Great Southern Mining Gold Discovery Extends Strike to 3.5km

Great Southern Mining Strikes Gold With 3.5km Extension at Golden Boulder Discovery

Great Southern Mining (ASX:GSN) has delivered impressive exploration results from its Golden Boulder discovery, part of the company's 100% owned Duketon Gold Project in Western Australia. Final assays from the late-2025 reverse circulation drilling programme have now extended the Great Southern Mining gold discovery to approximately 3.5km of strike along the interpreted Rosemont Shear Zone.

The latest results demonstrate significant gold intercepts across multiple drill lines, with standout intersections including 5m at 3.5 g/t Au from 39m in hole 25GBRC064 and 8m at 1.1 g/t Au from 45m in hole 25GBRC063. Importantly, most drilling remains shallow at less than 100m below surface, suggesting substantial potential for deeper mineralisation.

Managing Director Commentary

"We are extremely pleased with the results from our latest RC drilling programme at Golden Boulder. We have successfully achieved all desired outcomes, including significant strike extensions to known mineralisation, improving continuity of mineralisation in the north of the prospect and defining new mineralisation in previously undrilled areas in the south." – Matthew Keane, Managing Director

Strategic Location Between Major Gold Deposits

Golden Boulder's position is particularly compelling from an investment perspective. The discovery sits strategically between Regis Resources' (ASX:RRL) multi-million-ounce Duketon Project and Genesis Minerals' (ASX:GMD) recently acquired Laverton tenure. This placement positions GSN's asset in one of Western Australia's most prolific gold corridors.

Furthermore, the Golden Boulder area features over 50 historical workings spanning a ~3.7km strike, with historical production records from 1900-1955 showing 1,915 tonnes at 28.6 g/t Au for 1,761 ounces of gold. This historical context validates the area's gold endowment and suggests the potential for substantial mineralisation at depth.

Three Core Objectives Achieved in Latest Drilling

The recent 56-hole RC drilling programme totaling 5,234m successfully met all three strategic objectives:

1. Infill and Extensional Drilling in the North

The programme significantly improved continuity and understanding of mineralisation controls, with exceptional intercepts including:

• 2m at 2.2 g/t Au from 39m and 6m at 6.7 g/t Au from 48m, including 1m at 34.5 g/t
• 5m at 5.1 g/t Au from 25m, including 1m at 23.9 g/t Au
• 9m at 1.8 g/t Au from 19m, including 2m at 5.0 g/t Au

2. Southern Extensions Along 1.7km of Prospective Trend

Every drill line crossing the prospective shear zone recorded significant gold intercepts, with highlights including:

• 3m at 3.5 g/t from 72m in hole 25GBRC057
• 4m at 1.7 g/t Au from 30m, including 1m at 5.4 g/t Au
• 6m at 1.6 g/t Au from 185m, including 1m at 6.7 g/t Au

3. First-Pass Drilling of Southernmost 1.3km

Significant gold mineralisation was recorded in previously underexplored areas where historical drilling averaged only 10-20m depth, including:

• 2m at 5.0 g/t Au from 86m in hole 25GBRC087
• 5m at 0.9 g/t Au from 133m, including 1m at 2.5 g/t Au
• 4m at 1.4 g/t Au from 24m in hole 25GBRC085

Understanding the Rosemont Shear Zone

What is a shear zone and why does it matter for gold exploration?

A shear zone is a geological structure where rocks have been deformed by intense pressure and movement along fault systems. In addition, gold exploration considers shear zones particularly valuable because they create ideal conditions for gold mineralisation:

• Fluid pathways: Shear zones act as conduits for gold-bearing fluids
• Structural traps: The deformation creates spaces where gold can precipitate and accumulate
• Regional significance: Major shear zones often control the location of large gold deposits

The Rosemont Shear Zone at Golden Boulder is the same structural system that hosts Regis Resources' major gold deposits, making it a high-priority exploration target with proven potential for significant mineralisation.

Upcoming Catalysts Drive 2026 Value Creation

GSN has outlined an aggressive exploration timeline that positions 2026 as a pivotal year for value creation:

Immediate Term (February-March 2026)

• Deep diamond drilling programme commencing to test mineralisation at depth
• Co-funded by the Western Australian Government Exploration Incentive Scheme (EIS)
• Structural data collection to refine geological models

Q2 2026

• RC drilling recommencing in April at both Golden Boulder and Amy Clarke prospects
• Focus on extending higher-grade mineralisation zones
• Testing depth extensions beyond current shallow drilling (predominantly <100m at Golden Boulder, <50m at Amy Clarke)

The company's systematic approach to exploration, combined with government co-funding support, demonstrates both technical rigour and capital efficiency in advancing the project.

Investment Thesis: Multiple Value Drivers Converging

Golden Boulder presents a compelling investment opportunity built on several key pillars. However, the Great Southern Mining gold discovery requires careful evaluation of multiple factors:

The combination of extensive strike length, shallow drilling depth, and high-grade intersections suggests Golden Boulder could develop into a substantial gold resource. With most historical drilling averaging only 10-20m in the southern areas, the potential for discovering significant mineralisation at depth remains largely untested.

Consequently, GSN's 100% ownership of the ~550km² tenement holding provides significant exploration upside beyond Golden Boulder, with the Amy Clarke prospect also showing promising results in recent programmes.

Why Investors Should Follow Great Southern Mining

GSN has positioned itself as a compelling gold exploration story in one of Australia's premier mining jurisdictions. Furthermore, the company's systematic approach to exploration, strategic asset positioning, and upcoming drilling catalysts make it a stock worth monitoring closely.

Key reasons to track GSN:

• Proven exploration success with consistent high-grade gold discoveries across multiple prospects
• Strategic location in the heart of Western Australia's Duketon Gold Province
• Significant scale potential with 3.5km of strike identified and drilling remaining shallow
• Government support through EIS co-funding validates project quality
• Multiple upcoming catalysts with diamond drilling commencing and RC programmes planned for Q2 2026
• 100% ownership of substantial tenement package providing exploration optionality

Key Takeaway:

Great Southern Mining has demonstrated the ability to consistently deliver high-grade gold discoveries at Golden Boulder, with the latest results extending mineralisation to 3.5km of strike. With drilling predominantly less than 100m below surface and upcoming deep diamond drilling programmes, GSN offers significant leverage to gold discovery success in a premier mining district. The combination of proven geology, strategic location, and systematic exploration approach positions 2026 as a potentially transformational year for the company.

The upcoming deep drilling programme represents a critical inflection point that could provide substantial value if significant mineralisation is discovered at depth along the 3.5km strike length. For instance, investors seeking exposure to gold exploration success in a tier-one mining jurisdiction should consider that GSN warrants close attention as drilling programmes advance through 2026.

Could Great Southern Mining Be Your Next Gold Investment?

GSN's impressive 3.5km gold discovery at Golden Boulder, combined with upcoming deep diamond drilling programmes and strategic positioning within Western Australia's premier gold corridor, presents a compelling exploration story. With government co-funding support and multiple catalysts planned for 2026, now is the time to evaluate whether Great Southern Mining deserves a place in your portfolio. Discover more about GSN's projects and investment potential.