⚒️ Southern Hemisphere Mining Limited reports an update from drilling progress on the main Southern Porphyry Target at the Company’s Llahuin Copper-Gold Project in Chile – including Copper-bearing veining and strong potassic–biotite alteration observed above the main target zone.
HIGHLIGHTS
- Drilling at Target A has advanced to 1,198.9m downhole
- Copper-bearing veining and strong potassic–biotite alteration observed above the main MT target zone
- Geophysical data confirms drillhole is above MT target zone
- Drilling temporarily paused due to mechanical failure, replacement gear mobilised to site
- Ground conditions in drillhole remain excellent
- Drilling to recommence imminently, continuing to the planned 1,600 m depth
Below is a full update by JV partner FMR Resources Limited.
“What we are seeing in the core continues to validate our geological and geophysical models. The copper veining, biotite alteration, and potassic overprint are exactly the features we expect above a porphyry centre. Importantly, ground conditions remain excellent.
In addition, the hand held conductivity measurements confirm we are still above the main MT target which, following the current short pause for mechanical reasons, will be tested when we recommence drilling imminently.”
Photo 1. Anhydrite vein with chalcopyrite within alterered prophyry from 1162.3m downhole* (refer to Appendix 1).
*Cautionary Statement: Visual estimates of mineral abundance should never be considered a proxy or substitute for laboratory analyses where concentrations or grades are the factor of principal economic interest. Visual estimates also potentially provide no information regarding impurities or deleterious physical properties relevant to valuations.
Drilling Update
Diamond drillhole 25LHDD0070 has now reached 1,198.9 m downhole, remaining within the upper alteration halo above the large high-amplitude MT anomaly that defines the main porphyry target. Drilling has been temporarily paused due to mechanical failures during recent shifts. Importantly, ground conditions remain excellent. Routine maintenance is underway and replacement gear has been mobilised to site, with drilling expected to resume imminently.
Despite the temporary pause, geological observations remain highly encouraging. Core logging has confirmed visible copper mineralisation in quartz–sulphide veins (see Appendix 1)accompanied by biotite and potassic alteration, typical of the transition into the porphyry environment. These features are consistent with the zonation predicted by the Company’s geophysical and geochemical models. The strong correlation between downhole geology and 3D IP/MAG/MT models continues to reinforce confidence in the targeting model at Southern Porphyry.
Whole-rock geochemical analyses are being conducted on anhydrite–pyrite veins encountered between ~485m and ~1160 m downhole, to determine their chemical progeny and clarify their temporal relationship to the main porphyry mineralising event. In addition, thin-section samples are being collected from key lithological and alteration assemblages to assist with petrographic and mineralogical characterisation of the system.
Key Indicators
Whole-rock geochemical analysis of the anhydrite–pyrite vein assemblages will help determine whether these veins are hydrothermal in origin, and therefore directly related to a porphyry mineralising system, or sedimentary/diagenetic in character and unrelated to magmatic activity. By comparing their major and trace element compositions — particularly ratios of Ca/S, Sr, Ba, Fe, and rare earth element signatures — the analysis will distinguish between magmatic– hydrothermal anhydrite, typically sourced from sulphate-saturated porphyry fluids, and sedimentary anhydrite precipitated from evaporitic brines. Confirmation of a hydrothermal (porphyry-derived) origin would indicate that the current drill intercepts lie within the proximal alteration halo of the mineralising intrusion, providing a key vector toward the porphyry core.
Photo 2. Example of an anhydrite vein with quartz and pyrite from 826.8m downhole*.
In parallel, thin-section petrographic analysis is being carried out on key lithologies and alteration assemblages to characterise mineral textures, paragenesis, and cross-cutting relationships. This work will reinforce the geological framework and geometry of the broader porphyry footprint, improving the understanding of alteration zoning and mineralisation pathways within the Southern Porphyry system.
Photo 3. Potassic alteration in 25LLDD0070 from 840m downhole*.
The Company continues to validate its 3D geophysical models against newly collected downhole magnetic susceptibility and conductivity measurements taken directly from the drill core. This integration of downhole and surface data provides real-time calibration of the geophysical response against observed lithology, alteration, and mineralisation. Preliminary results show that the measured downhole responses correlate well with the upper alteration halo and the known magnetic and chargeability domains, but indicate that the main MT conductive source has not yet been intersected by the current hole. This interpretation is consistent with the ongoing depth profile and supports the view that the drillhole remains above the primary porphyry centre targeted by the program.
At around 1,160 m downhole, the drillhole intersected a zone interpreted as a crackle breccia — a clast supported breccia with a matrix/cement of quartz/anhydrite veining. In porphyry systems, this style of brecciation is commonly developed in the outer zones of the intrusive complex and is interpreted as indicating the relative proximity of a porphyry core or stockwork.
Photo 4. Interpreted crackle breccia from 1183m downhole, which starts from approximately 1160m downhole and continues to the current depth of the hole.
Next Steps
- Resume drilling at Target A toward the 1,600 m planned depth once replacement gear has mobilised to site
- Continue geological logging and collection of whole-rock and thin-section samples
- Conduct downhole geophysics (IP, EM conductivity, spectral gamma) following completion of drilling
- Report additional assay and geological results as they become available
Figure 1. Plan view of Southern Porphyry, showing surface projections of geophysical models, mapped epithermal veining at surface, and planned drill targets
The Full PDF is available below.
News Release
Date: 10 November 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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