Key Highlights

•  After four holes at Ferro South, drilling has moved towards a deeper target at the Llahuin copper-gold-molybdenum project in Chile.

•  The company is searching for a feeder zone that may have supplied copper to near-surface mineralisation, using copper isotope analysis and other specialised techniques.

•  The first batch of assays from deeper drilling is expected in late November 2026, and the annual general meeting is on 30 November.

Southern Hemisphere Mining (ASX:SUH) has moved its drilling at the Llahuin Copper-Gold-Molybdenum Project in Chile towards a deeper target, after completing four holes at the Ferro South zone. Chair Mark Stowell outlined the strategy in an interview, describing a search for the feeder zone that may have supplied copper to the near-surface mineralisation.

What the company is chasing

In porphyry copper systems, large volumes of lower-grade mineralisation near surface can be connected to a deeper source where fluids were most concentrated. Southern Hemisphere believes this source could contain higher grades than those defined so far. The company is using copper isotope analysis and other specialist targeting techniques to help vector drilling towards it.

Copper isotope ratios can change systematically with distance from a mineralising source, so variations in the data can, in principle, indicate the direction of a feeder. These methods help to prioritise targets but do not confirm mineralisation; only drilling and assays can do that. The approach is increasingly used in porphyry exploration because deep targets are expensive to test, and better vectoring can reduce the number of holes needed.

Recent drilling at Ferro South

Diamond drilling began in late September 2026 to test the newly identified Ferro South zone and deeper copper targets. On 22 October, the company reported that chalcocite, a copper sulphide mineral, had been logged in ongoing drilling at Ferro South. Visual logging of minerals is not a substitute for laboratory assays and does not indicate grade.

This followed copper intercepts announced on 4 August and 1 September 2026. Earlier drilling across the Ferro Central, Ferro South and Cerro areas included 241 metres at 0.42% copper equivalent from 18 metres in hole 24LHRD067, and 180 metres at 0.39% copper equivalent from surface in 24LHRD056. The company website does not state whether these are downhole lengths or which holes fall within Ferro South, and true widths may not be known. Copper equivalent figures combine several metals using price and recovery assumptions that should be checked in the original announcements.

Resource base

Llahuin, which the company says it owns 100%, hosts a mineral resource of 218 million tonnes at 0.38% copper equivalent across three deposits, estimated in July 2025. The company has also cited an exploration target of about 260 to 340 million tonnes. An exploration target is conceptual in nature; there has been insufficient exploration to estimate a mineral resource for that material, and it is uncertain whether further work will do so.

Llahuin lies north of Santiago. Southern Hemisphere also holds the Los Pumas Manganese Project, about 175 kilometres inland from the port of Arica, with a resource of 30.2 million tonnes at 6.24% manganese, and is inviting joint venture interest in that asset.

Why it matters

Large, lower-grade copper resources can be difficult to develop economically. Discovering a higher-grade core or feeder could improve the potential economics of Llahuin, which is why the company is directing effort towards deeper targets. Chile remains the world's largest copper producer, with established infrastructure, mining services and a long history of developing porphyry deposits of this style.

Next steps and risks

The first batch of assays from the deeper drilling is expected in late November 2026. The company's annual general meeting is scheduled for 30 November, which may provide a further opportunity for management to update shareholders on the programme and its funding.

The principal risk at this early stage of the programme is geological: a feeder may not exist where it is modelled, or may not carry economic grades even if intersected. Exploration results can take time, and further capital may be required to continue drilling. Investors should treat the deeper target as a hypothesis until assay results are reported.