⚒️ Southern Hemisphere Mining Limited reports the diamond drill rig has now commenced drilling at Target C at Llahuin’s Southern Porphyry, located approximately 545 m to the west-south-west of the Target A collar – where all planned downhole geophysical surveys on drillhole 25LHDD070 have now been completed.
The combined IP, conductivity, magnetic susceptibility and spectral gamma datasets will be incorporated into the updated 3D geophysical models. Preliminary interpretation of the downhole data, together with the surface MT and IP modelling, supports the existing view that the primary MT conductive source remains untested below Target A drillhole 25LHDD070 and is likely positioned offset from the drillhole.
The Southern Porphyry target is within the Llahuin Project Joint Venture, with FMR Resources, Chile.
- Downhole geophysical probing completed on drillhole 25LHDD070 at Target A.
- Downhole logging implies magnetotelluric (MT) zone is larger than originally modelled.
- Results support the interpretation that the primary MT source remains untested below the drillhole.
- Downhole IP indicates off-hole chargeability anomaly, interpreted to relate to sulphide.
- Drilling commenced at Target C ~545 m west-south-west of Target A.
- Target C is defined by a strong MT response closer to the surface than Target A.
- Target C drillhole 25LHDD071 is designed to test IP-resistivity features between ~250m – 550m downhole as well as the upper central portion of the MT anomaly from ~800m – 1400m.
- Drillhole designed to avoid magnetic inversion models, away from pyrite-magnetite dominated domains, improving potential for porphyry copper sulphide assemblages.
Figure 1. Drilling underway at Target C.
Read the full ASX release from FMR Resources below.
FMR Managing Director, Mr Oliver Kiddie, commented:
“Completion of the downhole geophysical program at Target A has strengthened our understanding of this porphyry system with offhole targets identified as well as a refined position and size of the MT anomaly. Mobilising to Target C allows us to test the MT source where it comes closer to the surface and to target an extensive IP-resistivity window between 250m–550m. Importantly, Target C gives us a second drill point to allow us to vector geological, geochemical, and geophysical datasets.
Our maiden drillhole at Target A confirmed we have identified a large, fertile, porphyry copper system at Southern Porphyry. The next few drillholes have the clear aim of unlocking the mineralised core of this extensive system.”
Geophysical Interrogation
Downhole geophysical datasets acquired from 25LHDD070 at Target A — including IP, EM conductivity, magnetic susceptibility, and spectral gamma — are now being integrated into the Company’s existing 3D MT, IP and magnetic inversion models. This work will refine the geometry, depth extent and position of the MT conductive source interpreted at Southern Porphyry.
The downhole Comprobe data show a consistent pattern that aligns well with the MT inversion model, however logging implies the MT zone is larger than originally modelled . Single-point resistivity decreases toward ~30 Ω·m within the MT-V3 shell, supported by gamma-ray facies changes. The A strong negative self-potential response develops toward end-of-hole, with values approaching -1,000 mV. Elevated M64 chargeability, compared with the more limited MA16 response, indicates increasing off-hole chargeability within the MT-V3 domain. Collectively, these datasets suggest the hole has entered the outer expression of a large sulphide-bearing hydrothermal system, with the main porphyry source interpreted to be located proximal, but not yet intersected.
Target C – Rationale and Drill Design
Target C is defined by a strong MT conductor that is closer to the surface than Target A, offering an opportunity to test the MT response at a shallower, structurally favourable position.
The planned drillhole, 25LHDD071, is designed to:
- Intersect the upper central portion of the MT anomaly,
- Test IP/Resistivity features between approximately 250 m and 550 m downhole, and
- Avoid the pyrite-magnetite dominated zones indicated by the magnetic inversion models.
This spatial offset of the drillhole location provides an improved ability to evaluate sulphide distribution, alteration trends and porphyry-style zonation without drilling directly through magnetite-rich domains that can obscure geophysical and geological vectors.
Figure 2. Cross section C-C’, Target C, showing geophysical models and planned drillhole 25LHDD071 downhole, testing relatively shallow IP-RES and IP Chargeability features, and a large MT high amplitude feature at depth (+/- 10m window)*.
The Full PDF is available below.
News Release
Date: 3 December 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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