⚒️ Southern Hemisphere Mining Limited is pleased to announce an increased JORC Mineral Resource Estimate (“MRE”) update for its Llahuin Copper-Gold-Molybdenum Project (“Llahuin Project”) in central Chile.
⚒️ Executive Summary
The Llahuin MRE totals 218Mt at an average grade of 0.38% CuEq (at a 0.22% CuEq cutoff grade) as tabulated below and includes 496,600t of Copper 654,900oz of Gold and 12,500t of Molybdenum.
Metal recoveries have not been applied in the CuEq calculation which is based solely on metal prices. The CuEq is provided as a comparative tool only and should not be used for economic valuation.
⚒️ HIGHLIGHTS
- Mineral Resource Estimate (MRE) for the Llahuin Copper-Gold Project of 218Mt at an average grade of 0.38% CuEq
- MRE is across three deposits, with strong potential to define further resources (refer to new Exploration Target)
- Progressing towards mine scale open pit configuration
⚒️ Southern Hemisphere’s Chairman Mr Mark Stowell commented:
“We are delighted to report this Mineral Resource update which is a compliment to our team’s work over the past 4 years at Llahuin.
The JORC Resource underpins the future potential of this project over a substantial strike of ~4km with our shallow drilling adding to the from- surface resources and prospects. This does two things, first: to continue advancing towards mine scale and secondly: the potential of this system that can produce large tonnages at surface over such strike length has a high probability of substantial copper endowment at higher grades deeper. We will initially test this at the Curiosity-Southern Porphyry scheduled for drilling in Q4 2025 with FMR Resources Limited (ASX: FMR).
We see considerable scope for resource growth at Cerro-Ferro including the Ferro West MT target, and the recent discovery at Ferro South given shallow drilling to date in these areas. Our Exploration Target is ~260-340Mt in addition to the 218Mt JORC Resource.”
⚒️ A large proportion of the recent drilling has consisted of in-fill drilling, which resulted in upgrading a significant amount of material previously classified as Indicated to the Measured Resource category.
The resource now stands at 218Mt grading at 0.38% CuEq (at a 0.22% CuEq lower cut-off).
Drilling in recent years has focused on extending the Cerro-Ferro deposit which now demonstrates with soil geochemistry that it is part of one system. A revised drilling orientation was designed to intersect more of the high-grade NNE trending, ESE dipping vein systems which host the gold at Cerro.
Recent interpretation of the drilling data has identified key areas for higher grade depth extensions of known mineralization for future deeper diamond drilling. The Ferro South discovery was made in late 2024, and due to the consistent thickness and grade became an additional focus area to establish a maiden JORC-compliant resource.
In addition to the current MRE of 218Mt @ 0.38% CuEq (at a 0.22% CuEq cut-off), the Company has delineated an Exploration Target of between 260Mt and 340Mt, with grades ranging from 0.20% to 0.30% Cu, 0.08 to 0.10g/t Au, and 50 to 60ppm Mo.
This Exploration Target is exclusive of the current MRE and excludes the Curiosity-Southern Porphyry Target.
Drilling of the Curiosity-Southern Porphyry is scheduled for Q4 2025. More details below.
⚒️ Llahuin Copper-Gold-Moly Project Location, Resource Block Model Cross Sections and Plan Views.
The June 2025 MRE update includes the most recent drilling up to January 2025.
The Company engaged Hyland Geological and Mining Consultants (“HGMC”) to complete the MRE for the Llahuin Project. The Llahuin MRE is reported in accordance with the JORC (2012) Code and is detailed in Table 1 attached to this announcement by resource classification, and illustrative plans and cross sections are shown below. Mr Hyland is also the relevant Competent Person as defined in the JORC (2012) Code, for the reporting of the Llahuin Exploration Target.
Figure 1 – Llahuin Copper-Gold-Moly Project Location Map in Chile
Figure 2. Llahuin Total Resources 0.2% CuEq grade shell (Looking NE). Grid size 0.5km x 0.5km.
