⚒️ Southern Hemisphere Mining Limited is pleased to share an update on the Company’s Llahuin Southern Porphyry deep Copper-Gold target by JV partner FMR Resources.
- Reprocessed aeromagnetic (MAG), magnetotelluric (MT) and induced polarisation (IP) data define a coherent geophysical target consistent with a large copper porphyry system
- Geophysical results align with surface mapping and re-logging of historic drillholes that confirmed alteration typical of the upper levels of a copper porphyry system
- High amplitude MT target indicates a large, strong, conductive source at depth
- Shallow historic drilling confirms porphyry mineralisation above the target
- Phase I drill target finalisation underway with drilling to commence early Q4 2025
FMR Resources Limited is pleased to advise that reprocessing of multiple geophysical datasets has refined a large, deep-seated drill target at the Southern Porphyry prospect within the Llahuin Project JV with Southern Hemisphere Mining Limited (ASX:SUH), Chile (see Figure 1).
The reprocessed aeromagnetic, magnetotelluric, and induced polarisation surveys now define a coherent pattern of anomalies typical of a copper porphyry system. The magnetic body lies to the south of the main target area, while the MT resistivity anomaly lies to the north and partially overlaps the IP low resistivity anomalies. Strong IP chargeability anomalies flank the magnetic body on the eastern and western sides. This spatial relationship is characteristic of mineralised porphyry systems, where magnetite-bearing intrusives are flanked by altered, sulphide-bearing phases.
FMR Managing Director, Mr Oliver Kiddie said:
“The reprocessed geophysics gives us a much sharper and more confident set of targets at Southern Porphyry.
The alignment between the magnetics, MT, and IP datasets, combined with the alteration and geochemical signatures we have mapped at surface and in historic drillholes, is compelling, and exactly what we want to see to guide Phase I drill targeting.
This is a genuine high-priority porphyry target which we are on track to test in early Q4 2025.”
Geological Setting
The Southern Porphyry target lies within a 6 km-long mineralised corridor at Llahuin that hosts multiple copper–gold–molybdenum porphyry centres (see Figures 2 and 6). Field mapping completed in June and July 2025 identified argillic alteration, silicification and epithermal quartz veining at the surface, along with zones of secondary copper mineralisation assemblages typical of the upper levels of a copper porphyry system.*
Re-logging of historic drillholes confirmed these features at depth, with intervals showing hydrothermal alteration, silicification, and disseminated chalcopyrite–pyrite mineralisation. These observations suggest a telescoped system, characterised by epithermal-style veining and alteration preserved above a deeper porphyry core.*
*Refer to FMR ASX announcement “Phase I Drilling Target Areas Refined at Southern Porphyry” dated 9 July 2025
Figure 1. 3D view of Southern Porphyry, looking south-west, showing IP chargeability models (purple) and IP resistivity models (red), Aeromagnetic model central to IP models, and the MT resistivity model at depth
Figure 2. 3D longitudinal view looking north-west of the Llhahuin project, showing the Southern Porphyry target area in relatation to the SUH Deposits within the 6km porphyry corridor.
Geophysical Context
MT data from the Llahuin project was subjected to rigorous QAQC and inverted in 3D using Viridien’s RLM code. The resistivity anomaly previously identified was resolved in all inversions and determined to be robust, with further modelling able to provide greater information about target geometry and helping understand the relationship with the geology.
Integration of the reprocessed datasets depicts:
- Magnetic body – prominent high on the southern side of the target, likely representing magnetite-bearing intrusive phases.
- MT resistivity anomaly – immediately north of the magnetic body, coincident in part with IP resistivity lows, potentially representing altered and mineralised porphyry.
- IP chargeability anomalies – flanking the magnetic body to east and west, consistent with disseminated sulphide halos around the intrusive core.
This configuration is consistent with globally recognised porphyry models*, in which a central magnetite-rich core is flanked by sulphide-rich zones and broad alteration halos (see Figures 1-5)
* Reference: Sillitoe 2010, Economic Geology, v. 105, pp. 3–41
Figure 3. Map showing the spatial relationships between the geophysical models on TMI-RTP aeromagnetic imagery.
Figure 4. Map showing the spatial relationships between the geophysical models and geological mapping.
Figure 5. Cross section A-A’, looking north-east, showing the spatial arrangement of the geophysical models at Southern Porphyry in relation to the Ferro deposit (SUH) (window +- 250m).
Figure 6. Southern Porphyry target area within the Llahuin Project Joint Venture concessions*
Next Steps:
- Finalise drill contractor engagement in the coming weeks
- Complete final drill program design incorporating the refined geophysical models
- Statutory drilling approvals and site preparation
- Commence Phase I drilling at Southern Porphyry early Q4 2025
The Full PDF is available below.
News Release
Date: 13 August 2025 | ASX Code: SUH | Frankfurt Exchange: NK4
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Southern Hemisphere Mining Limited is an experienced minerals explorer in Chile, South America.
Chile is the world’s leading copper producing country and one of the most prospective regions of the world for major new copper discoveries. The Company’s projects include the flagship Llahuin Porphyry Copper-Gold-Moly Project and the Los Pumas Manganese EV Battery Project, both of which were discovered by the Company.
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