Galileo Mining Ltd’s (ASX:GAL) petrography results from reconnaissance drilling have identified nickel prospective rocks beneath shallow cover in the highly prospective Fraser Range region of WA.
The drilling results, combined with magnetic data, show three intrusions which have been named Think Big, Backwood and Green Moon.
These intrusions have the potential to host magmatic nickel mineralisation under shallow cover rock ranging from 17 metres to 92 metres below surface.
A high-powered ground electro-magnetic (EM) survey is being planned to cover the newly identified intrusions with the intention of defining zones of nickel mineralisation.
Unexplored nickel potential
Managing director Brad Underwood said the recent $5 million placement had allowed the company to expand the amount of exploration in the Fraser Range.
“We have substantially increased the search space around our Lantern prospect and have the funds to effectively explore the entire area over the next six to 12 months.
“Our Fraser Range ground has never before been explored for nickel and the significant chance of a high-value discovery makes this is an exciting time to be investing in the area.”
Petrography results
The results from bottom-of-hole aircore drill holes show the composition of the target basement rock beneath sedimentary cover material.
For the drill holes completed at the Green Moon, Backwood and Think Big prospects, the cover rock varied between 17 metres and 92 metres.
Samples of fresh rock (or near to fresh) from the Proterozoic basement were sent for petrographical analysis where the samples were sliced, polished and described under the microscope.
Minerals occurring within the samples and their relationship to each other were then observed to determine their provenance and prospectivity for nickel sulphide mineralisation.
Drill holes at these three prospects were found to have intersected mafic or ultramafic rocks.
Similar exploration methodology to Nova
These rocks are critical in exploration for the type of deposits described as 'magmatic nickel sulphides' which occur in the Fraser Range.
The best-known example of this magmatic nickel sulphide is IGO Ltd’s (ASX:IGO) operating Nova Nickel Mine, where nickel mineralisation is intimately associated with mafic and ultramafic intrusions.
Discovery of the Nova deposit utilised ground EM surveys to define key target locations and these were conducted after drilling showed disseminated sulphides in mafic intrusive rocks.
Galileo is following a similar exploration methodology with drilling used to demonstrate the occurrence of nickel prospective rocks prior to EM surveying.
EM surveying at Galileo’s new prospects aims to directly detect zones of sulphide mineralisation.
Lantern South Prospect
Aircore drilling is progressing well at the Lantern South prospect with over 5,500 metres completed of a planned 8,000-metre program.
This is following up on initial RC drilling results of 12 metres at 0.38% nickel and 0.33% copper in LARC003.
The occurrence of mineralisation at Lantern South shows the potential of the rocks in the area to host nickel-copper sulphides.
Upcoming programs
Work programs at the Think Big, Backwood and Green Moon prospects include EM surveying of prospective zones aiming to define conductors for drill testing as well as additional air-core drilling.
Reverse circulation (RC) and diamond drill (DD) testing of targets defined by EM surveying and shallow drilling will also continue.
Upcoming work programs at the Lantern prospect include:
- Completion of aircore drilling program (5,500 of 8,000 metres drilled to date);
- Fixed loop electro-magnetic (FLEM) surveying of prospective zones defined from the current air-core drilling and from the 2019 MLEM survey; and
- RC and DD testing of targets defined by EM surveying and shallow drilling.
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