Figure 3. Concession outline, deposit locations and section lines (Figure 4 – Central Deposit cross section, Figure 5 – Cerro-Ferro long section and Figure 9 -Ferro South cross section).
Figure 4. Central Deposit cross section showing ore blocks by grade range (Refer Figure 3).
Figure 5. Cerro-Ferro long section (Refer Figure 3).
Figure 6. Central Deposit Block Model resource categories. Grid size 250m x 250m (yellow = measured, pink = indicated, light blue = inferred and dark blue = unclassified).
Figure 7. Cerro Block Model resource categories, looking ESE (125 degrees). Grid size 250m x 250m (yellow = measured, pink = indicated, light blue = inferred and dark blue = unclassified).
Figure 8. Ferro Block Model resource categories. (Looking West), grid size 250m x 250m. (yellow = measured, pink = indicated, light blue = inferred and dark blue = unclassified).
Results at Llahuin continue to demonstrate consistency of thickness, with the depth from surface to the current vertical limit still limited by drilling. Only Central has been systematically drilled well below 200m vertical with copper-gold-moly mineralisation still remaining open at depth.
Figure 9. Ferro South Block Model cross section showing ore blocks by grade range (Refer Figure 3).
⚒️ Measured, Indicated and Inferred resources as at June 2025 the data cut-off date:
A cut-off grade of 0.22% CuEq was selected to report the resource as the resultant head grade of 0.38% CuEq is considered to have a reasonable likelihood of being economic based upon internal cost and revenue calculations made by the Company.
Resources are reported above a copper equivalent (CuEq) cut-off grade of 0.22% CuEq. The CuEq calculation is based on metal prices of US$3.50/lb Cu, US$3,000/oz Au, and US$20/lb Mo. No recoveries have been used as metallurgical testwork is still to be optimised. Preliminary metallurgical recoveries from closed circuit flotation testwork confirmed no deleterious elements: Cu 84–91%, Au 41–57%, Mo ~14–56%. CuEq formula: Cu % + (Au g/t × 1.25) + (Mo % × 5.7). Metal recoveries have not been applied in the CuEq calculation which is based solely on metal prices. The CuEq is provided as a comparative tool only and should not be used for economic valuation.
Figure 10. View from top of Curiosity-Southern Porphyry over Llahuin (Looking NE) with Ferro drill pads in the hill opposite.
⚒️ Curiosity-Southern Porphyry is a large target south of Ferro that has been studied with a wide variety of geophysical, magnetics, and litho-geochemistry techniques and all confirm a substantial target. Southern Hemisphere has joint ventured the deep drilling of this target with FMR Resources Limited (ASX: FMR) backed by the Creasy Group. Drilling commencing Q4 2025.
Figure 11. 3D view of the Llahuin Project, drilling to date forming the basis of the JORC Resource, and the Southern Porphyry Target (under JV with FMR) showing 3D inversion model resistivity shells from magnetotelluric data. (Blue tenement outline is FMR JV).
The following table is a summary of the Measured, Indicated and Inferred resources as at June 2025 the data using a Copper Only (Cu%) lower cut-off basis:
A cut-off grade of 0.20% Cu was selected to report the copper only basis resource to confirm the copper metal content is of significant quantity and also demonstrates reasonable prospects for economic exploitation based on the aforementioned working internal cost and revenue estimates.
⚒️ ASX Listing Rule 5.8.1 Summary
Southern Hemisphere Mining Limited (“Southern Hemisphere” or “the Company”) (ASX: SUH) is pleased to provide a comprehensive summary of the updated Mineral Resource Estimate (“MRE”) for its Llahuin Copper-Gold Project (“Llahuin Project”), located in the Coquimbo Region of central Chile. This summary is provided to comply with ASX Listing Rule 5.8.1 and is based on the updated JORC Table 1 (June 2025) and supporting technical data.
