Plutonic and Trident Mineral Resource & Ore Reserve Update

Key Points

• In June 2023, Catalyst acquired two companies to complete a consolidation of the Plutonic Gold Belt, a belt situated in northern WA
• Previous owners of the belt had estimated Mineral Resources and Ore Reserves however, Catalyst felt a different estimation approach was needed
• Since taking control, Catalyst has been undertaking this re-estimation process
• These global Plutonic Resources include Resources for both the underground mine at Plutonic as well as the satellite development project, Trident
• Mineral Resources and Ore Reserves for the Plutonic Main deposit are:
  • Indicated Resources: 17.2Mt at 2.9g/t Au for 1,592,000oz
  • Inferred Resources: 0.7Mt at 2.6g/t Au for 62,000oz
  • Reserves: 5.2Mt at 2.9g/t Au for 490,000oz
• Resource and Reserve estimation has still not been undertaken by Catalyst on Plutonic East and the Hermes Area 
• Mineral Resources for Trident are:
  • Indicated Resources: 1.6Mt at 5.0g/t Au for 257,000oz
  • Inferred Resources: 2.6Mt at 3.0g/t Au for 251,000oz
• Trident resources have increased by 24% but grade has been reduced from the Vango estimates 
• Trident Definitive Feasibility Study is well progressed; Reserves expected to be released with this study in 2024
• Release of this updated Mineral Resource estimate is an important step in Catalyst’s process to rebuilding the foundations of the Plutonic Gold Belt. This release follows Catalyst’s installation of a new operating team at the Plutonic gold mine. The combination of the two is responsible for the improved operating performance of the mine

PERTH, Australia, Dec. 6, 2023 /PRNewswire/ – Australian gold producer, Catalyst Metals Limited (Catalyst or the Company) (ASX: CYL) is pleased to provide an updated Mineral Resource & Ore Reserve statement for its Plutonic Gold Mine, and an updated Mineral Resource for the Trident deposit.   

Importantly, the updates presented in this release relate to the Plutonic Main and Trident deposits only.  The Plutonic Gold Belt hosts numerous open pit and underground deposits that have previously been estimated by other competent persons. Those deposits are yet to be re-estimated.

Catalyst’s MD & CEO, James Champion de Crespigny, said: “We are pleased to have this important body of work behind us. Such estimates are the foundation of any operation. This update provides our team with the comfort to execute on the mine plan.

The updated Trident Resource estimate is different than expected. It now reflects what Catalyst believe is an improved approach to estimating such a deposit, updated drilling and a lower cut-off grade in this higher gold price environment. This Resource will form the basis of the pending Trident Definitive Feasibility Study.  

That study is well progressed and the Company remains committed to its development as quickly as possible given its high grade and the latent mill capacity that currently exists at Plutonic.

Catalyst took control at Plutonic a little over five months ago and in that time there have been considerable changes. This is but another step in that transition plan as we set the company up for 2024.”

Plutonic Underground Mineral Resources

The Mineral Resource & Ore Reserve sit within the existing mining footprint and do not include virgin zones.  Importantly, Table 1 below refers specifically to the Plutonic Main orebody and does not include any of the satellite deposits within the consolidated tenement package.  The previously reported NI 43-101 Ore Reserves and Mineral Resources for the Plutonic Operations included satellite deposits such as Plutonic East, Plutonic West, Hermes and Perch.  These remain NI 43-101 compliant, but not JORC compliant. Catalyst will review these estimates in due course.

The Mineral Resources and Ore Reserves for the Plutonic Underground Mine and Mineral Resources for the Trident deposit have been estimated for the first time by Catalyst following the acquisition of Superior Gold and Vango Mining.

Catalyst undertook a comprehensive re-estimation and classification of the entire Plutonic Main deposit Mineral Resources.  This included the Plutonic Main underground and open pit areas.  The previously reported Plutonic Main open pit Mineral Resources have now been incorporated into the Plutonic underground Mineral Resource inventory.  Further work is planned to re-evaluate the Plutonic Main open pit potential.

The re-estimation and classification of the Plutonic Mineral Resources followed an extensive review of the geological and geostatistical behaviour of the Plutonic mineralisation together with mine production reconciliation.  Catalyst has implemented a resource modelling technique that is well suited to estimating highly variable gold mineralisation.  The modelling parameters were optimised so that the final Mineral Resource was well aligned with recent and historic production reconciliation performance. 

The Mineral Resource Estimate (MRE) for Plutonic Underground has been undertaken with a focus on delineating areas of the MRE with Reaonable Prospects for Eventual Economic Extraction (RPEEE).  Catalyst has applied a approach to historic mining depletion to ensure that the inclusion of potential ‘un-mineable’ remnants has been minimised.  In addition, an underground Shape Optimiser (SO) evaluation has been applied to ensure that only cohesive groups of blocks that satisfy RPEEE are included in the MRE.

The previous combined Measured, Indicated and Inferred NI 43-101 MRE as at 31 December 2021 for the Plutonic Main underground and open pit contained 4.97Moz.  Mine production depletion to 30 November 2023 accounts for 123Koz whilst changed modelling methodology, resource classification, historic depletion and RPEEE considerations has accounted for a reduction of 3.2Moz.  A high proportion of the resource reduction is due to a grade reduction from 4.6g/t Au (Measured and Indicated) and 5.2g/t (Inferred) to the current 2.9g/t Au (and 2.6g/t Au for Inferred).  Following is a summary of the Plutonic Underground Mineral Resources, as at 30 November 2023.

Table 1: Plutonic MRE (at 1.5g/t Au cut-off)

Plutonic Underground Ore Reserves

Following is a summary of the Plutonic Underground Ore Reserves, as at 01 January 2024.

Table 2: Plutonic Ore Reserves

As with the Mineral Resources, almost all of the reduction in ounces is due to a reduction of grade from 3.7g/t Au to 2.9g/t Au which is considered to be a more reliable estimate of mine grade going forward.

Trident Mineral Resources

The Trident deposit sits approximately 25km to the north-east of the Plutonic Gold Mine and the planned development in 2024 has been made possible by the recently completed consolidation of the Plutonic Gold Belt.

The estimation approach for the updated Trident MRE was primarily based on domains defined by geological, structural and mineralisation characteristics.  This differs from the previous MRE approach where the continuity and volume of estimation domains were largely subjected to pseudo economic and mining criteria at an elevated cut-off grade.  The Catalyst estimation approach has allowed the full grade-tonnage distribution of the mineralised domains, including additional lower grade material, to be incorporated into the MRE. 

The Trident MRE has been undertaken with a focus on delineating areas of the MRE with Reasonable Prospects for Eventual Economic Extraction (RPEEE).  An underground Shape Optimiser (SO) evaluation has been applied to ensure that only cohesive groups of blocks that satisfy RPEEE are included in the MRE.

In July 2023, Catalyst released a Scoping Study assuming an underground development at Trident, with ore transported and processed through the Plutonic mill (see ASX announcement entitled “Trident Scoping Study demonstrates Plutonic’s potential” dated 19 July 2023).  The Scoping Study utilised the previous Trident MRE (see ASX announcement entitled “Marymia Gold Project Mineral Resource – Updated” dated 22 February 2023).  Catalyst considers that the updated MRE would result in changes to the results published in the Scoping Study.  Updated results will be made available with the release of the DFS which is expected to occur in January 2024.

Following is a summary of the Trident Mineral Resource Estimate, as at 30 November 2023.

Table 3: Trident MRE