Compelling porphyry evidence for Saturn
North of 60 Mining News – April 1, 2019
Last updated 9/25/2020 at 2:32pm
PolarX Ltd. March 25 announced that 3D modelling of magnetic data collected last year provides further evidence of a large porphyry copper-gold target at Saturn, an Alaska Range prospect previously known as Zackly SE due to its proximity to a high-grade skarn deposit on the Australian company's property.
PolarX began its exploration at Alaska Range with expansion drilling at the known Zackly skarn, which 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.
A 3,650-meter drill program carried out last year demonstrates the significant expansion potential of this deposit and provided evidence that a much larger porphyry deposit is likely lurking nearby.
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 ore body. Porphyry deposits, on the other hand, are deposits 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.
The Zackly skarn lies in the middle of a 7.5-mile (12 kilometers) structural corridor that is bookended by two potential porphyry centers – Saturn to the southeast and Mars to the northwest.
While testing southeast extensions of Zackly skarn, the 2018 drill program encountered signs that PolarX was closing in on porphyry mineralization as it stepped out in the direction of Saturn.
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.
In addition to providing evidence that a thick and relatively flat-lying extension of Zackly is found in this direction, the robust copper and gold mineralization has the type veining and alteration commonly associated with porphyry systems.
This evidence was bolstered by the initial data from a high‐resolution aeromagnetic geophysical survey flown last fall, which showed that Saturn has the donut-shaped magnetic pattern typical of a porphyry deposit.
"Every piece of exploration work we do provides more evidence that Saturn is a compelling copper‐gold porphyry target," said PolarX Managing Director Frazer Tabeart.
The 3D inversion modelling of the magnetic data furthers this evidence.
PolarX said the 3D data shows a roughly cone-shaped magnetic body that is roughly 2,000 by 1,000 meters at the top and extends to a depth of at least 3,000 meters, the lower extent of the modelling.
This magnetic body lies under a 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," said Tabeart.
The final piece of evidence will be to tap this text-book example with a drill, which PolarX plans to do with 3,000 meters of drilling to test Saturn and Mars, expected to begin sometime after midyear.
To target this drilling, the Aussie explorer plans to complete an induced polarization (IP) geophysical survey designed to locate the presence of disseminated sulfides associated with the intrusive core and in the surrounding alteration halo at Saturn.
With the magnetic data showing the porphyry target at Saturn angled to the south as it extends to depth, PolarX has staked additional 4,800 acres of claims to cover this plunge as well as a buffer in this direction.
PolarX has secured a contract for the IP survey and plans to carry out the geophysical work as soon as the seasonal snow has melted at the company's Alaska Range project.
The company also plans to continue its expansion of Zackly during the 2019 exploration season with 3,000 meters of drilling focused on the thick zones of high-grade copper and gold tapped beyond the eastern end of the skarn deposit.
Following the end of the field season, the Aussie explorer intends to initiate a preliminary economic assessment or pre-feasibility study for Zackly.