PolarX Ltd (ASX:PXX) (FRA:PX0) has confirmed that the Zackly SE prospect is another compelling copper-gold porphyry target within the Alaska Range project in Alaska.
A new high-resolution aeromagnetic survey has more clearly defined the target and has highlighted a 12-kilometre-long mineralised structural corridor from Zackly SE to the Mars porphyry target.
This new data will greatly assist targeting drilling extensions to the 47-55 metre-thick, near-surface high-grade mineralisation discovered in two holes 850 metres east of the existing Zackly inferred resource.
“An outstanding district”
PolarX managing director Dr Frazer Tabeart said the results showed Zackly was an outstanding district.
“The combination of these results, PolarX’s drilling to date and the well-documented association of skarn mineralisation such as Zackly with porphyry copper-gold systems makes Zackly SE a compelling porphyry target.
“Our closest drill intercepts of up to 55 metres width at 2.8 to 3.1 g/t gold and 0.6% copper clearly vector towards this target, demonstrating its potential,” he said.
Geological map for the project showing the outline of the high-resolution aeromagnetic survey.
The helicopter survey collected magnetic data on 50-metre line spacing at an average height of 33 metres above the ground over most of the Stellar property in the northeast section of the Alaska Range project.
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Survey results are considered important because they show several intrusions at Zackly SE which are in turn surrounded by a broad zone of magnetite destruction.
These key characteristics are common in many higher-grade major porphyry deposits.
Improvement in resolution
The new data provides a significant improvement in resolution compared to the previously available regional aeromagnetic data.
Comparison between the original data (left) and the new high-resolution survey.
Of note is a very prominent mineralised structural corridor which extends from the Mars copper-gold target to the Zackly SE porphyry target, a distance of about 12 kilometres.
The high-grade skarn mineralisation at Zackly occurs on the northern boundary of this structural corridor.
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PolarX believes the thick, near-surface, high-grade nature of mineralisation in the two holes may allow accumulation of additional resource tonnes and metal inventory with further drilling.
Rapid extension of this will be aided by the new high-resolution magnetic data.
Zackly’s inferred resource stands at 41,000 tonnes of copper, 213,000 ounces of gold and 1.5 million ounces of silver from the surface over a strike length of 1-kilometre.
The nearby Caribou Dome deposit hosts a JORC-compliant resource of 2.8 million tonnes at 3.1% copper.
The high gold grades and thick, relatively flat geometry of mineralisation could be suitable for low-cost open-pit extraction, subject to an economic resource being established through further drilling and feasibility studies.
Work program
PolarX is expecting to receive results from a number of holes as well as soil sampling assay results and geological mapping from the Mars porphyry copper-gold target.
Rock chip sampling and geological mapping results are also expected from the Moonwalk Tintina-style gold target.
Further modelling of the high-resolution magnetic data is being carried out to refine drill targets at Zackly, Zackly SE and Mars.