Diamond Drilling Commences at Artemisa Prospect
Summary by AI BETAClose X
THIS ANNOUNCEMENT CONTAINS INSIDE INFORMATION AS STIPULATED UNDER THE UK VERSION OF THE MARKET ABUSE REGULATION NO 596/2014 WHICH IS PART OF ENGLISH LAW BY VIRTUE OF THE EUROPEAN (WITHDRAWAL) ACT 2018, AS AMENDED. ON PUBLICATION OF THIS ANNOUNCEMENT VIA A REGULATORY INFORMATION SERVICE, THIS INFORMATION IS CONSIDERED TO BE IN THE PUBLIC DOMAIN.
09 November 2026
Great Southern Copper plc
(“GSC” or the “Company”)
Diamond Drilling Commences at Artemisa Cu-Mo Prospect
Scout RC Drilling Results Vector Porphyry Cu Exploration to La Colorada Lithocap, Especularita
Great Southern Copper plc (LSE: GSCU), the company focused on copper-gold-silver exploration in Chile, is pleased to announce the start of drilling targeting Cu-Mo mineralisation discovered in Reverse Circulation (“RC”) drilling at the Artemisa prospect, plus provide an update on the results of its scout RC drilling programme around the margins of the La Colorada Lithocap at its Especularita project.
Highlights:
- Scout RC drilling results deliver a Cu-Mo discovery and “walk up” drill target at Artemisa and vectors future exploration toward potentially larger system beneath the La Colorada advanced argillic lithocap
-
Phase I diamond drilling has commenced at Artemisa following up Hole ART26-RC009 which intersected significant Cu-Mo mineralisation from surface including1
- 106 metres (“m”) @ 0.33% Cu and 42ppm Mo from surface, including;
- 54m @ 0.54% Cu and 66ppm Mo
- Diamond drilling to provide geological control (2 holes, 500m) to the earlier scout RC results at Artemisa
- Porphyry copper style potassic alteration also intersected at Piedras Blancas, providing a very strong eastward exploration vector towards the La Colorada lithocap
- Gold-base metal veins intersected in RC drilling at Victoria and Artemisa South provide a strong northward exploration vector for potential porphyry copper mineralisation beneath the La Colorada lithocap
- Compilation of lithocap data is in progress to guide first pass scout drilling through the La Colorada lithocap to target large-scale porphyry copper systems
- GSC holds rights to own 100% of the Especularita project, including the Artemisa and lithocap prospects
- Prospect located at low elevation with excellent access to infrastructure and mining services and along trend of major copper deposits including Los Pelambres, Altar and El Pachon.
Sam Garrett, Chief Executive Officer of Great Southern Copper, said: "We are very excited to announce that drilling has also now commenced at Artemisa, where earlier this year the Company discovered porphyry Cu-Mo mineralisation as part of its reconnaissance RC drilling programme targeting porphyry-style alteration identified around the southwest margins of the La Colorada lithocap. This short, two-hole programme is designed to provide geological control to the RC drilling and will be followed by a more extensive RC drilling campaign.
“The discovery at Artemisa is very significant for several reasons, namely; it supports GSC’s working hypothesis that the La Colorada lithocap alteration is developed above a porphyry copper mineral system, the outer extent of the lithocap alteration has been eroded, potentially exposing the upper zones of porphyry copper systems, mineralisation in hole RC009 occurs from surface and is of potential economic grade, and the prospect occurs at low altitude, near to the coast and to infrastructure and mining support services.
“Beyond the discovery in hole RC009, the overall results of the scout RC survey have been highly successful, providing very strong exploration vector information indicating that the southwest corner of the La Colorada lithocap is highly prospective for buried porphyry copper systems. Detailed mapping and data compilation of this area of the lithocap are now underway to guide the design of the first drilling programme of the lithocap itself, which we plan to commence within the next 3-6 months.”
La Colorada Porphyry Lithocap, Especularita Project:
The Company’s Especularita Project is centred upon the La Colorada lithocap (Figure 1), a giant high-sulphidation advanced argillic alteration system that is highly prospective for concealed porphyry copper deposits as well as other porphyry-related types of mineralisation which may occur within or marginal to the lithocap environment. These include the advanced Cerro Negro prospect, located on the eastern side of the lithocap, where in 2025 the Company discovered high-grade Cu-Ag mineralisation beneath the old Mostaza mine workings.
