Hillgrove Resources has updated its Kanmantoo Mine exploration targets, identifying significant copper-gold potential and planning an extensive 19,000-metre diamond drilling campaign in 2025 to expand its resource base.
- Exploration Target updated to 25-40 million tonnes at 0.7%-1.4% copper and 0.05-0.5 g/t gold
- High-potential down dip extensions and new lode targets identified near existing resources
- Five untested underground targets within 500 metres of processing plant
- Over 19,000 metres of diamond drilling planned with a third underground rig mobilised in Q2 2025
- Exploration Target excludes recently doubled 2024 Mineral Resource Estimate
Context and Significance of the Update
Hillgrove Resources Limited (ASX:HGO) has released a comprehensive update on its exploration targets at the Kanmantoo Mine, located 55 kilometres southeast of Adelaide in South Australia. Building on a remarkable 96% increase in contained copper and a 138% rise in contained gold reported in its 2024 Mineral Resource Estimate (MRE), the company has now delineated a new Exploration Target ranging from 25 to 40 million tonnes. This target carries a copper grade between 0.7% and 1.4% and gold grades from 0.05 to 0.5 grams per tonne, underscoring the significant potential for resource expansion in the near term.
Exploration Targets and Strategic Focus
The updated Exploration Target focuses on down dip extensions of known mineralisation and the discovery of new lodes, particularly around the Stella and South Kanmantoo zones. Hillgrove has identified eleven high-potential copper-gold target zones, including four targets directly below the 2024 Mineral Resource and five untested underground targets, three of which have surface expressions. All targets lie within 500 metres of the Kanmantoo processing plant, positioning them strategically for efficient development.
CEO and Managing Director Bob Fulker highlighted the prioritisation of these targets following the recent resource growth, emphasizing the company’s commitment to organic expansion. The exploration strategy leverages underground development to establish new diamond drill platforms, enabling precise targeting of extensions at Valentines, Critchley, Matthew, and other proximal lodes.
Drilling Program and Operational Plans
To test these promising targets, Hillgrove plans an ambitious drilling campaign exceeding 19,000 metres of diamond drilling in 2025. This includes mobilising a third underground diamond drill rig in the second quarter to complement existing rigs focused on grade control and resource expansion. The drilling will not only aim to extend mine life by targeting down dip and strike extensions of the Nugent and Kavanagh lodes but also explore new lodes such as Valentines, Critchley, and Paringa, which are close to planned mine infrastructure.
Data from these drilling programs will feed into the company’s annual Mineral Resource and Ore Reserve Statement scheduled for release in Q4 2025, incorporating both 2024 and 2025 drilling results. This iterative approach reflects Hillgrove’s methodical strategy to refine geological understanding and optimise resource modelling.
Technical and Geological Insights
The Kanmantoo deposit is characterised by structurally controlled epigenetic copper-gold mineralisation within quartz-biotite schists, with mineralised zones exhibiting steep easterly dips. Hillgrove’s extensive drill hole database, spanning over two decades and depths up to 800 metres, reveals significant potential for higher-grade zones extending beneath and along strike of historical open pits. However, drilling below and along strike remains sparse, underscoring the importance of the planned exploration drilling to unlock these deeper targets.
The company’s rigorous sampling, assay, and QAQC protocols, including the use of certified reference materials and field duplicates, provide confidence in the reliability of the geological data underpinning the Exploration Target. Hillgrove’s on-site laboratory and external assay facilities maintain stringent quality controls, ensuring robust data for resource estimation.
Operational Context and Future Outlook
Kanmantoo Mine, with its existing infrastructure including a 3.6 million tonne per annum processing plant and permitted tailings storage, restarted underground operations in 2023 and achieved first copper production in February 2024. The proximity of new exploration targets to this infrastructure offers a clear pathway to potentially extend mine life and enhance production profiles.
While the Exploration Target remains conceptual and is not yet classified as a Mineral Resource under JORC standards, the update signals a proactive approach by Hillgrove to capitalise on near-mine opportunities. The company’s forward-looking statements caution that uncertainties remain, but the strategic drilling program and geological insights position Hillgrove well to convert exploration success into tangible resource growth.
Bottom Line?
Hillgrove’s aggressive drilling plans and expanded exploration targets at Kanmantoo set the stage for a pivotal resource update later this year.
Questions in the middle?
- Will the 2025 drilling confirm extensions sufficient to upgrade the Exploration Target to a Mineral Resource?
- How will commodity price fluctuations impact the economic viability of newly identified lodes?
- What timelines and capital requirements will Hillgrove face to develop these new underground targets?