GBM Resources Initiates 8,000-Metre Drilling Campaign at Yandan Gold Project to Boost Mineral Resources

Yandan Gold Project: A Million-Ounce Gold System with Significant Growth Potential

Situated within mining leases in Queensland's Drummond Basin, the Yandan Gold Project is one of GBM Resources' flagship exploration assets. It combines historical gold production with current mineral resources, forming what the company describes as a million-ounce gold system. Discovered initially by WMC in 1985, the site was later mined by Ross Mining, which produced 365,000 ounces of gold over six years. Straits Resources (now Aeris Resources) further developed the project with extensive drilling at East Hill in 2007. GBM Resources acquired Yandan from Aeris Resources in 2021 and has since undertaken exploration to refine the resource model.

The current mineral resource estimate at Yandan stands at 12.8 million tonnes at 1.1 grams per tonne, equating to 0.44 million ounces of gold, based on GBM’s recent exploration. When combined with historical production, the total gold output approximates 1 million ounces, achieved with relatively limited drilling. This strong production history and resource base highlight the potential of the broader hydrothermal system, which remains largely untested by modern drilling techniques. The East Hill deposit hosts the primary mineral resource, featuring a high-grade core of 1.1 million tonnes at 5.7 grams per tonne for 201,000 ounces of gold.

Stage 1 Drilling Targets: East Hill, Yandan Pit, South Pit, and Magazine Ridge

The Stage 1 drilling program targets four distinct zones within the Yandan hydrothermal system, each with specific exploration goals. At East Hill, the focus is on extending mineralisation along strike and at depth through reverse circulation and diamond drilling. Historical results include a 191-metre intercept at 4.0 grams per tonne gold from 190 metres depth, with a high-grade interval of 43.7 metres at 13.9 grams per tonne from 325 metres. Notably, drill hole YAN010 recorded 2.5 metres at 248 grams per tonne gold, underscoring the system’s high-grade potential at depth.

The Yandan Pit target aims to explore feeder zones and resource extensions beneath the existing open pit. South Pit will undergo the first-ever east-west oriented drilling to better define and potentially expand its 16,000-ounce inferred resource. The company interprets mineralisation here as occurring at the intersection of breccia pipe margins and a north-south fault, with the new drilling designed to test east-west structures that may enhance grade continuity. Magazine Ridge is a fourth target where drilling will investigate a strong induced polarisation chargeability anomaly aligned with silica alteration, indicating potential for high-grade gold. East Hill drill holes are prioritised to support an updated mineral resource estimate targeted for H1 2027.

Advanced Geophysical Analysis Uncovers Extensive Intrusive-Centered Hydrothermal System

Reprocessing of historical geophysical data alongside newly acquired induced polarisation, aeromagnetic, and radiometric surveys has significantly improved the geological understanding of the Yandan deposit. Historical induced polarisation data from 1987 confirmed Yandan as a major chargeable and resistive anomaly, consistent with silica alteration and sulphide minerals linked to gold mineralisation. Recent surveys validate induced polarisation’s effectiveness in mapping known mineralisation at East Hill and Yandan.

The company interprets Yandan as a breccia pipe underlain by an intrusive body at depth, which likely drives mineralisation. This updated geological model presents Yandan as a larger, more continuous mineralising system than previously recognized. Significant geophysical anomalies extending beyond the current resource footprint remain untested, forming key targets for Stage 1 drilling. Anomalies north of East Hill may indicate offsets of high-grade mineralisation along a stacked fault system, offering promising exploration opportunities.

East Hill’s Stacked Normal Fault Structure Supports High-Grade Gold Potential

East Hill has been reinterpreted as a series of stacked normal faults displacing high-grade mineralisation, a model supported by induced polarisation chargeability data that closely aligns with the resource. This structural framework aids in predicting locations of additional high-grade zones. The existing resource at East Hill includes 1.1 million tonnes at 5.7 grams per tonne for 201,000 ounces, with historic drill intersections confirming exceptional grades at depth.

The highest-grade intercept at Yandan was recorded in drill hole YAN010 at East Hill, intersecting 2.5 metres at 248 grams per tonne gold within the northern normal fault zone. This remarkable result highlights the system’s exceptional high-grade potential at depth and validates Stage 1 drilling targets. Untested geophysical anomalies parallel and extend beyond the current resource footprint, particularly to the north, where offsets of high-grade mineralisation may exist. Prioritised East Hill drilling aims to deliver an updated resource estimate in H1 2027, incorporating Stage 1 results to clarify the deposit’s growth potential.