Project Description
Location
The Llahuin Project is located close to the city of Illapel, in the Coquimbo Region, 350km north of Santiago in Chile, at an elevation of ~1,300 metres above sea level. The area is well served by infrastructure, including roads, and is also just 5km from the electricity grid and 20km from the nearest sealed airstrip. In addition, a disused railway passes through the property. Despite the semi-arid climate, the Llahuin Project is not in a critical water vulnerable area, and although there has been a severe drought over recent years the Company has intersected water (non-potable) in all holes at an average depth of 60m. Nearby ports include Coquimbo, some 200km by road to the NW, and which supports the Andacollo operation of Teck, and Los Vilos, 150km by road to the south-west, which supports the Los Pelambres mine, owned 60% by Antofagasta PLC. Being in a recognised mining district (and country), there is ready access to skilled services and suppliers, as well as personnel, from unskilled labour to professionals.
Figure 12. Central and Northern Chile with the Llahuin Copper-Gold Project showing metallogenic belts, significant deposits, and interpreted structures.
Regional Setting
Llahuin is located on a SE-trending structure that appears to terminate the southern end of the Eocene/Oligocene belt (which hosts Escondida to the north), and the northern end of the Miocene belt, which hosts Los Pelambres 66km to the SE amongst many other copper deposits. These structures are important for localising intrusive complexes and hence mineralisation. Overprinting relationships indicate at least two stages of mineralisation, with at least the Central Porphyry having an epithermal overprint. The deformed Early Cretaceous volcano-sedimentary rocks include the Arqueros Formation; comprising volcanic flows and andesitic breccias with interbedded sandstone and epiclastic breccias; and the concordant Quebrada Marquesa Formation; comprising chemical and clastic sediments, including marls, shales, sandstones, conglomerates and gypsum. The volcano-sedimentary units form an east-dipping homocline, and are cut by three main fault sets, namely NE-SW, N-S and NW-SE. These are generally steeply dipping and are considered important as structure appears to have played a major part in controlling the location of the major intrusives.
Geology and Geological Interpretation
The Llahuin Copper-Gold Project is a porphyry copper-gold-molybdenum system with associated IOCG-style mineralisation, hosted within Cretaceous intrusive stocks and surrounding volcanic units. Three main zones comprise the Mineral Resource: Central Porphyry, Cerro De Oro, and Ferrocarril. Detailed mapping, structural interpretation, drone magnetics, IP Survey, geochemical sampling and recent Audio-Magnetotelluric (AMT) surveys have refined the structural and lithological controls, confirming an extensive porphyry footprint consistent with Andean porphyry deposits. High-grade mineralisation is associated with well-developed quartz stockwork and potassic alteration within dioritic and granodioritic intrusions. Porphyry-style Cu-Au-Mo mineralisation occurs along a +2.5km N-S strike (open north and south, with a total strike length of up 6km). These zones are coincident with a north-south trending valley, potentially reflecting weathering of more regressive units or a structure.
Figure 13. – Location Map showing the Llahuin Cerro and Ferro and Ferro South Zones 2024 drilling in red, 2023 drilling in white, prior drill collars in black, and geochemistry.
Drilling Techniques, Data Density and Other Work
Llahuin was initially acquired in July 2011 by Southern Hemisphere through an intermediary from Antofagasta PLC. Drilling completed across the total project to date comprises 296 holes for 64,503m. The deposit RC and Diamond drilling breakdown is provided below.
The above drilling supports the current estimate, comprising HQ3 triple-tube diamond core drilling and face-sampling RC drilling with 5.25-inch bits. Collars were surveyed by licensed Chilean surveyors using RTK DGPS with centimetre precision. Downhole gyroscopic surveys were completed for all recent diamond holes to ensure minimal deviation. Core orientation was routinely conducted using Reflex digital tools to facilitate structural logging for more recent diamond drilling. Drilling density in key resource areas ranges from 20–40m for Measured and Indicated classifications, and up to 100m for Inferred zones. In addition to drilling Southern Hemisphere has completed extensive geochemical and geophysical surveys at Llahuin, including detailed magnetics (MAG), induced polarisation (IP), and magnetotellurics (MT). These datasets have indicated a large “blind” porphyry-style target at the southern end of the Llahuin Project named the Curiosity-Southern Porphyry Target. This target is defined by a coincident magnetic anomaly, IP resistivity anomaly, and MT resistivity anomaly. The target is modelled as a circular feature 1.5km – 2km in diameter and centered approximately 1,000m below surface.
