Altair Minerals Reports 10m at 10.15g/t Au From South Oko Trenching

Altair Minerals Reports 10m at 10.15g/t Gold From Maiden South Oko Trenching

Altair Minerals (ASX: ALR) has reported maiden trenching results from its South Oko prospect ("SOKO") in Guyana, headlined by the Altair Minerals South Oko gold trench results 10m at 10.15g/t Au from Trench 06. According to the company, this result ranks as the fourth highest "grade times interval width" trench intercept reported to date along the Oko Shear Contact, a structurally significant corridor that Altair controls for approximately 14 kilometres at SOKO.

All six deep trenches completed at the W1 anomaly returned gold mineralisation, pointing to a broad, structurally controlled system extending across an approximate 1.0 kilometre north-south by 1.2 kilometre east-west footprint. According to the announcement, the system remains open in every direction.

"With 15,000m of RC drilling at South Oko imminent, we are now moving from systematic surface targeting into the first substantial drill test of a significant target, whereby trenching, geochemistry and geophysics collectively align and indicate is a significant emerging gold system." — CEO Faheem Ahmed

Every Deep Trench Hits Gold as the W1 Anomaly Opens Up

The maiden trenching program at SOKO comprised nine trenches in total, six deep (greater than 3 metres depth) and three shallow (less than 3 metres depth), with a combined sampled length of 2,478 metres. The six deep trenches penetrated below the intensely leached upper lateritic profile into better-preserved saprolite, a chemically weathered rock that retains its original texture but has been altered in place.

According to the company, four anchor intercepts define the spatial footprint of the W1 mineralised system: Trench 04 marking the northwestern extent, Trench 08 situated approximately 1.0 kilometre southeast, Trench 09 positioned 1.2 kilometres east and appearing to represent a separate north-south trending quartz-vein system, and Trench 06 located 370 metres south of Trench 04, positioned lower in the weathering profile where mineralisation is reported to be better preserved.

Ranking Fourth on the Oko Shear Contact

Altair states that when trench results are ranked by grade multiplied by interval width, a standard exploration metric used to compare intercepts, its Trench 06 result places fourth along the entire Oko Shear Contact against results reported by companies operating on this structure.

The company noted this ranking is notable given that Altair has tested only approximately 1.5 kilometres of its 14-kilometre landholding along the Oko Shear Contact at SOKO. Furthermore, the results were achieved early in the exploration campaign, and the most prospective structural zones to the west and southwest remain untested due to duricrust cover.

Duricrust: Exploration Challenge and Untested Opportunity

What Is Duricrust?

Duricrust is a hardened, iron-rich surface layer formed through prolonged tropical weathering. In Guyana's deeply weathered terrain, it forms a dense, lateritic cap over underlying rock, limiting the effectiveness of surface exploration tools. Geologists commonly describe this as a leached cap.

Why Does This Matter for the SOKO Story?

According to the announcement, the two strongest trench results, TR-W1-04 and TR-W1-06, both intersected mineralisation on their western ends before being terminated by hard duricrust. Trench 04 was extended only 32 metres west before hitting duricrust, while Trench 06 was extended just 6 metres west before encountering laterites and gravels.

Ground induced polarisation (IP) chargeability surveys, a geophysical technique that detects sulphide minerals often associated with gold mineralisation, together with structural interpretation, indicate the shear corridor continues west and southwest beneath this cover. The company states this untested ground is the primary target of the imminent 15,000-metre RC drilling program.

Key Terms Explained

• Saprolite: Weathered rock that has retained its original structure but undergone chemical alteration, often preserving mineralisation better than material closer to surface.
• IP Chargeability: A geophysical method used to detect sulphide minerals in the subsurface, frequently associated with gold systems.
• Shear Zone: A zone of structural deformation where rock movement has occurred, commonly acting as a pathway for gold-bearing fluids.
• Grade x Interval Width: A metric combining the thickness and richness of a mineralised intercept, used to compare results across trenches or drill holes.

A Staged Exploration Approach From Soil to Drill

According to the announcement, Altair's exploration at SOKO has followed a staged sequence. Soil sampling first defined the W1 anomaly, described as the largest coherent gold-in-soil anomaly (above 100 parts per billion) identified along the Oko Shear Contact to date. Auger sampling at 2.5 metres depth then supported the interpretation that the anomaly reflected a proximal gold source rather than material transported from elsewhere.

