Lefroy drills into Burns to discover signs of multiple porphyry intrusions
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Lefroy’s Burns discovery near Kalgoorlie is shaping up into a significant gold-copper system after drilling extended the anomaly’s length to 900m which remains open.
Final assays from a major 577 hole aircore program totalling 21,485m over the broader Lake Randall area in its Lefroy gold project returned infill hits such as 12m at 3.43 grams per tonne (g/t) gold and 0.2% copper from a depth of 40m including 8m at 4.89g/t gold and 0.22% copper from 44m to end of hole in LEFA1498.
Along with multiple infill holes which also intersected gold mineralisation, Lefroy Exploration (ASX:LEX) now has the framework for a follow up land and lake-based RC drill program to deliver a maiden shallow resource.
Separately, early stage drilling at the Neon target about 3,500m to the northwest has intersected diorite porphyry similar to Burns.
Results such as 11m at 0.24g/t gold from 16m to EoH (LEFA1319), 4m at 0.5g/t gold from 16m (LEFA1332) and 20m at 0.24g/t gold from 16m (LEFA1387) has resulted in the definition of a broad 1km by 1km intrusion-related gold anomaly at Neon.
More importantly for the company, the results demonstrate the larger footprint of the gold mineralised diorite porphyry interpreted as part of a larger Burns Igneous Complex which consist of multiple porphyry and associated comagmatic intrusions that could each host gold-copper mineralisation.
“The new results from Burns, and now the emerging Neon prospect from aircore drilling beneath Lake Randall, add further support to the growing lateral dimensions of mineralisation surrounding the Burns Intrusion,” managing director Wade Johnson says.
“We are now very keen and prepared to commence the deep diamond drill hole at Burns to test the vertical extent of the system which is about to get underway.”
The Burns prospect is located on the eastern margin of the Burns felsic intrusion in Lake Randall, which is itself situated within the wholly-owned Lefroy gold project about 50km southeast of Kalgoorlie.
While the intrusion does not outcrop, it features a distinctive annular aeromagnetic and gravity geophysical signature with three parallel linear magnetic features – Lucky Strike, Havelock and Erinmore – appearing to radiate out to the north.
Lefroy is working towards establishing the association between the larger Burns intrusion, the magnetic anomalies and the diorite porphyry intrusions intersected at Burns, which it has yet to fit into a known model.
That this mystery has been intriguing enough for the company to receive a $560,000 R&D tax refund from the Federal Government for the 2020-21 tax year speaks volumes about how much the company has pumped into it.
There’s good reason to do so, given the potential to guide further exploration within the system as evidenced by the results from the Neon target.
Results from the major lake-based AC drilling program validate the targeting criteria used by the company for the methodical staged drilling approach in this new gold-copper intrusion related mineral system.
With the results at Neon demonstrating the larger footprint of the gold mineralised diorite porphyry, Lefroy plans to carry out further lake-based aircore drilling on Lake Randall to follow up anomalies generated from the recent program and additional new targets.
Interpretation of the gold and bottom of hole multi-element data from this large program is ongoing and will provide the baseline geochemical framework to provide vectors to higher priority targets.
This has included the positioning for a deep (+1km) EIS funded diamond drill hole at Burns, which is about to commence.
Planning is also underway for a program of lake-based RC drilling to evaluate the regolith (oxide) anomalies in Lake Randall immediately north of Burns is underway.
This drilling is scheduled to commence in August and will form the basis of a maiden resource.
This article was developed in collaboration with Lefroy Exploration, a Stockhead advertiser at the time of publishing.
This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.