Chalice Mining Limited (ASX: CHN) has unveiled an updated Mineral Resource Estimate for the Gonneville Deposit, the first discovery at its wholly-owned Julimar Nickel-Copper-Platinum Group Element (PGE) Project, located ~70km north-east of Perth in Western Australia.
The large-scale Gonneville magmatic PGE-Ni-Cu-Co-Au sulphide deposit, which was initially discovered in early 2020, is located on Chalice-owned farmland. Over the last three years, more than 1,000 drill holes for ~275,000m have been completed to define the deposit which, remarkably, still remains open to the north-west and down-dip.
Since the previous Resource update in July 2022, drilling at Gonneville has largely been focused on infill and extensional drilling at the northern end of the Deposit, as well as extending high-grade shoots at depth. A total of 260 new drill holes have been incorporated into this Resource update.
The drilling and re-modelling have resulted in a ~50% increase in the contained nickel equivalent metal relative to the July 2022 estimate.
This increase is due to:
- Extensional drilling defining new mineralization along strike and down-dip of the previous Resource pit shell.
- The Resource pit shell increasing in size in the northern portion of the deposit as a result of infill and extensional drilling defining additional mineralization.
- Pit optimisation parameters being updated to incorporate revised long-term metal prices as well as new metallurgical testwork on lower-grade disseminated sulphide mineralization, and revised processing and mining costs resulting in a slight reduction in the Resource cut-off grade from 0.40% NiEq to 0.35% NiEq. This has also reduced the strip ratio to ~1.6 (previously >2).
The inclusion of additional mineralization in the underground category, based on the potential for bulk underground mining (i.e., sub-level caving). The July 2022 Resource only included high- grade underground areas within Mineable Stope Optimiser (MSO) shapes.
A programme of close-spaced RC drilling on a nominal 10m x 10m pattern was completed over an area of ~150m x 75m (within the expected Starter Pit area) to determine the short-range grade variability and confirm the geological interpretation of the high-grade G1/G2 zones. This detailed drilling has upgraded the Resource in this area to Measured classification. Step-out drilling has also continued to evaluate the broader extent of mineralization, typically on 80-200m spacing.
The Resource includes a mix of oxide, transitional and sulphide mineralization. The sulphide mineralization in-pit is reported at two different cut-off grades (0.35% and 0.60% NiEq) to highlight the scale and development optionality the Deposit affords.
The robust nature of the Resource is demonstrated by the grade-tonnage curve, which highlights the significant quantity of pit-constrained sulphide mineralization at higher cut-off grades. Note that the grade-tonnage curve for the Resource includes material classified as Inferred, where data is insufficient to allow the geological grade and continuity to be confidently interpreted. Note that the grade-tonnage curve excludes oxide and underground resource domains.
The significant higher-grade component of the Resource provides excellent optionality for any future development and could potentially materially improve project economics in the initial years of the operation. This remains a focus of the ongoing development studies.
Drilling is continuing at Gonneville outside the Resource, with assays currently pending for 52 drill holes.
Two diamond rigs continue to test for extensions of high-grade mineralization at depth. The Deposit remains open beyond a depth of ~800m, with step-out drilling indicating that mineralization extends to at least ~1,100m. This points to a significant underground resource growth opportunity.
“The ~50% increase in the Gonneville Resource to ~3Mt of nickel equivalent is quite a remarkable achievement for the Chalice team given it is barely three years since the discovery of the Julimar Complex. Gonneville is now the third largest undeveloped nickel sulphide resource in Australia,” Managing Director and CEO, Alex Dorsch, said.
“The latest numbers continue to demonstrate the world-class endowment, scale and quality of the Gonneville Deposit, while also highlighting a compelling picture of upside along the remaining ~28km strike length of the Julimar Intrusive Complex.
“Apart from further increasing the contained metal, this Resource update has also delivered a significant increase in the higher-confidence Indicated Resource component – which now represents ~60% of the open-pit Resource. Importantly, 95% of the Resource above a depth of 200m is now classified as Indicated, which represents a major de-risking step for the Project.
“This uplift in the higher confidence Resource categories includes the tightly spaced drilling that was undertaken in the Starter Pit area to determine the short-range grade variability and confirm the geological interpretation of the high-grade G1/G2 zones. This work has been very successful, resulting in the establishment of Measured Resources in this area and increasing our confidence in the robustness of the overall Resource model at 40m drill spacing.
“The continued growth in the higher-grade sulphide component – both in an expanded open pit optimization and, significantly, in a wide-open bulk underground category, further enhances the significant development optionality of the Deposit – with the updated March 2023 MRE to be incorporated into the ongoing Scoping Study work.
“Because of the sheer size and quality of the Resource and the significant level of inbound inquiries we have received from a range of downstream, trading and end-user parties, the Board has decided to commence a formal strategic partnering process for the Julimar Project. This process will consider a broad range of potential transactions with the aim of maximizing shareholder value and will continue in parallel with the ongoing Scoping Study.
“It is also evident from recent exploration results that there is enormous growth potential both at depth at Gonneville and along the effectively untested Julimar Complex to the north. While we already have a tier-1 scale deposit which has the potential to underpin a world-class, long-life green metals project, the Resource base is expected to continue to grow. Our multi-pronged exploration campaign will therefore continue over the coming months as we work to unlock the full potential of the 30km long Julimar Complex.
“This means that shareholders and stakeholders can look forward to several parallel news-flow streams in the months ahead – from ongoing development studies, from the strategic partnering process, and from ongoing exploration aimed at further expanding the Resource and unlocking new discoveries.”
The Julimar Project is favourably located, with access to established road, rail, port and high-voltage power infrastructure nearby, plus access to a significant ‘drive-in, drive-out’ mining workforce in the Perth surrounds
For further information please visit: https://chalicemining.com/