Geophysical surveys subsequently confirmed structural continuity of the shear contact beneath the surface, while grab samples collected from the base of initial trenches returned up to 35 grams per tonne gold, providing early confirmation of high-grade, in-situ mineralisation. Pole-dipole IP surveys then identified deeper chargeability structures suitable for drill targeting, culminating in the maiden trenching results now reported.

The next step outlined by the company is an imminent 15,000-metre Phase I reverse circulation (RC) drilling program, designed to test beneath the duricrust cover along the western and southwestern extension of the shear corridor.

Weathering Profile Suggests Results May Understate Potential

A key technical observation relates to the influence of Guyana's weathering profile on gold grade distribution. Intense tropical weathering at SOKO extends from surface to depths of approximately 40 metres, with strong leaching noted in the upper 4 to 15 metre zone.

The company notes that Trench 06 sits approximately 30 metres lower in elevation than Trench 04 along the same structural trend, and returned grades approximately eight times higher. Altair states this is consistent with improved preservation of mineralisation lower in the weathering profile, adding that the deep trenches remain within the upper portions of a regolith system extending to roughly 40 metres depth. RC drilling is consequently expected to provide the first substantive test of the system at greater depth.

SOKO in the Context of the Wider Oko District

The Oko Shear Contact running through SOKO is described by Altair as the same structural corridor hosting more than 9 million ounces of gold across four deposits located approximately 3.5 to 4 kilometres to the north. In addition, Altair holds approximately 428 square kilometres of contiguous landholding across the Greater Oko project area.

Current trenching covers only the first 1.5 kilometres of the approximately 14 kilometres of Oko Shear Contact held by Altair at SOKO, while surface geochemistry to date has covered only around 3.5 kilometres of that strike length.

The broader Guiana Shield region has attracted notable corporate transaction activity in recent years:

Altair holds the right to earn up to 70% of the Greater Oko Project, subject to conditions precedent, as disclosed under the JORC Code reporting requirements accompanying the announcement.

Planned Next Steps

With trenching having confirmed a widespread mineralised system and identified the western duricrust corridor as an untested target, Altair has outlined the following workstreams:

According to the company, the RC program's primary objective is to test the full extent of the western and southwestern shear corridor beneath the duricrust cap, an area where the strongest trench results to date appear to have been interrupted by cover rather than by the conclusion of mineralisation.

Investor Considerations

The Altair Minerals South Oko gold trench results 10m at 10.15g/t Au announcement includes several features commonly assessed by investors in early-stage gold exploration:

• All six deep trenches returned gold mineralisation across a widespread area
• A trench result ranking fourth along the Oko Shear Contact, based on the company's own comparative analysis
• An untested western corridor beneath duricrust cover where the strongest trenches were terminated by cover rather than a decline in grade
• Trench results reported to align with IP chargeability, soil geochemistry, auger data and structural interpretation
• Only 1.5 kilometres of a 14-kilometre shear contact trenched to date, with 3.5 kilometres geochemically sampled
• An imminent 15,000-metre RC drilling program flagged as the first substantive drill test of the system

Key Takeaway: Altair Minerals has reported maiden trench results at South Oko confirming a widespread, structurally controlled gold system, including an intercept ranked fourth-best reported along the Oko Shear Contact, across a footprint the company describes as open in all directions. With a 15,000-metre RC drilling program said to be imminent and the most prospective structural corridor still untested beneath duricrust cover, further exploration outcomes are anticipated in coming months.

Ready to Learn More About Altair Minerals and the South Oko Gold Project?

With maiden trenching returning results ranked fourth-best along the entire Oko Shear Contact, an imminent 15,000-metre RC drilling programme, and only 1.5 kilometres of a 14-kilometre structural corridor tested to date, Altair Minerals (ASX: ALR) is entering a potentially transformative period for the project. Investors looking to understand the full scope of the Greater Oko Project, Altair's earn-in terms, and the company's broader exploration strategy can find further details directly at altairminerals.com.au.