More Nickel in Updated Black Swan Disseminated Mineral Resource Poseidon Nickel announced a revised Mineral Resource Estimate (MRE) for the Black Swan disseminated sulphide deposit, underscoring progress in operational strategy and resource confidence. The update supports the company’s “Fill the Mill Strategy,” which aims to maximize utilization of the existing 2.2Mtpa processing plant by leveraging infrastructure and extensive mineral resources at Black Swan.
Managing Director and CEO Peter Harold emphasized the revised MRE as a critical advancement for de-risking the project restart. Recent underground drilling from the Gosling drill drive enhanced the understanding of grade distribution within serpentinite and talc-carbonate ores below the existing open pit. This insight is vital for optimizing metallurgical outcomes and refining pit designs, which will inform upcoming Ore Reserve updates and the Bankable Feasibility Study (BFS).
Resource Overview:
• The 2022 MRE, prepared by Golder Associates, totals 28.9Mt grading 0.63% nickel, containing 181kt of nickel metal (up from 170.9kt in the 2014 estimate).
• Reported above a 0.4% Ni cut-off, the resource adheres to JORC 2012 guidelines.
• Poseidon’s geology team validated drill data and mineralization domains, while Golder oversaw estimation and classification
New Drilling Data:
• Incorporated 5,144m of diamond drilling (24 holes, 2021–2022) and 2,481m of RC drilling (14 holes, 2019).
• Focused on infill drilling 125m below the open pit to delineate serpentinite and talc-carbonate-hosted resources, improving confidence in Measured and Indicated categories
Geological Context
The Black Swan Komatiite Complex (BSKC) comprises a 3.5km-long sequence of olivine cumulate and spinifex-textured komatiite flows, enclosed by intermediate-facies volcanic rocks. Post-emplacement alteration (serpentinization, talc-carbonate) modified primary textures but preserved nickel sulphide mineralization.
Mineralization Characteristics:
• Host Lithologies: Serpentinite (antigorite-dominated core) surrounded by talc-magnesite and dolomite-altered komatiites.
• Sulphide Types:
• Fine-grained interstitial composites (2–10% of host rock): Pyrite-millerite-magnetite±violarite in serpentinite; vaesite-polydymite in talc-carbonate zones.
• Coarse-grained blebby composites: Localized to the “main lens” (11,200N–11,450N grid), contributing to higher grades (S/Ni >1).
Structural Zones:
• Main Lens: Up to 50m thick, hosting most coarse-grained sulphides.
• Hanging Wall Lenses: Thinner, millerite-dominated with S/Ni <1.
• Footwall Lenses: Fine-grained sulphides in less altered komatiites
Strategic Implications:
The updated MRE supports ongoing pit design optimization and underground mining studies at Silver Swan and Golden Swan. These efforts aim to consolidate Ore Reserves for the BFS, aligning with Poseidon’s goal of restarting Black Swan as a nickel sulphide concentrate producer
(Source: Press Releases – www.wcsecure.weblink.com.au/pdf/POS/02538190.pdf)
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