Highlights

  • Great Southern Mining Shares rose 8% on 31 March 2026, followed by drilling commencement update.
  • Diamond drilling has begun at the Golden Boulder discovery within Duketon Gold Project.
  • Program targets deep structures linked to shallow high-grade gold mineralisation
  • Fully funded exploration backed by A$4.6 million capital raising

Great Southern Mining Ltd (ASX:GSN) shares rose 8% to AUD 0.027 during the afternoon session on 31 March 2026, extending a 12-month gain of 35%, as investors responded to the commencement of diamond drilling at its Golden Boulder discovery in Western Australia.

Today’s share price move follows confirmation that deep drilling activities are now underway, marking a key step in advancing exploration at one of the company’s key gold targets within the Duketon Gold Project.

Great Southern Mining is an Australian exploration company focused on gold and base metal projects, with key assets located in established mining regions including Laverton in Western Australia and Mt Carlton in Queensland.

Diamond Drilling Begins at Golden Boulder

The company announced that diamond drilling has commenced at the Golden Boulder discovery, part of its 100%-owned Duketon Gold Project.

The initial phase includes a co-funded diamond drill hole supported by the Western Australian Government’s Exploration Incentive Scheme (EIS). This hole is planned to reach depths of up to 700 metres at the Ogilvies target.

Importantly, this represents the first diamond drilling program in the area and the first attempt to test mineralisation beyond 155 metres depth within the primary mineralised zone.

The objective of the drilling is to investigate deeper geological structures believed to be responsible for multiple zones of shallow gold mineralisation identified in earlier exploration.

Targeting Deep-Seated Gold System

The drilling program has been designed to test structurally complex zones where several key faults intersect, including major shear zones that may act as pathways for gold-bearing fluids.

The Golden Boulder area hosts at least three mineralised trends — the Main Line, East Line, and Ogilvies — extending over a strike length exceeding 3.5 kilometres.

Geophysical interpretation suggests these structures may connect to deeper sources, with the potential that previously identified shallow mineralisation represents only the surface expression of a larger gold system at depth.

By targeting these deeper zones, the current drilling program aims to provide critical geological, structural, and stratigraphic data to better understand the scale and controls of mineralisation.

Strong Historical Results Support Exploration Upside

Previous reverse circulation drilling at Golden Boulder has returned multiple high-grade gold intercepts, supporting the prospectivity of the area.

Notable results include intersections such as 5 metres at 14.57 g/t gold, including 1 metre at 70.94 g/t, as well as several other intercepts demonstrating consistent gold mineralisation across the Main Line trend.

These results underpin the rationale for deeper drilling, with the company aiming to determine whether these high-grade zones extend at depth or connect to a larger mineralised system.

A second diamond drill hole is also planned to target the Main Line mineralisation directly, providing further insights into structural controls and continuity.

Broader Exploration Programs Set to Expand

Beyond the current drilling, Great Southern Mining has outlined plans for extensive follow-up exploration across the Duketon Gold Project.

Major reverse circulation drilling campaigns are scheduled to commence between late April and May 2026, with an initial program covering between 10,000 and 15,000 metres.

These programs will focus on both the Golden Boulder and Amy Clarke discoveries, with drilling designed to extend and infill known mineralisation zones.

At Amy Clarke, earlier aircore drilling identified gold mineralisation across a strike length of approximately 4.7 kilometres, further highlighting the broader exploration potential within the project area.

Additional Exploration Progress at East Laverton

Separately, the company confirmed completion of a deep diamond drill hole at the Diorite Hill target within its East Laverton Project.

The 804-metre hole targeted geological formations considered prospective for platinum group elements, nickel, and copper mineralisation.

Core logging and sampling activities are currently underway, with observations indicating complex sequences of mafic and ultramafic rocks. Select samples are being prepared for geochemical analysis to further assess mineral potential.

Fully Funded for Ongoing Exploration

Great Southern Mining highlighted that it is fully funded to undertake its upcoming exploration programs, following the completion of a A$4.6 million equity capital raising in March 2026.

This funding provides financial flexibility to advance multiple drilling campaigns across its portfolio, supporting continued exploration momentum throughout 2026.

What This Means for Investors?

The share price increase reflects investor response to the transition into a more advanced phase of exploration at Golden Boulder.

The commencement of diamond drilling, particularly targeting deeper structures, represents a significant step in evaluating the broader scale potential of the discovery.

With strong historical drilling results, multiple mineralised trends, and extensive follow-up programs planned, investors are likely to monitor upcoming drilling outcomes and geological insights as key catalysts.