North of 60 Mining News - The mining newspaper for Alaska and Canada's North

PolarX Ltd. July 10 said a roughly 5,000-meter drill program is slated to begin this month at the Saturn copper‐gold porphyry target within its Alaska Range project.

Funded with the recent AU$4.3 million investment by Lundin Mining Corp., this program is expected to include eight to 10 deep holes targeting a porphyry copper‐gold target identified in early 2018 through evaluation of regional aeromagnetic geophysical data and confirmed through a higher‐resolution survey carried out late last year.

This magnetic anomaly is about 3,000 meters east of the high‐grade Zackly skarn deposit, a style of mineralization often associated with large mineralized porphyry systems.

Skarn deposits are formed when mineralized fluids come in contact with rock packages, usually containing carbonate-rich rocks, causing the metals to precipitate out, creating a particularly high-grade mineralized body. Porphyries, on the other hand, are formed at the center of the mineralizing event that created the skarn. Because there is not a catalyst that concentrates the minerals, porphyries tend to be lower grade but much larger.

Porphyry deposits currently account for more than half of global copper production and are an increasingly important source of this useful metal. In addition to copper, porphyries tend to carry gold, molybdenum, rhenium and other metals.

The Saturn anomaly is interpreted to be the potential porphyry fluid source for the east‐west trend of skarn mineralization and alteration discovered at Zackly.

This magnetic body lies under 10 to 15 meters of glacial sediments deposited on top, which covers any visual or geochemical evidence at surface.

The geological and geophysical evidence, however, is very compelling.

"The combination of the modelling results, the magnetic responses from the surrounding zone and the close proximity to the high‐grade Zackly skarn copper‐gold deposit means Saturn is shaping up as a text‐book example of a porphyry prospect," PolarX Managing Director Frazer Tabeart said earlier this year.

This magnetic body is the target of the drill program about to get underway.

To target this drilling, the Aussie explorer is carrying out an IP survey this week to locate the presence of disseminated sulfides associated with the intrusive core and in the surrounding alteration halo at Saturn.

Three Alaska Range projects

To accommodate a deal with Lundin Mining, PolarX has subdivided its Alaska Range property into three projects – Stellar, Zackly Skarn and Caribou Dome.

The money Lundin invested to acquire 53.44 million PolarX shares is earmarked for Stellar, which encompasses Saturn and other targets on the large Stellar property that PolarX acquired from Millrock Resources Inc.

Mars, a second copper‐gold porphyry target located at the west end of a 7.5-mile (12 kilometers) structural corridor that runs through the Zackly and to Saturn at the east end, is another compelling porphyry target on the Stellar project.

Zackly hosts 3.4 million metric tons of inferred resource averaging 1.2 percent (90.4 million pounds) copper, 2 grams per metric ton (213,000 oz) gold and 14 g/t (1.5 million oz) silver, according to an Australian Joint Ore Reserves Committee- (JORC) resource calculated in 2017.

While Zackly lies in the middle of the Stellar project, a block of claims covering this skarn deposit and its potential extensions has been excluded from the agreement with Lundin so that PolarX can continue to expand the high-grade resource there.

PolarX also retains ownership of Caribou Dome, a roughly 14-mile-long property immediately southwest of Stellar that hosts 1.6 million metric tons of near-surface JORC-compliant resource (measured, indicated and inferred) averaging 3 percent (107.8 million lb) copper; and 1.2 million metric tons of underground mineable resource averaging 3.2 percent (82.3 million lb) copper.

In addition to making Lundin PolarX' largest shareholder, with a 12.85 percent stake, its investment earns the Toronto-based miner an exclusive option to earn a 51 percent interest in Stellar by investing US$24 million in exploration at the project and making US$20 million in payments to PolarX over the following three years.

Expanding Zackly skarn

PolarX, which continues to hold full ownership of Zackly and all its interest in Caribou Dome copper property southwest of Stellar, is carrying out further drilling this year to define additional near‐surface, high‐grade copper‐gold mineralization at the Zackly skarn.

This drilling, which will run in parallel with the Saturn program, is being funded by an AU$3.5 million financing that was separate from the deal with Lundin.

While the main skarn body that hosts the Zackly resource was expanded last year and shows potential for further growth, especially at depth, the most exciting expansion area is to the east.

ZX‐18020, drilled about 850 meters east of the resource boundary, cut 54.6 meters averaging 2.8 g/t gold, 9.4 g/t silver and 0.6 percent copper, including a 0.3-meter (one foot) section from 56.7 meters averaging 27.3 percent copper, 2.5 g/t gold and 82.5 g/t silver.

ZX‐18024, drilled about 40 meters north of hole 20, cut 46.7 meters of 3.1 g/t gold, 0.6 percent copper and 3.3 g/t silver from a depth of 37 meters. This thick intercept included a 21.7-meter higher grade zone that averaged 5.2 g/t gold, 0.8 percent copper and 4.1 g/t silver from 59 meters.

The 2018 program also hit the skarn between the eastern boundary of the resource and hole 20, indicating that continued drilling could trace a connection.

PolarX Ltd.

Hole ZX-18023, drilled 350 meters east of the currently defined Zackly deposit and 500 meters west of ZX-18020, cut 9.3 meters of magnetite skarn containing 3.3 percent copper, 2.3 g/t gold and 19.7 g/t silver.

ZX‐18025 cut 11.4 meters of skarn mineralization with visible copper sulfides about 40 meters below ZX-18023.

PolarX said it has consistently observed a close association between copper, gold and magnetite in the drilling. The detailed aeromagnetic survey carried out last fall, which can trace the magnetite, has greatly improved the company's understanding of the continuity of mineralization, particularly to the east of the current resource.

With this improved understanding, the company plans to test a strong structure evident in the magnetic data that extends for 500 meters between holes ZX‐18020 and ZX‐18023.

–SHANE LASLEY