Southern Hemisphere, FMR piece together Chilean copper porphyry puzzle

Joint venture partners FMR Resources and Southern Hemisphere Mining have added yet more visual copper to the geological puzzle at their Llahuin copper-gold project in Chile, with the fourth deep diamond drill hole intersecting broad zones of mineralisation.

The latest 1068-metre hole at the company’s “Target L” site has delivered another encouraging set of clues in its hunt for a potentially monster copper porphyry deposit. The hole reportedly cut through multiple mineral-bearing rock units, confirming the presence of copper and molybdenum sulphides over an extensive interval from 144m to 815m downhole.

The drilling at Target L represents the latest calculated move in the search for the Llahuin project’s Southern Porphyry, building on geological and structural information collected from three previous deep holes in recent months.

The partners say the latest results confirm the drill bit is already inside the mineralised footprint of a large-scale porphyry system, with visual logging of the core picking up multiple porphyry-related intrusive phases, including andesitic porphyry, quartz-diorite and dranodiorite porphyry.

These rocks are often linked to stockwork veining and brecciation, characteristic features of mineral-rich hydrothermal fluid environment.

Notably, geologists observed visible copper mineralisation, including chalcopyrite and chalcocite, along with molybdenum sulphides within various vein sets.

The observations suggest the drill bit has intersected the edge of an elongated mineralised porphyry intrusive corridor, first encountered in the previous hole at Target K.

Drilling at Target L has intersected broad zones of variably mineralised stockwork breccia and porphyry. The visible copper and molybdenite sulphide, combined with the alteration and brecciation textures, are interpreted to mark the edge of an elongate mineralised porphyry intrusive corridor, first intersected in Target K.

Mr Kiddie added the next critical round of drilling would happen once a comprehensive suite of assays had been received. Specifically, multi-element geochemistry from the hole will be used to fingerprint alteration signatures and identify where fluids have most likely flowed from within the massive mineralised system.

Earlier holes at Targets A and C appeared to have clipped the outer alteration halos of the system.

The third hole at Target K then punched closer to the action before this latest hole at Target L, collared from the same drill pad as Target C, was plunged to test a promising area to K’s south and east.

The structural information from the latest drilling shows a transition in vein orientations downhole, which the company believes reflects different pulses of intrusion-related fluids or indicates that the drill path has traversed the copper fluid source.

The Southern Porphyry target lies within a six-kilometre-long mineralised corridor at the Llahuin project in one of Chile’s world-class copper-producing regions.

The JV partners formalised their exploration arrangement in mid-2025 after FMR joined the fray, funding $13 million in exploration over five years to earn up to 60 per cent of Southern Hemisphere’s Southern Porphyry ground.

Just north of the JV area, Southern Hemisphere holds three shallower deposits – Central, Ferro and Cerro – containing a combined resource of 218 million tonnes grading 0.38 per cent copper equivalent. The existing resource highlights the prospectivity of the broader project and points to the potential for a much larger, deeper feeder system – the very target the JV is pursuing.

The companies say that phase one of the drilling program has now wrapped up after delivering more than 5000m of core. The partners will now integrate all the geological, geophysical and geochemical datasets to refine a three-dimensional model of the porphyry’s whereabouts before gearing up for a phase two tilt later this year.

With each piece of the puzzle falling into place, all eyes will now turn to the pending assay results, which will be vital for designing the next round of drilling and potentially uncovering a mammoth Andean copper story.

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