The Project is situated at low altitude within the Cretaceous-age coastal metallogenic belt, within a northwest-southeast trending structural lineament that links the Project with notable large-scale porphyry Cu-Au mines and projects, including Los Pelambres, Altar and El Pachon (Figure 1).
Figure 1: GSC’s Especularita Project is located at low altitude within the coastal metallogenic belt of northern Chile and within 50km radius of over 50Mt of contained copper metal defined in mines and advanced projects.
Whilst the La Colorada lithocap covers a vast area (>75km2), previous work by GSC geologists has also identified porphyry-related silica-sericite-pyrite (phyllic) alteration outcropping over large areas surrounding the lithocap suggesting that the high sulphidation alteration potentially once extended further to the west and south well beyond its present limits and has since been eroded possibly exposing the upper zones of porphyry copper systems.
To evaluate this idea GSC designed a “Proof-of-Concept” reconnaissance drill programme comprising 17 scout RC holes (2,474m) testing four target areas on the western and southwestern flanks of the advanced argillic lithocap alteration including Piedras Blancas2, Artemisa North3, Victoria4 and Artemisa South5 (Figure 1).
The scout RC programme was completed in July 2026 and successfully demonstrated that phyllic-altered rocks mapped at the margins of the lithocap are related to porphyry alteration systems and, more significantly, that porphyry Cu-Mo mineralisation associated with potassic (biotite-magnetite) alteration was discovered at surface with hole ART26-RC009 intersecting 106m at 0.33% Cu and 42ppm Mo1. Whilst the hole RC009 results represent a walk-up porphyry Cu-Mo drill target, the results from RC holes at Piedras Blancas, Artemisa South and Victoria provide strong exploration vectors indicating an increase in alteration intensity toward (and beneath) the La Colorada high-sulphidation lithocap.
Diamond Drilling Commences at Artemisa Cu-Mo Prospect:
Diamond drilling has commenced at Artemisa where hole ART26-RC009 intersected over 100m of highly anomalous Cu-Mo mineralisation. A short programme of two scout diamond holes (500m) is planned to provide geological control to hole RC009 which intersected 106m of 0.33% Cu and 42ppm Mo from surface, including 54m of 0.46% Cu and 66ppm Mo from 16m1 (Figure 2). Diamond hole ART26-DH018 is in progress behind hole RC009 and drilling at a steeper angle to provide detailed geological information including the lithologies, alteration, and mineralisation, and their spatial and temporal relationships; critical information not available from reverse circulation drilling which is essential for planning the next stage of exploration. A second hole is planned to test the vein alteration and mineralisation mapped in an orthogonal direction to the veining and fracturing intersected in holes RC009 and DH018.
Figure 2: Planned diamond drilling at Artemisa for hole ART26-DH18 (l), outcropping evidence of potential porphyry style vein alteration identified at Artemisa (r).
The diamond drilling programme will be followed by a second, more extensive phase of RC drilling (2,000m), subject to results of the scout diamond drilling.
Scout RC Drilling Programme:
At Piedras Blancas, located approx. 1.2km north of hole RC009 (Figure 3), holes RC001, RC002 and RC004 intersected andesite volcanics intruded by diorite, quartz diorite and monzodiorite. From surface, intense phyllic alteration and quartz-pyrite veinlets grade at depth into potassic alteration3 dominated by secondary biotite and characteristic biotite veinlets (or EB veins). RC003 was lost at shallow depth and twinned by RC004. Anomalous assay grades of Cu, Au and Mo are consistent with a distal position in a porphyry system (Table 1). West and north of Piedras Blancas outcropping veinlet-hosted propylitic alteration with anomalous Pb and Zn indicates that the porphyry centre lies to the south (Artemisa North) and or to the east (La Colorada). At present, Piedras Blancas is interpreted to represent the distal top of a porphyry copper system at the transition from phyllic to potassic alteration zones on the edge of the now eroded lithocap. Importantly, this drilling suggests that the base of the lithocap and top of the porphyry copper environment has been identified shallower than expected which has significant implications for drilling below the La Colorada high sulphidation lithocap alteration.
