Terrain Minerals (ASX: TMX) Approves 10,905-Metre Lightning Drill Campaign

Terrain Minerals has approved its largest reverse-circulation drilling campaign to date, committing to 86 holes across the Lightning gold-silver deposit and nearby exploration targets at its wholly owned Smokebush Project in Western Australia.

The 10,905-metre program is expected to begin in the second half of October 2026, with drilling contractors appointed. More than half of the planned metres will be directed at expanding and increasing confidence in the existing Lightning Mineral Resource, while the remainder will test extensions and targets that could represent additional mineralised structures.

The campaign follows Terrain’s maiden Inferred Mineral Resource for Lightning, announced in July. That estimate comprises 677,000 tonnes at 2.5 grams per tonne gold for 54,000 ounces of gold, along with 156,500 ounces of silver.

Within that inventory, 157,000 tonnes at 3.5 grams per tonne gold for 17,500 ounces are contained in an optimised open-pit shell. The balance was reported under underground mining assumptions, making potential growth in the shallower open-pit component a central objective of the new drilling.

Infill drilling targets resource upgrade

Terrain will allocate 54 holes and 5,735 metres to resource drilling across the Lightning and Monza structures. The program is designed to tighten drill spacing, potentially support the conversion of parts of the resource from the Inferred to Indicated category, and test whether near-surface mineralisation outside the current shell could be incorporated into a larger pit.

An upgrade to Indicated status would allow Terrain to undertake initial mining studies. Executive director Justin Virgin said this aligned with the company’s strategy of assessing a potential small-scale toll-milling operation to fund broader exploration and development.

Lightning’s mineralisation begins at surface and remains open along strike and at depth, according to Terrain. The northern end of the main deposit is also under-drilled. Eight exploration holes covering 960 metres will test that northern strike extension, with successful results potentially contributing to the next resource update.

Testing for additional Lightning-style systems

The remaining 32 holes, totalling 5,170 metres, will assess exploration targets across the granted mining lease. Terrain’s geological interpretation is that Lightning may be one of several sub-parallel, shear-hosted gold systems within the same greenstone package, rather than an isolated structure.

Sixteen holes will test induced-polarisation chargeability anomalies, 14 will investigate interpreted extensions at Lightning North and Target 13, and two will test a central surface soil anomaly. The targets were generated using induced-polarisation surveys, soil geochemistry, existing drilling and geological interpretation.

Among them is North Monza, described by Terrain as the strongest chargeability anomaly recorded in its 2026 survey. Five holes are also planned at Target 1-IP, a previously undrilled north-south structure about 1.5 to 1.9 kilometres west of Lightning.

These geophysical corridors remain interpretations rather than confirmed geological structures. The campaign therefore combines a resource-development program around an established deposit with higher-risk drilling aimed at establishing whether Smokebush contains additional mineralised systems.