‘Larger than anticipated’: Underground drilling at Hillgrove’s Kanmantoo copper mine extends mineralisation

Underground drilling at Hillgrove’s Kanmantoo mine has extended the continuity of the Spitfire and South West Kavanagh mineral systems
Results indicate the Spitfire mineral zone extends well beyond the current geological model
Drilling is continuing as part of the stope definition drilling

Special report: An additional 30 holes have been drilled at the Spitfire West mineral system within Kanmantoo since the last update in November 2023, extending mineralisation to more than 250m vertically.

Hillgrove Resources (ASX:HGO) is up 45% over the past six months after reopening the Kanmantoo mine in South Australia this year.

Having started development on the restart in the middle of last year at $12,500/t (AUD) copper, at current prices it says the mine could deliver an additional $40m per annum in cash flow and potentially reduce its cut-off grade.

Drilling is continuing to provide input into stope planning and development designs.

Spitfire zone extend well beyond the current geological model

The latest results have extended the continuity of the Spitfire and Southwest (SW) Kavanagh mineral systems returning results such as:

40m at 1.38% copper from 74m;
36m at 1.78% copper, 0.15g/t gold from 175m;
1m at 1.38% copper from 87m; and
16m at 1.05% copper from 90m.

So far, infill underground drilling has followed the previously reported 45m at 1.19% copper intersection in Spitfire that was over 100m away from any previously reported hole.

The program intersected several previously unidentified higher-grade copper breccias in both Spitfire and SW Kavanagh.

Results indicate that the Spitfire mineral zone extends well beyond the current geological model and remains open at depth.

To date, 72 drill holes have been drilled into Spitfire while another 15 have been drilled into SW Kavanagh.

Opportunity to bring both lodes into mine plan

“Spitfire was initially considered to be a modest mineral zone which extended over ~50m vertically, however the recent drilling confirms that the Spitfire lode is far larger than initially anticipated and now extends more than 250m vertically and remains open at depth,” HGO CEO and managing director Lachlan Wallace says.

“SW Kavanagh is also looking positive with a number of previously unknown high grade copper breccia zones being identified in the recent 12-hole drilling program.

“As development extends and deeper drill platforms are established, we will continue to chase both the Spitfire and SW Kavanagh mineral system at depth,” he says.

“The close proximity of the Spitfire and the SW Kavanagh lodes to the current underground decline development provides an opportunity to bring the extensions of these lodes into the mine plan for modest incremental cost.”

Nine lodes remain open at depth

Wallace says the strike rate of 62 intersections of significant copper-gold mineralisation from only 42 holes is “exceptional”.

“It reflects the high degree of down dip continuity of the mineral lodes,” he says.

“Given there are there are nine known mineral lodes that remain open at depth on the permitted mining lease, this strike rate positions the company for an exciting future through exploration growth.”

This article was developed in collaboration with Hillgrove Resources , 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.