Drilling at Artemisa North targeted a cluster of artisanal workings located west of the La Colorada lithocap and in close juxtaposition to unaltered granodiorite of the Quilitapia Batholith (Figure 3). At surface the alteration is associated with distinctive black manganese-copper stained phyllic alteration. Holes RC005 - RC007 were drilled to the north of hole 009, along the strike of NS trending mine workings. Hole RC008 was drilled further east towards the lithocap. All holes intersected secondary biotite-magnetite alteration (potassic) overprinted by local chlorite-sericite alteration and narrow zones of disseminated and veinlet pyrite-chalcopyrite mineralisation (Table 1). Hole RC009 intersected significant Cu-Mo mineralisation (Table 1) associated with a distinctive low hill of phyllic-altered intrusives with shallow artisanal workings (Figure 2). The mineralisation and alteration remain open to the east and northeast towards the La Colorada lithocap, and to the north where it is interpreted to merge with the Piedras Blancas alteration zone (Figure 3).
Scout holes RC011 - 014 tested the Victoria target1,4 (Figure 3) and intersected microdioritic intrusives overprinted by strong biotite-magnetite alteration. The potassic alteration is cut by structurally-controlled, metric wide zones of quartz-carbonate-hematite vein breccia hosting anomalous pyrite, chalcopyrite and bornite mineralisation with minor Ag, Pb, Zn and Ba (Table 1). Previous reported talus and soil sampling6,7 suggest that the quantity, thickness and grade of the veins increases towards the north towards the La Colorada lithocap. Hematite and or magnetite mineralisation and green-grey chlorite-sericite alteration is not uncommon in diorite-related porphyry copper systems, and we interpret that these vein-breccias are distal to, and have their fluid source from the north below the La Colorada lithocap.
At Artemisa South scout holes RC015, RC016 and RC017 (Figure 3) tested below a swarm of NNE trending artisanal mines with Cu oxides and quartz-specular hematite vein-breccias with green-grey chlorite-sericite alteration haloes hosted in fresh granodiorite of the Quilitapia Batholith. The vein-breccias are similar those seen at Victoria but with less Fe oxides, perhaps reflecting the Fe-poor host rocks. Only rare narrow intervals of mineralisation averaging 2m of about 0.1 % Cu were intercepted (Table 1). In general, the quantity and thickness of the mineralised structures seems to increase north towards the La Colorada lithocap, which is interpreted to be the source of the mineralising fluids.
Figure 3: Geology and summary drill hole plan map for the scout RC programme, Especularita Project (left). Photograph (right) shows the mineralised microdiorite at Artemisa North in the foreground with black oxide copper staining and hills of the advanced argillic altered La Colorada lithocap in the background.
|
Hole ID |
From (m) |
To (m) |
Interval (m) |
Cu (%) |
Au (g/t) |
Ag (g/t) |
Mo (ppm) |
Zn (%) |
|
ART26-RC005 |
22 |
38 |
16 |
0.15 |
|
|
|
|
|
ART26-RC005 |
34 |
38 |
4 |
0.28 |
|
|
|
|
|
ART26-RC006 |
74 |
76 |
2 |
0.21 |
|
|
|
|
|
ART26-RC008 |
24 |
30 |
6 |
0.16 |
|
|
|
|
|
ART26-RC008 |
80 |
84 |
4 |
0.21 |
|
|
|
|
|
ART26-RC008 |
110 |
120 |
10 |
0.2 |
|
|
|
|
|
ART26-RC009 |
0 |
106 |
106 |
0.33 |
|
|
41.6 |
|
|
ART26-RC009 |
16 |
70 |
54 |
0.46 |
|
|
66.4 |
|
|
ART26-RC009 |
122 |
128 |
6 |
0.16 |
|
|
16.6 |
|
|
ART26-RC009 |
136 |
140 |
4 |
0.2 |
|
|
|
|
|
ART26-RC009 |
150 |
154 |
4 |
0.13 |
|
|
|
|
|
ART26-RC011 |
6 |
20 |
14 |
0.23 |
0.18 |
|
|
|
|
ART26-RC011 |
38 |
40 |
2 |
0.64 |
0.14 |
6.9 |
|
|
|
ART26-RC012 |
98 |
104 |
6 |
0.23 |
|
|
|
0.33 |
|
ART26-RC013 |
60 |
62 |
2 |
0.58 |
|
|
108.5 |
|
|
ART26-RC013 |
152 |
162 |
10 |
0.2 |
|
|
|
0.92 |
|
ART26-RC013 |
152 |
158 |
6 |
0.3 |
|
4.3 |
|
1.37 |
|
ART26-RC013 |
154 |
156 |
2 |
0.66 |
|
8.2 |
|
|
|
ART26-RC014 |
2 |
24 |
22 |
0.18 |
|
|
|
0.19 |
|
ART26-RC014 |
16 |
24 |
8 |
0.35 |
|
3.1 |
|
0.2 |
|
ART26-RC014 |
20 |
22 |
2 |
0.79 |
|
3.3 |
|
0.21 |
|
ART26-RC015 |
68 |
70 |
2 |
0.27 |
|
|
|
|
Table 1: Significant mineral intercepts from scout RC drilling at Especularita.