Sampling and Sub-Sampling Techniques
Diamond core was half-cut with a diamond saw, with consistent retention of half-core for reference. RC samples were split at the rig via a cyclone and riffle splitter to achieve representative 2–3kg subsamples. Intervals were predominantly 1–2m, adjusted where geological contacts required. Sample preparation was conducted by ALS Santiago under strict chain-of-custody, involving drying, crushing to <2 mm, and pulverising to >85% passing -75µm. A robust QA/QC protocol included insertion of blanks, duplicates, and certified reference standards at a frequency exceeding 5% of total samples. Umpire check assays were undertaken at a secondary independent laboratory.
Sample Analysis Methods
Gold analyses were conducted by 30g fire assay (AA or ICP-MS finish). Multi-element analyses for copper, molybdenum, and trace elements employed four-acid digestion with ICP-OES or ICP-MS finish. ALS Santiago holds ISO 9001 and ISO/IEC 17025 accreditation. QA/QC results confirm high analytical precision and accuracy across campaigns.
Estimation Methodology
The updated MRE was estimated within 3D wireframes constructed using geological, structural, and assay data, guided by grade shells at nominal 0.1% Cu and 0.1 g/t Au thresholds. Ordinary Kriging interpolation was used for copper, gold, and molybdenum grades within a parent block size of 10 m (E) x 10 m (N) x 5 m (RL). Variogram models and search strategies were optimised for each domain. Validation involved swath plots, statistical comparisons to input composites, and visual inspection of grade distributions.
Metallurgy
Metallurgical recoveries based on historic test work results by ASMIN and analysis by Sedgman:
- Recoveries of copper vary between 75% Cu and 91% Cu with the weighted average of the results being 84% Cu, which is a typically acceptable commercial level.
- Recoveries of gold vary between 41% Au and 57% Au, which is in line with expectations given the relatively low gold grades within the deposit, and noting a constant tail. (so higher grade would expect higher recovery).
- Recoveries of molybdenum vary between 14% and 56% Molybdenum, which would be expected to increase with the addition of specialized moly reagents.
It is the opinion of the Company and the Competent Person that all elements and products included in the metal equivalent formula have a reasonable potential to be recovered and sold based on production from similar porphyry copper mines in Chile.
Metallurgical Test Work Summary
Two phases of test work have been undertaken on samples from the Llahuin Project, the first by ASMIN Industrial, in 2012 – 2013, at ASMIN Santiago and the second by SGS Minerals at SGS Santiago in 2020. Samples derived from selected diamond core composites taken from the Central Porphyry prospect. The program consisted of head assays, specific gravities, bond ball mill work index determinations, bond abrasion index determinations, rougher and cleaner flotation tests, locked cycle flotation tests, and thickening tests. The Company commissioned Sedgman Pty Ltd to undertake a review of the metallurgical test work conducted on the Llahuin Project in 2020. From the Sedgman review the bond ball mill work indices ranged from 12.94 kWh/t to 16.4 kWh/t and averaged 13.89 kWh/t indicating moderate hardness, and a single bond abrasion index of 0.2287 indicate that the ore was moderately abrasive. Locked cycle flotation test work was conducted on the samples using a primary grind size P80 of 140µm and a regrind size P80 of 45µm with two stages of cleaner flotation. These parameters had been determined through sighter test work. The copper recoveries in the locked cycle tests ranged from 73.9% to 89.8% and averaged 81.4%. Flotation concentrates produced during locked cycle testing contained the resource weighted average copper grade of 28% Cu and 4.9g/t Au. For molybdenum the recoveries were sufficient and lower, varying between 13.5% and 56.4%; the low values could be improved by performing an optimization study and adding some molybdenum-specific flotation reagents. They also contained low levels of deleterious materials in the concentrate. Given that these tests were designed to set parameters and were not optimised, the results indicated good flotation process characteristics.
