold changed its name to Granite Creek Copper.

Copper North signed a comprehensive data-sharing agreement with Granite Creek Gold in April 2019 about the existing mineral exploration data on Copper North’s adjoining mineral claims in the Carmacks Copper District.

In November 2020, Granite Creek Copper completed the acquisition of Copper North.

Geology and Mineralisation

Carmacks Copper deposit lies in the Early Jurassic Granite Mountain batholith composite in structure.

The copper deposit area is situated near the northwestern limit of Pleistocene glaciation and hosted within a series of elongated north-to-northwest trending inliers of amphibolite facies mafic to intermediate meta-igneous rocks.

The inliers also contain migmatitic derivatives in massive granitoids of the Granite Mountain batholith. The mafic rocks include foliated and equigranular amphibolite textured with less foliated hornblende-porphyryoblastic amphibolite with rare augite gabbro.

The mineralisation of the Carmacks deposit occurs within a 3km north-northwest trending belt. The belt includes the main zone (zones 1,4,7, and 7A) in the north and zones 2000S, 12, and 13 in the south.

The bulk of hypogene copper mineralisation is hosted within the migmatitic rocks.

Silver is present in bornite as hessite inclusions and since gold and silver are associated with bornite hence, the bornite-chalcopyrite ± digenite zone is enriched with precious metals. The migmatite hosts higher grades of copper, silver, and gold than the quartz-plagioclase-biotite schist sequence and amphibolite.

Mineral Resource Estimate

According to the updated mineral resource estimate, announced in March 2022, Carmacks deposit contains 36.2 million tonnes (Mt) in Measured and Indicated categories (M&I), grading 1.07% CuEq (0.81% Cu, 0.26g/t Au, 3.23g/t Ag and 0.011% Mo) for a total of 651 million pounds (Mlbs) of contained M&I copper.

It hosts an additional 38Mlbs Cu in Inferred category.

Mining Methods and Processing of Ore

The method proposed for mining ore from the project is conventional open-pit mining.

In this method, a slot will be developed in front of the mineralised zone at each level. The central slot will allow waste mining and mineralised material mining and the separation of the mineralised material from the waste material.

The mineralised material will be drilled, blasted, and loaded into off-highway dump trucks using hydraulic shovels and hydraulic excavators and hauled to the processing plant for processing.

The run-of-mine feed consisting of mineralised oxide and sulphide of copper, gold, and silver will be processed in a processing plant capable of processing 7,000 tonnes per day.

The mill feed will be crushed in a primary crushing circuit reducing the feed to a P₈₀ of 150mm or less in size.

The reduced material will be grinded in a grinding circuit consisting of one SAG mill and one ball mill. The mills will operate in a closed circuit using hydrocyclones producing a final product of 150um.

The final product of 150um will enter a rougher flotation circuit consisting of a rougher concentrate regrind circuit. The circuit will produce a rougher concentrate which will undergo two stages of cleaning in a cleaner flotation circuit producing the final concentrate.

The final concentrate will undergo thickening and filtration and will become ready for export. The tailings will be handled by a tailing handling facility.

Infrastructure

The Carmacks Project will require access roads, a mill complex, a site development and access, a water management plan, a tailing storage facility and associated water management structures.

The other facilities will include a 100-person camp, warehouses, offices, and electrical site reticulation and generated power infrastructure.

Power Supply and Transmission

The expected electrical demand load for open-pit mining operations is approximately 10MW.

The mine will have diesel power generators as the primary power source during construction and pre-production.

Grid power will be supplied after the second production year of the mine. For the first four years, power will be supplied by generators starting at 1.8MW and increasing up to 9.6MW during the first and second production years.

The main substation of the project will house a transformer skid of 10MVA and 115kV/5kV and accessories, an e-house with 2000 ampere (A) power distribution centre, a protective relaying, generator synchronisation, and load shedding equipment, a 4,160v switchgear, and a substation P&C, synchronisation and network cabinets.

The mill substation will consist of two 4,160/600V 1.5MVA transformers (oil-filled step-down) with secondary 600V and 2000A power distribution centres. These will supply power motor control centres for mill processing and utility equipment.

The power will be supplied to the site by the power distribution centre. The power to the mill substation will be supplied underground and to the remote gatehouse, buildings, and open pit mine via the kV O/H line.

The pole-mounted transformers will step down power supply to remote areas and pad-mounted transformers will step-down power.

The project is to be powered by the Yukon’s electrical grid which uses primarily renewable electricity.

Contractors Involved

In January 2024, the metallurgical studies were conducted successfully by Kemetco Research. The preliminary scoping tests were conducted by Kemetco in August 2023.

SGS Canada prepared the 2023 PEA of the Carmacks Project.

SGS Vancouver Metallurgy completed a metallurgical testing program in January 2023.

In June 2022, a high-resolution and deep-penetrating Induced Polarisation survey was initiated by Simcoe Geophysics on the project.

Goldspot Discoveries was engaged to apply their machine learning technology and geoscience expertise on the Carmacks deposit and Carmacks North area in March 2021.

The mine planning and mineral processing work on the project was conducted by Sedgman Canada and Mining Plus in December 2021. Sedgman Canada and Mining Plus conducted metallurgical testing on the project in October 2021.

Archer, Cathro and Associated conducted reconnaissance prospecting and geochemical sampling of the property.

In 1991, the ground geophysical studies were conducted by Interpretex.

Knight Piésold was contracted by Western Copper and Thermal Exploration in 1991 to conduct geotechnical studies on the deposit. Knight Piésold also initiated a preliminary mine design and clearing and grubbing of a site access road and leach pad area in 1995.

An Airborne, radiometric, and VLF-EM survey in 1993 was conducted by Sander Geophysics.

In 1994, a Feasibility Study of the project was prepared by Kilborn Engineering Pacific. Kilborn produced a basic engineering report of the mine in 1997.

In 2001, Fugro Airborne Surveys conducted a regional fixed wing airborne geophysical survey of the Carmacks area.

In September 2006, Western Copper retained M3 Engineering & Technology Corporation to revise the earlier studies and prepare a bankable level Feasibility Study for the project. M3 updated the Feasibility Study in 2012 for the heap leaching copper recovery from the project.

Copper North selected Merit Consultant International to prepare a PEA of the project in 2014 and commissioned JDS Energy & Mining to complete a PEA for the project in 2016.