Next Steps:
The RC drilling results provide strong alteration vectors toward the southwestern portion of the lithocap being a significant exploration target for porphyry copper mineralisation. Detailed mapping of this area of the lithocap is in progress (Figure 4) which, combined with analysis of gridded soil geochemistry and ASD mineral spectroscopy, is designed to provide alteration temperature and pH maps of the lithocap vectoring drilling programmes to target the hot, acid areas of the lithocap which potentially sit above the porphyry copper systems below. First drilling beneath the lithocap is planned for the next 3-6 months.
Diamond drilling at Artemisa is currently in progress to provide geological control to the Cu-Mo assay results received in hole ART26-RC009 which were consistent with porphyry Cu-Mo type mineralisation. Subject to the results of the diamond drilling an extensive follow-up RC drilling campaign is planned to drill out the near-surface extent of Cu-Mo mineralisation at Artemisa.
Figure 4: Detailed mapping of the southwest quadrant of the lithocap has identified features consistent with the upper high sulphidation zone of a porphyry copper system including, from left to right; limonite stockwork and disseminations after leached pyrite; translucent porphyry-epithermal quartz vein; breccia pipes with limonite and lesser quartz matrix.
RC Drill Sampling Procedure:
A first-pass “Proof-of-Concept” test comprising 17 holes and 2,474m of RC drilling was completed across 4 prospects surrounding the western and southern margins of the la Colorada lithocap, namely Piedras Blancas, Artemisa North, Artemisa South and Victoria.
The RC drilling method employed at Especularita collected samples on two-metre intervals. Representative samples for each sample of the cuttings are collected in large, individually numbered plastic bags, which are then weighed and transferred to a riffle splitter where they are separated (or split), and homogenised, three times into two duplicate samples of approximately 5kg each. GSC personnel then ticket and label one of the ±5kg samples using preprinted ticket books.
Finally, standard reference materials (“SRM’s” or “Standards”), blanks, and duplicate samples are inserted into the sample sequence for the purpose of quality assurance / quality control (“QAQC”). The second ±5kg sample is used for geological description and stored on site for reference. An additional “hand-specimen” reference selection of cuttings for each two-metre sample is also retained in labelled boxes as a record of the geology of the drill hole.
At the completion of each hole, the representative 5kg samples are transported as a batch from the field and delivered by Company employees to ALS Laboratories in Santago or La Serena where they are prepared for analysis (weighed, dried, crushed and pulverised). A subsequent 200g split of each sample pulp is then forwarded to the ALS geochemical laboratory in Lima, Peru, where samples are assayed for gold (30g fire assay with ICP-AES finish, ALS code AU-ICP21) and 48 major, base and trace elements by ICP-MS following a four-acid digest (ALS code ME-MS61).
RC drilling was selected for this initial proof-of-concept stage as it is faster and cheaper than diamond drilling and allows for the rapid testing of more targets for the same cost.