South Pit East-West Drilling to Explore New Structural Directions

South Pit, located just south of the main Yandan Pit and historically mined, holds a mineral resource estimate of 0.9 million tonnes at 0.6 grams per tonne for 16,000 ounces of gold. GBM Resources interprets mineralisation at South Pit as situated at the intersection of breccia pipe margins and a north-south fault, suggesting potential additional mineralisation along subsidiary faults. To date, no drilling has been conducted with an east-west orientation, which may explain limited grade continuity in the current resource.

The Stage 1 program targets east-west oriented structures at South Pit to expand the resource and potentially connect it northward along strike to East Hill and Yandan Pit. This structural linkage could unify the broader hydrothermal system and demonstrate mineralisation continuity across multiple deposits. The first systematic east-west drilling at South Pit marks a strategic shift in exploration and may unlock further resource growth in this underexplored area.

Three-Month Drilling Schedule Using DDH1 850 Multipurpose Rig

The Stage 1 program consists of 4,000 metres of reverse circulation and 4,000 metres of diamond drilling, totaling 8,000 metres. Utilizing a DDH1 850 Multipurpose rig, the drilling is scheduled for completion within approximately three months. This timeline supports systematic progress while focusing on key milestones, especially the updated East Hill resource estimate targeted for H1 2027.

The combined use of reverse circulation and diamond drilling balances rapid exploration coverage with the collection of high-quality core samples essential for detailed geological and assay analysis. Reverse circulation drilling enables broad area coverage, while diamond drilling at priority zones provides detailed geological data for resource definition. Prioritising East Hill drill holes within this timeframe ensures assay results can inform the updated resource estimate.

Historical Production and Resource Expansion Drive Exploration Priorities

Yandan’s gold production history provides a strong base for current exploration. Ross Mining produced 365,000 ounces over six years without strip mining, indicating mineralisation remains adjacent to and beneath historic pits. This suggests the open pit did not fully exhaust mineralisation, leaving extensions and deeper ore shoots within the mining footprint.

GBM Resources’ current mineral resources total 460,000 ounces from recent delineation efforts, demonstrating the success of modern exploration in defining additional gold beyond historical production. Stage 1 drilling aims to discover new resources within the approximately 1,500-metre by 650-metre Yandan system while expanding existing resources at East Hill, Yandan Pit, and South Pit. This dual focus on discovery and resource growth reflects confidence in the hydrothermal system’s prospectivity and remaining mineralisation.

CEO Daniel Hastings Highlights Exploration Strategy and Market Outlook

GBM Resources CEO Daniel Hastings stated that Yandan represents a million-ounce gold system when combining historical production and current resources, with much of the larger hydrothermal system still untested by modern drilling. He described Yandan as one of the company’s most exciting exploration prospects, aiming to grow the resource base and test significant mineralisation opportunities at depth and along strike. Hastings characterised the Stage 1 drilling as the first systematic evaluation of the refined geological model.

He noted that reprocessing historic geophysics alongside new induced polarisation and aeromagnetic data sharpened the company’s understanding, enabling a focused drilling program targeting new gold discoveries. Hastings emphasized the potential for substantial new resources at Yandan Pit, East Hill, South Pit, and Magazine Ridge, with drilling results expected over the coming months. This outlook reflects management’s confidence in the technical merits and prospectivity of the multiple targets.

Upcoming Results and Key Milestone for Investors

GBM Resources plans to release Stage 1 drilling results progressively as assays are received and interpreted, allowing the market to monitor program effectiveness and progress toward resource expansion. Prioritising East Hill drill holes supports delivering an updated mineral resource estimate for East Hill in the first half of 2027, providing a clear near-term catalyst for investors.

The three-month drilling schedule means assay results could begin emerging soon, subject to standard laboratory processing times. The updated resource estimate in H1 2027 will quantify the success of Stage 1 in expanding East Hill’s high-grade resource. Investors will likely focus on initial assay announcements, especially from high-grade normal fault zones at East Hill and the new east-west drilling at South Pit.