Back to basics: Restarting a high-grade gold producer in Yellowknife

Brian Malahoff, the director of Sixty North Gold Mines Ltd., on a tour of the Mon Property in August 2017.

During the initial staking rush in Yellowknife in the 1930s, a high-grade quartz vein was discovered outcropping along the side of a hill 45-kilometres north of Yellowknife, NWT. Subsequent exploration attempted to trace a planar vein model dipping to the west with limited success. In 1988, the property was optioned from Cominco and the folded nature of the vein was first defined. Drilling to intersect the eastdipping east limb to the south of the surface showing and mining in 1989 extracted 2,300 tonnes grading 18.3 gpt gold (diluted) from 15 metres of elevation in the east stope. In 1991, the central adit was excavated, and the well-exposed western limb was undercut. Over the next six years, 12,500 tonnes grading >27 gpt gold was mined, also from 15 metres of elevation and milled on site.

In 2012, a three-dimensional model was constructed and the multi-ounce grades at the fold nose were shown to be consistent over the mined length of 75 metres, open to south, with lower grade gold values being found as one moves away from the hinge zone.

Sixty North Gold Mining is earning a 100 per cent interest in the property from New Discovery Mines Ltd. by making $6 million in expenditures developing the property. The overall size, grade and form of the mineralization, as well as its host rock assemblage is similar to the Discovery Mine (located 50 kilometres to the north) where onemillion tons of ore were mined and onemillion ounces of gold were recovered between 1949 and 1969.

The project is permitted to operate at 100 tpd similar to what the Discovery Mine and Con Mine started at.

At surface, Sixty North has sampled the crown pillar of the hinge zone over 45 metres with results shown in Figure 1. fiGure 1: trench intersection au Grade (metres) (gpt) 17-1 0.28 20.3 0.50 3.4 17-2 0.50 688.8 0.80 273.1 0.50 2.6 17-3 0.40 5.6 0.60 15.9 17-4 0.40 1.8 17-5 0.50 8.4 17-6 0.50 4.9 0.50 390.0 0.60 3.0 17-7 0.50 16.3 0.90 1.2 17-8 0.90 143.9 17-9 0.50 65.0 0.50 311.6 0.70 198.8 17-10 1.00 60.2 0.90 27.7

New Discovery Mines Ltd., currently holds renewable permits to mine, process, and dispose of tailings for the Mon Property.

It is planned to acquire additional equipment and supplies, and to construct a winter road to site in early 2021 to mobilize a camp and equipment to site. The north portal will be re-opened and extension of the main ramp will be driven 200-metres down to the south to allow for cross-cuts to be driven into the A-Zone vein 20-metres below the historic stopes that had produced at around one ounce per tonne. Several thousand tonnes of vein material are planned to be collected during this phase for sampling, testing, and ultimately processing in early 2022.

A total of eight personnel would be on the property in 2021 until milling starts in 2022 when an additional four personnel would be needed with a similar number off property on rotation.

Exploration on the property has traced the A-Zone to the south for an additional 1.5 kilometres to the south, and additional zones have been identified, including shear zone hosted gold mineralization that has returned up to 7.22 gpt gold over a true width of 6.0 metres. No shear zone targets have been drilled on the property. In 2019, a precious metals-rich volcanogenic massive sulphide deposit was discovered, grading 203 gpt silver, 1.0 gpt gold, 0.6 per cent lead and 1.0 per cent zinc over 0.45 metres. Geophysics has traced this zone to where larger and stronger anomalies lay under cover of overburden and lakes. Drilling is planned in the future. 8

Dave Webb and Peter VanAdrichem examining the crown pillar of the East Stope (filled raise) of the A-Zone, Mon Property. Ladder is at the hinge zone of the folded quartz vein which is marked with red paint. Photo taken in summer 2012.

yellowknife employee uses a percussion hammer to collect material for metallurgical testing from the crown pillar of the A-Zone, Mon Property in spring 2018.

Google Earth image of the western Slave Province showing the location of some current gold projects.