The mining newspaper for Alaska and Canada's North
North of 60 Mining News – February 8, 2019
PolarX Ltd. Jan. 29 reported that the final assays from the 2018 drill program at its Alaska Range project continues to tap copper-gold-silver mineralization below the resource boundaries of the Zackly skarn deposit.
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.
This resource is a good start toward one of PolarX' goals for the Alaska Range project – build enough metals inventory to support a feasibility study for an economically viable mining operation at Zackly.
Toward this objective, the Australia-based explorer completed 3,560 meters of drilling during the 2018 summer field season in Alaska.
Drilling deeper
One area that remains open for resource expansion is extending the skarn deposit at depth.
PolarX' 2018 drill program enjoyed early success in demonstrating the copper-gold-silver mineralization extends deeper.
Hole ZX-18018, reported in August, cut three zones of copper‐gold mineralization 100 meters below the nearest hole in the current JORC-compliant resource.
From a depth of 261.6 meters, this hole cut 25.5 meters averaging 0.6 percent copper, 1.5 grams per metric ton gold; and 5.5 g/t silver; 13.9 meters of 0.6 percent copper, 1.1 g/t gold and 4.7 g/t silver from 300.8 meters; and 4.7 meters of 1.3 percent copper, 2.1 g/t gold and 10.6 g/t silver from 326.1 meters.
In the final batch of 2018 results, reported on Jan. 29, PolarX reported results from ZX‐18032, another hole drilled under the resource of Zackly.
Drilled about 250 meters west of ZX-18018, hole ZX‐18032 cut 6.7 meters averaging 1.2 percent copper, 0.5 g/t gold and 6.9 g/t silver.
ZX‐18030, which tapped Zackly closer to the surface on the same cross‐section as ZX‐18032, cut 5.8 meters of 0.8 g/t gold, 0.5% copper and 4.9 g/t silver from 128.3 meters.
Z-07-81, a historical hole about 30 meters above ZX‐18032, cut 7.9 meters of 2.05 percent copper, 2.55 g/t gold and 22 g/t silver.
PolarX said these results clearly demonstrate the potential for the Zackly Resource to extend further at depth, where it has yet to be closed off by drilling.
Eastward expansion
While the 2018 program shows that that outcropping skarn mineralization continues deeper, the most exciting expansion area is along strike 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.
PolarX said the high gold grades and thick, sub‐horizontal geometry of this mineralization encountered in these two holes could be suitable for low cost open‐pit extraction, subject to an economic resource being established through further drilling and feasibility studies.
While the company has not yet finalized its 2019 program for the Alaska Range property, the thick zones of near surface copper-gold mineralization is expected to be a priority target for drilling.
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.
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.
Drilling Zackly SE, Mars
While Zackly is high-grade and showing size potential, it may not be the biggest prize the Alaska Range property has to offer.
The Zackly skarn lies in the middle of a 7.5-mile- (12 kilometers) long structural corridor that extends from the Mars prospect on the northwest end to Zackly SE prospect on the southeast end. These prospects that bookend the corridor show signs of hosting porphyry gold-copper deposits. While typically lower grade, this type of deposit has the potential to be very large.
The robust gold and copper mineralization encountered to the east of the Zackly deposit, including the thick zone intersected in hole 20, has the type veining and alteration commonly associated with porphyry systems.
A high‐resolution aeromagnetic geophysical survey flown last fall over most of the Stellar property has bolstered the notion that Zackly SE could be hiding a buried porphyry deposit.
"Porphyry copper deposits often, but not always, appear as magnetic highs, with alteration halos usually manifested as annular (donut-shaped) or open-ring peripheral magnetic lows," the United States Geological Survey inked in a report on porphyry deposits.
This classic signature is evident at Zackly SE.
"The combination of these results, PolarX' drilling to date and the well‐documented association of skarn mineralization such as Zackly with porphyry copper‐gold systems makes Zackly SE a compelling porphyry target," said PolarX Managing Director Frazer Tabeart.
The Mars target at the other end of corridor may be even more promising.
A 2,000- by 1,500-meter copper-gold-molybdenum soil anomaly at Mars, coupled with an induced polarization (IP) geophysical anomaly identified 100 to 150 meters below the surface, provides intriguing evidence of another potential porphyry gold-copper system to the northwest of Zackly.
"These results provide several pieces of key evidence which, when combined, strongly support our view that Mars is an exceptional, high‐priority target," said Tabeart. "They show that multi‐element anomalism in soil and rock‐chip geochemistry is spatially coincident with an IP anomaly and an interpreted intrusive cluster."
Both Mars and Zackly SE are expected to be targeted with exploratory holes during the 2019 season.
–SHANE LASLEY
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