Cut-off Grades and Reporting
Resources are reported above a copper equivalent (CuEq) cut-off grade of 0.22% CuEq. The CuEq calculation is based on metal prices of US$3.50/lb Cu, US$3,000/oz Au, and US$20/lb Mo. No recoveries have been used as metallurgical test work is still to be optimised. Preliminary metallurgical recoveries from closed circuit flotation test work confirmed no deleterious elements: Cu 84–91%, Au 41–57%, Mo ~14–56%. CuEq formula: Cu % + (Au g/t × 1.25) + (Mo % × 5.7). Further test work and confirmation is required before final recoveries are finally applied.
Bulk Density
Bulk density values were determined using the Archimedes method on over 740 core samples, with values ranging from 2.65–2.84 t/m³ depending on lithology and oxidation state. A mean dry bulk density of 2.67 t/m³ was assigned to mineralised domains.
Mining and Metallurgical Factors
A preliminary pit shell was generated using the previously generated Resource Block Model used to report in June 2013. A new pit optimisation has not been applied at this stage on the new June 2025 Resource Block Model but an improved project ‘Net Revenue’ from an optimized pit is anticipated given the more favourable metals prices in force at this time. Historical test work confirms that mineralisation is amenable to conventional flotation, producing clean copper concentrates with minimal deleterious elements and payable gold and molybdenum credits. Further bulk test work, grind size optimisation, and gold recovery enhancement (potential gravity circuit) are planned.
Tenure, Environment, and Social Considerations
All concessions are held in good standing by Southern Hemisphere Mining Limited via its 100%-owned Chilean subsidiaries. A binding 30-year easement agreement is in place with the local El Espino community, securing land access for exploration and potential future mining and infrastructure. No known environmental or legal risks have been identified at this stage that would materially impact the Mineral Resource.
Mineral Tenement and Land Tenure Status
The Llahuin Project is located within the Coquimbo Region of central Chile, approximately 240km north of Santiago, and 17km south of the town of Combarbalá. The Llahuin Project is located 56km east of the coast and the Pan-American Highway. The topographical coordinates of a central point within the project are East 71º 01′ 29” and North 31º 20′ 23” (Datum Long/Lat UTM Projection, International Reference Ellipsoid 1924, La Canoa Datum 1956, Time/Area 19). The Llahuin Project is located within the “Amapola” concessions. These concessions have been granted to Minera Llahuin SCM (MNLLA), a wholly owned subsidiary of Southern Hemisphere Mining Limited.
Recently the Company executed a JV agreement with FMR Resources Ltd (ASX: FMR) for them to earn up to 60% in Amapola 1, 2, 5 and 7, which excludes all existing deposits and extensions thereof. The earn-in includes expenditure of up to $13m over two stages, and payments of up to $2.67m to the Company.
*Copper Equivalent (or “Cu Equiv” or “Cu Equivalent”)
The copper equivalent calculations represent the total metal value for each metal, multiplied by the conversion factor, summed and expressed in equivalent copper percentage. These results are exploration results only and no allowance is made for recovery losses that may occur should mining eventually result. It is the Company’s opinion that elements considered have a reasonable potential to be recovered as evidenced in similar multi-commodity natured mines. Copper equivalent conversion factors and price assumptions for the June 2025 JORC (2012) Resource Update are stated below:
Copper Equivalent Formula= Cu % + Au (g/t) x 1.25 + Mo % x 5.71
Assumptions- Cu (US$3.50/lb), Au (US$3,000/oz), Mo (US$20/lb)
The Company has also recently completed an Exploration Target for the Llahuin Project, which was defined following the generation of the MRE described in this ASX release. The tables below outline the Exploration Target for the Llahuin Project and are reported exclusive of the recent MRE. The Exploration Target with the widest range between Lower tonnes and Upper tonnes and grade ranges reflect the lower amount of drilling data available for these prospects.
