Drilling has confirmed depth extensions to the intervals of altered porphyry that is host to high-grade copper gold mineralisation at Lefroy’s Burns Copper Gold prospect.

And that’s a good thing as it indicates that Burns hosts a potentially larger zone of mineralisation, with similarities to an intrusion-related system.

Two diamond holes drilled by Lefroy Exploration (ASX:LEX) have intersected significant mineralisation/alteration zones that confirmed at least 55m vertical depth continuity of the host porphyry where the discovery hole returned a 38m intersection grading 7.63 grams per tonne (g/t) gold and 0.56 per cent copper from a depth of 134m in hole LEFR260, reported in February 2021.

Drilling also discovered new, vertically continuous zones of mineralisation and alteration while establishing that the Eastern Porphyry is over 100m in true width.

While the first hole LEFD004 had twinned and extended the discovery hole, the second hole – OBURCD025 – that was drilled to evaluate the host rocks 55m below the mineralised zones in LEFD004, intersected a 189m downhole interval of the Eastern Porphyry.

This hole hit 35m of strong mineralisation from 201m including 17m of strong altered porphyry with magnetite veining, which is the expected position of high-grade position in the discovery hole, along with a further 22m of altered porphyry from 269m.

The company noted that the result reinforces its initial interpretation of the Burns copper-gold prospect as being a multi-stage mineral system, with the final magnetite sulphide (chalcopyrite) event mineralising both the porphyry and the adjacent basalt host rocks.

More porphyry drilling

Lefroy is now drilling the third hole in its 14-hole program.

This hole will evaluate the Eastern Porphyry a further 60m vertically beneath hole OBURCD025, providing additional important constraints to the system to about 275m vertical depth from surface.

It will also provide baseline geological and assay results to support evaluation of the system on step out sections to the north and south.

Assays from LEFD004 and OBURCD025 are expected in late June.




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.