Broken Hill Mines Unveils Major High-Grade Silver-Lead-Zinc Discovery Beneath Globe-Vauxhall Shear at Rasp Mine

Innovative Drilling Technique Overcomes Historic Technical Barriers

Broken Hill Mines has reached a pivotal technical breakthrough by successfully drilling through the Globe-Vauxhall Shear, a structural barrier that historically hindered precise drilling into the Centenary Zone. Prior to BHM's current program, no company had managed to drill through the Shear without significant drill bit trajectory distortion, resulting in inaccurate holes and many abandoned attempts. Only 24 holes had been drilled into the Centenary Zone before, mostly from surface drilling in the 1980s.

The company employed an innovative method involving drilling a large diameter hole through the Shear, which was then cased, enabling smaller 'daughter' holes to be drilled accurately into the Centenary Zone without disruption. This advancement has unlocked access to mineralisation that remained largely unexplored for decades since the orebody's discovery in 1983. This successful drilling technique marks a significant technical achievement, opening new exploration opportunities at the Rasp Mine.

Outstanding Grade and Thickness Surpass Existing Resource Estimates

The initial drill hole, WMDD6391, delivered results markedly superior in both grade and thickness compared to previous interpretations of the Centenary Zone orebody. It intersected 25.8 metres at 11.7% zinc equivalent and 323 grams per tonne silver equivalent from 415.1 metres depth. Within this intercept, a higher-grade section of 10.9 metres graded 17.3% zinc equivalent and 479 grams per tonne silver equivalent from 422 metres, containing 58 g/t silver, 4.1% lead, and 11.5% zinc.

The intercept’s width is roughly 500% greater and the grade about 27% higher than the 2024 Inferred Mineral Resource Estimate of 4.8 million tonnes at 9.2% zinc equivalent and 255 g/t silver equivalent. This substantial outperformance indicates significant expansion potential for the Centenary mineralised zone. Initial mineralogical studies suggest a closer affinity to Broken Hill's historic Main Lode orebody rather than the Western Mineralisation, implying a potential step-change in scale.

Centenary Zone Remains Largely Untapped Despite Four Decades Since Discovery

Discovered in 1983, approximately 100 years after Rasp's Main Lode, the Centenary orebody lies structurally beneath the Globe-Vauxhall Shear. It is one of the least drilled segments of the Rasp system, with only 24 holes mostly from surface drilling and minimal follow-up in the last 25 years. This low drill density contrasts with the orebody’s scale, currently hosting an Inferred Mineral Resource Estimate of 4.8 million tonnes at 9.2% zinc equivalent and 255 g/t silver equivalent.

The Centenary Zone extends about 1,600 metres along strike and plunges vertically over 280 metres, remaining open at depth and along strike in multiple directions. Its strategic location, approximately 200 to 300 metres from current Western Mineralisation operations, places it within reach of existing declines, ventilation, and haulage infrastructure, offering a brownfields development opportunity with lower capital intensity than a standalone project.

Mineralogical Findings Link Deposit to Historic Main Lode Rather Than Adjacent Orebody

Preliminary mineralogical analysis of drill core from WMDD6391 reveals significant geological differences between Centenary and adjacent Western Mineralisation. The presence of Hedenbergite and Tetrahedrite suggests Centenary closely resembles the Main Lode mineralisation. This distinction indicates Centenary may be part of a different, potentially larger mineralised system than previously recognized.

Further analysis of historic drill pulps and new drilling is planned to confirm these findings. This reinterpretation could substantially affect understanding of Centenary’s size, continuity, and development potential. If Centenary is akin to the Main Lode, it may indicate greater scale and more predictable mining characteristics based on historical Main Lode performance.

Rasp Mine Operations Offer Complementary High-Grade Feed Source

Centenary Zone development offers potential as a high-grade, bulk tonnage feed source for plant expansion in the medium term, complementing BHM’s current 750,000 tonnes per annum operations. Its proximity to Western Mineralisation provides operational advantages by enabling access via existing infrastructure, reducing the need for significant new capital expenditure.

BHM regards Centenary as integral to its medium-term mining strategy at Rasp. Expanding feed sources with this new mineralisation could support ongoing operations and improve ore processing economics through access to higher-grade material. Centenary’s strategic location relative to existing operations presents a material advantage for the company’s development plans.

Accelerated Drilling and Reinterpretation Program Ahead of Q4 2026 Resource Update

Broken Hill Mines is fast-tracking reinterpretation of historic drilling and conducting accelerated drilling to define a new exploration target before updating the Mineral Resource Estimate for the Centenary Zone and Rasp Mine overall. The updated Mineral Resource Estimate is targeted for Q4 2026 release.

Additional drilling is ongoing, with further results expected soon. This accelerated program underscores the company’s confidence in the discovery and commitment to advancing exploration and resource definition. The Q4 2026 resource update will be a key milestone, providing investors with a quantified assessment of expanded mineralisation based on new drilling data, guiding development potential and medium-term mining contributions.

Discovery Signals Potential Major Expansion of Rasp Mine Ore Inventory

Broken Hill Mines describes the Centenary discovery as a major new bulk tonnage, high-grade silver-lead-zinc mineralisation breakthrough, marking a significant advancement in understanding Rasp Mine’s ore endowment. The discovery prompts a full reinterpretation of previous ore models within the Centenary Zone, suggesting historical estimates may have substantially underestimated mineralisation scale and quality.

The highlighted intercept is approximately 500% wider and 27% higher grade than modeled in the 2024 Inferred Mineral Resource Estimate. With Centenary currently hosting 4.8 million tonnes of inferred resources, this could materially increase the company’s ore inventory. The close proximity to existing operations enhances development prospects, as ore could be processed through current facilities with minimal additional capital for mining infrastructure.

Rasp Mine Overview and Strategic Significance

Located in the Broken Hill region, the Rasp Mine is wholly owned by Broken Hill Mines and comprises multiple ore bodies including the Main Lode, Western Mineralisation, and Centenary Zone. The mine operates with a nameplate capacity of 750,000 tonnes per annum and is a cornerstone asset with extensive mining infrastructure and a long operational history.

The Broken Hill region is globally renowned for silver-lead-zinc mining, boasting over a century of exploration and production. The Centenary discovery adds to the region’s potential, indicating significant additional ore opportunities within the broader Broken Hill system. Its strategic location near existing infrastructure positions it as a near-term ore source, pending resource definition and economic assessment.

Upcoming Milestones and Investor Watchpoints

Investors should monitor several key developments in the coming months. Additional Centenary Zone drilling results are anticipated shortly, potentially confirming the discovery’s scale and resource potential. The accelerated drilling program aims to establish a new exploration target ahead of the Mineral Resource Estimate update.

The planned Q4 2026 Mineral Resource Estimate update for the Rasp Mine will be a pivotal event, providing a formal assessment of expanded Centenary mineralisation and the total ore inventory. This update will be critical in evaluating the discovery’s scale and implications for medium-term mining operations and development strategy. Investors are advised to follow company announcements for drilling outcomes, exploration target definitions, and technical analyses as they emerge.