The Exploration Target is based on the current geological understanding of the copper mineralisation and endowment at Llahuin supported by >60,000m of RC and diamond drilling, recent MRE modelling, geological and structural mapping, surface IP geophysics, MT Geophysics, airborne geophysical data and interpretation and the comprehensive surface geochemical sampling sets available.
The Exploration Target does not consider factors related to detailed geological complexity, possible mining extraction methods or metallurgical processing or recoveries. This Exploration Target provides an assessment of the potential scale of the Llahuin Project mineralisation beyond the existing MRE and of the work programs needed to convert this Exploration Target into at least an Inferred MRE in the future.
The reported Llahuin Project Exploration Target is defined over three deposit and prospect areas. The majority is based on planned infill drilling between resources and extensions thereof as shown below, and the remainder is unclassified resources based on drill results albeit spacing too wide to classify as inferred.
Figure 15. Exploration target (Blue) and resource shells (Green). MT Targets (pink) (Looking ENE). Grid size 250m x 250m.
Geological Volume and Unclassified Mineralisation
A total of 109,000,000 cubic metres is contained within the interpreted blue wireframe shell, defined using drillhole data, geochemical assays, and geophysical interpretations.
Unclassified mineralised volumes (RCAT = 4) within the three main resource areas are as follows:
- Central Porphyry: 907,000 cubic metres – Unclassified
- Cerro De Oro: 3,310,000 cubic metres – Unclassified
- Ferro Carril: 3,350,000 cubic metres – Unclassified
The combined baseline volume is estimated at 116,600,000 cubic metres (rounded), with a lower range (-10%) (taking into account internal barren intrusives,) tonnage of ~260 million tonnes and an upper range (+20%) of ~340 million tonnes, assuming the same bulk density values used in the current MRE – (Approximately 2.67 tonnes / cubic metre). The Exploration Target has not extended below the depth of the majority of the existing drilling.
Grade ranges for copper, gold, and molybdenum are based on the current MRE and geological interpretations derived from drilling and analytical work completed to date.
The Exploration Target is to be evaluated through staged drilling programs, with the aim of generating JORC-compliant MREs—initially expected to meet the criteria for Inferred classification—within each prospect area or deposit identified. These programs are planned to be undertaken progressively over the coming years.
This Exploration Target is exclusive of the current MRE.
The Exploration Target has been prepared and reported in accordance with Clause 17 of the JORC (2012) Code and disclosed in compliance with ASX Listing Rule 5.7.2.
The potential quantity and grade of the Exploration Target is conceptual in nature. There has been insufficient exploration to estimate a Mineral Resource, and it is uncertain whether further exploration will result in the estimation of a Mineral Resource.
The Exploration Target is based on geological mapping and interpretations, drilling, geophysics, soil sampling geochemistry and Resource Model Interpretation. All relevant material assumptions used in the generation of this Exploration Target are outlined in the body of this announcement and in the accompanying JORC Table 1.
The Exploration Target is reported as a range of tonnes and grade in accordance with the requirements of ASX Listing Rule 5.7.2(a).
Cautionary Statement: The potential quantity and grade of the Exploration Target is conceptual in nature. There has been insufficient exploration to estimate a Mineral Resource in the area considered an Exploration Target (except where noted) and it is uncertain if further exploration will result in the estimation of additional Mineral Resources. The Exploration Target has been prepared and reported in accordance with the 2012 edition of the JORC Code.
Next Drilling
The next drilling program at Llahuin will be in Q4 2025 targeting the deep Curiosity-Southern Porphyry copper target with ~1,400m diamond holes in JV with FMR Resources Ltd. (ASX FMR).
The Full JORC Resource PDF for Llahuin is available below.
News Release
Date: 30 July 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.
For the latest information about the Company – please visit our Latest News and Corporate Profile pages. We are also on LinkedIn and Twitter (X).