References:
- RNS 8555S (01 September 2026): Scout RC Drilling Results Confirm Porphyry Copper Mineralisation at Especularita
- RNS 0949B (20 April 2026): Drilling Commences with First Test of Porphyry Copper Targets at Especularita
- RNS 1366E (13 May 2026): Scout RC Drilling Commences at Artemisa North Porphyry Copper Target
- RNS 5465G (02 June 2026): Scout RC drilling commences at Victoria target
- RNS 3799I (16 June 2026): Scout RC drilling commences at Artemisa South copper-gold target
- RNS 0032C (05 February 2024): Rock Chip Sampling at Victoria Prospect Delivers Assay Results up to 4.04% Cu, 4.16g/t Au and 26.7g/t Ag from Multiple Quartz-Sulphide Vein Breccias
- RNS 0445V (03 April 2023): Rock Chip Assay Grades up to 6.9% Cu and 1.85g/t Au in Outcrop from Victoria Prospect
Engage with the GSC management team directly by asking questions, watching video summaries and seeing what other shareholders have to say. Navigate to our Interactive Investor hub here: https://gscplc.com/
Enquiries:
|
Great Southern Copper plc |
https://gscplc.com/link/eo5YYP
|
|
Sam Garrett, Chief Executive Officer |
+44 (0) 20 7138 3204 |
|
|
|
|
SI Capital Limited |
|
|
Nick Emerson |
+44 (0) 1483 413500 |
|
|
|
|
BlytheRay |
|
|
Tim Blythe / Megan Ray |
+44 (0) 20 7138 3204 GSC@blytheray.com |
Subscribe to our news alert service: https://gscplc.com/auth/signup
Notes for Editors:
About Great Southern Copper
Great Southern Copper PLC is a UK-listed mineral exploration company focused on the discovery of copper-gold-silver deposits in Chile. The Company has the option to acquire mining rights to 100% of Especularita project in the under-explored coastal belt of Chile that is prospective for large scale copper-gold-silver deposits. Chile is a globally significant mining jurisdiction being the world’s largest producer and exporter of copper.
The Especularita Project is located in the coastal metallogenic belt of Chile which hosts significant copper mines and deposits, including Teck’s Carmen de Andacollo copper mine, and boasts excellent access to infrastructure such as roads, power and ports. Significant historical small-scale and artisanal workings for both copper and gold are readily evident in the exploration project area. The coastal belt offers deposit type optionality for copper including porphyry and IOCG style deposits as well as newly recognised intrusive-related copper and gold deposits.
Great Southern Copper is strategically positioned to support the global market for copper – a critical battery metal in the clean energy transition around the world. The Company is actively engaged in exploration and evaluation work programmes targeting both large tonnage, low to medium grade Cu-Au as well as high-grade Cu-Ag-Au deposits.
Further information on the Company is available on the Company’s website: https://gscplc.com
Competent Person Statement
The information in this announcement that relates to exploration results is based on and fairly represents information reviewed or compiled by Mr Sam Garrett, a Competent Person who is a Member of the Australian Institute of Geoscientists and a Fellow of the Society of Economic Geologists. Mr Garrett is the CEO and a shareholder of Great Southern Copper PLC. Mr Garrett has sufficient experience that is relevant to the styles of mineralisation and types of deposit under consideration and to the activity being undertaken to qualify as a Competent Person as defined in the 2012 Edition of the "Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves". Mr Garrett has provided his prior written consent to the inclusion in this announcement of the matters based on information in the form and context in which it appears.
This announcement includes information that relates to Exploration Results prepared and first disclosed under the JORC Code (2012) and extracted from the Company’s previous LSE announcements as noted, and the Company’s Prospectus dated 20 December 2021. Copies of these announcements are available from the LSE Announcements page of the Company’s website: www.gscplc.com.
The Company confirms that it is not aware of any new information or data that materially affects the information included within the Prospectus dated 20 December 2021.
Forward Looking and Cautionary Statements
Some statements in this announcement regarding estimates or future events are forward-looking statements. They include indications of, and guidance on, future earnings, cash flow, costs and financial performance. Forward-looking statements include, but are not limited to, statements preceded by words such as “planned”, “expected”, “projected”, “estimated”, “may”, “scheduled”, “intends”, “anticipates”, “believes”, “potential”, "predict", "foresee", "proposed", "aim", "target", "opportunity", “could”, “nominal”, “conceptual” and similar expressions. Forward-looking statements, opinions and estimates included in this report are based on assumptions and contingencies which are subject to change without notice, as are statements about market and industry trends, which are based on interpretations of current market conditions. Forward-looking statements are provided as a general guide only and should not be relied on as a guarantee of future performance. Forward-looking statements may be affected by a range of variables that could cause actual results to differ from estimated or anticipated results and may cause the Company’s actual performance and financial results in future periods to materially differ from any projections of future performance or results expressed or implied by such forward-looking statements. So, there can be no assurance that actual outcomes will not materially differ from these forward-looking statements.
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