Lefroy’s Burns prospect is looking increasingly like a large intrusion-related gold-copper system after drilling outlined gold-copper-silver zone hosted within basalt.  

This follows the receipt of assay results from the final 12 reverse circulation holes drilled at Burns earlier this year that includes a broad intersection of 62m grading 0.47 grams per tonne (g/t) gold and 0.45 per cent copper from a depth of 68m to the end of hole.

The final 30m returned 0.57g/t gold, 0.63 per cent copper and 3.9g/t silver in LEFR271

Lefroy Exploration (ASX:LEX) noted that this mineralisation is hosted in magnetite altered basalt with no associated quartz veining or foliation.

Adding interest, the same basalt has been intersected in diamond core drilled down dip of LEFR271 with assays still pending – in recent holes drilled to the north and south of LEFR271 that includes a 16m zone at 0.74g/t gold and 0.33 per cent copper from 100m; and in a diamond hole drilled by Octagonal Resources Ltd in 2014 about 60m to the northwest.

The basalt is a component of the Burns mineral system and additional to the thick high-grade gold porphyry hosted intersection previously reported in hole LEFR260 located about 100m to the east.

lefroy exploration cross section burns basalt
Schematic geological cross section highlighting LEFR271. Pic: Supplied

“The intersection in LEFR271 and others within the basalt host rock to the west of the high-grade gold copper intercept in LEFR260 adds another alteration style and mineral assemblage to the Burns gold copper system,” managing director Wade Johnson said.

“This is an important development and adds a new dimension to this exciting new mineral system in the Eastern Goldfields where we are very keen to get back drilling later this month.”

Lefroy added that the varying alteration styles in contrasting host rocks, along with previously reported native copper hosted in fresh basalt and broad magnetite anomaly system, provides support for a large primary intrusion related gold-copper-silver system at Burns.

Next steps

The company expects to receive in late March assay results for four diamond holes that evaluated the basalt zone.

It also expects results from more detailed 1m samples from anomalous 4m composite RC samples in the same period.

Planning and scheduling for follow-up diamond drilling to validate and extend the mineralisation at LEFR260 is also underway with work to begin soon.

This will focus initially on a diamond twin to LEFR260 that will be followed by a hole to evaluate the system about 50m below.


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.