Parys Mountain Morfa Dhu Zone Mineral Resource Estimate (MRE)

The Challenge / The Scope:

Micon has been working with Anglesey Mining on their Parys Mountain Project since 2006, providing ongoing support through various phases of project development. This work has included the preparation of a Scoping Study in 2017 and a Preliminary Economic Assessment (PEA) in 2021, including comprehensive reviews of the project’s geology and mineralisation, mineral resources, mining, metallurgical testwork, and processing and associated economic analyses.

In 2023, Micon was commissioned to prepare an updated Mineral Resource Estimate (MRE), incorporating results from the latest 2022 drilling campaign on the Morfa Dhu Zone to assess the viability of the Cu-Pb-Zn-Au-Ag sulphide deposits.

Micon’s Approach:

Micon first reviewed and assessed the QAQC data for the new infill drilling to confirm its suitability for use in resource modelling. The geological wireframes, provided by the client, were validated to ensure they appropriately captured the extent of potentially mineralised material. This process involved cross-referencing the wireframes with assay grades, lithological logs, and broader geological interpretations. Within these geological wireframes, Micon constructed grade domain wireframes to distinguish between high-grade mineralisation, lower-grade zones, and internal waste, thereby providing a solid framework for grade estimation.

Ordinary Kriging was used to interpolate copper, lead, zinc, gold, and silver grades into a rotated block model in three passes. For each pass, search ellipse parameters were adjusted to reflect increasing search distances, and restricted neighbourhood parameters were employed to limit the influence of isolated high-grade assays and reduce the risk of grade smearing. The block model was then validated using a combination of visual inspection and statistical analysis, including comparisons against de-clustered composite data and swath plots. Bulk density was estimated through a regression model based on interpolated copper, lead, and zinc grades, allowing for spatially variable density values that reflect the mineralisation characteristics.

Mineral Resources were classified as Measured, Indicated, or Inferred in accordance with the JORC Code (2012), based primarily on drill hole spacing and the continuity of geological and grade data. The final MRE incorporated a Net Smelter Return (NSR) cut-off grade of US$45.15/t to meet the requirement for reasonable prospects for eventual economic extraction (RPEEE). Tonnages and grades were further constrained by applying diluted stope shape wireframes, providing a realistic basis for future mine planning and project evaluation.

Results:

Micon declared Measured, Indicated and Inferred Mineral Resources for the Morfa Dhu Zone. The Measured and Indicated Mineral Resources totaled 5.3 Mt (23% Measured and 70% Indicated) and contained 213,000 t of combined Zn/Pb/Cu, 4.8 Moz silver and 48 koz gold, including 1.6 Mt at 2.5% CuEq in the Engine Zone.

The updated MRE will provide the Client with a foundation for the Project Pre-Feasibility Study, which will incorporate an optimized mine design layout, results from recently commenced metallurgical testwork and preliminary engineering designs for a dry-stack tailings facility.

The Client intends to undertake a similar resource update process for the large Northern Copper Zone including additional drilling.