REG - Great Southrn.Copper - GSC Expands Footprint at La Colorada Lithocap

Great Southern CopperAnnouncement

Mon 07:00

For best results when printing this announcement, please click on link below:
https://newsfile.refinitiv.com/getnewsfile/v1/story?guid=urn:newsml:reuters.com:20260413:nRSM1591Aa&default-theme=true

RNS Number : 1591A  Great Southern Copper PLC  13 April 2026

 

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.

 

 

13 April 2026

 

Great Southern Copper plc

("GSC" or the "Company")

 

GSC Expands Footprint at La Colorada Lithocap Porphyry Cu-Au Prospect with New
Concessions

 

Dominant position strengthened over highly prospective and under-explored
target

 

Great Southern Copper plc (LSE: GSCU), the company focused on
copper-gold-silver exploration in Chile, is pleased to announce that it has
increased its concession footprint at the La Colorada Lithocap prospect, part
of the Especularita Project, which is highly prospective for porphyry Cu-Au
type deposits.

 

Highlights:

·    GSC expands footprint at La Colorada with five new concessions
totalling 1000 hectares ("ha"), securing control over the central core of a
large-scale lithocap alteration system

·    Dominant land position further enhanced over a highly prospective and
under-explored porphyry Cu-Au target

·    La Colorada is defined by an over 75km² high-sulphidation lithocap
- a scale capable of hosting multiple porphyry systems

·   Located on a major mineralised trend alongside world-class porphyry
deposits including Los Pelambres, Altar and El Pachon

·   Exploration programmes underway with mapping, sampling and geophysics
designed to vector toward potential porphyry centres at depth

·    Clear pathway towards scout RC drilling, with targeting, planning
and permitting well advanced

·    Company holds rights to 100% of the Especularita Project which
includes the La Colorada prospect

·    The Especularita Project is located in Chile's coastal metallogenic
belt with excellent access to infrastructure and mining support services

 

 

Sam Garrett, Chief Executive Officer of Great Southern Copper, said: "Advanced
argillic high-sulphidation lithocaps are well known to occur above porphyry
copper and copper-gold deposits globally, and GSC's La Colorada prospect is a
giant example with the alteration system extending for over 75 square
kilometres in area. Significantly, La Colorada sits within a lineament that
hosts massive porphyry copper-gold deposits, including Los Pelambres, Altar,
Piuquenes and El Pachon, and yet remains relatively unexplored.

 

"GSC's new concessions, totalling 1,000 hectares, significantly strengthens
our already dominant position over the lithocap and, critically, secures
control of the central core of the alteration system for the Company.

 

"Exploration, including mapping, sampling and geophysics, is planned to
systemically vector towards potential porphyry copper centres at depth. In
parallel, planning and permitting for scout RC drilling targeting the western
and southern margins of the lithocap are well advanced, and we hope to
commence these programmes within the month."

 

La Colorada Porphyry Cu-Au Prospect:

 

Great Southern Copper's Especularita Project is centred around the giant La
Colorada lithocap located within the Cretaceous-age coastal metallogenic belt
of northern Chile. The prospect is defined by its distinctive
high-sulphidation style alteration blanket mapped over an area greater than 75
km(2) within a northwest-southeast trending structural lineament that links
the prospect with notable porphyry Cu-Au mines and projects (Table 1)
including Los Pelambres mine, Altar and El Pachon (Figure 1). To the north the
prospect is on trend of the Carmen de Andacollo porphyry copper (Teck) and
gold mines (Galantas) which, significantly, are developed beneath an advanced
argillic lithocap of similar type and dimension to La Colorada and hosted in
similar aged rocks at similar elevation.

 

 

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.

 

Regional mapping at Especularita suggests that the La Colorada alteration
system is controlled locally by the dominant northwest-southeast trending
Victoria Fault and is off-set by regular late northeast-trending structures.
The Cerro Negro high-grade Cu-Ag deposit is located within a southeastern
dislocated section of the lithocap (Figure 1).

 

The new concessions further strengthen the Company's control over this highly
prospective alteration system and are considered critical as they potentially
occupy the central core to the mineralising system where alteration may be the
most intense (hottest and most acidic).

 

 Deposit                 Company              Stage            Category                      Tonnes (Mt)  Cu (%)  Au (g/t)  Mo (%)  Ag (g/t)
 Los Pelambres(1)        Antofagasta          Operation        All resources incl. reserves  6,047        0.47    0.04      0.017
 Carmen de Andacollo(2)  Teck                 Operation        Mill ore reserves             417          0.34    0.12
                                              Operation        Heap leach ore reserves       1,300        0.29
 Altar(3)                Aldebaran            PFS              M&I Resource                  2,400        0.42    0.07              1.22
                                              PFS              Inf Resource                  1,215        0.37    0.04              1.25
 El Pachón(4)            Glencore             Pre-development  M&I&I Resource                6,000        0.43    -         0.013   2.2
 Los Azules(5)           McEwen               Development      Prov&Prob Reserves            1,023        0.45
                                              Development      M&I Resource                  996          0.26
                                              Development      Inf Resource                  4,239        0.21
 Llauhin(6)              Southern Hemisphere  Exploration      M&I&I Resource                218          0.38*

 

Table 1: Resource information for deposits located along trend of GSC's
Especularita project, Chile. *CuEq grade Cu-Au-Mo

 

Figure 2: La Colorada lithocap in background (looking to the southeast from
Artemisa Prospect) with clay-rich argillic alteration clearly visible and
phyllic type alteration underlying in the foreground being investigated by GSC
geologists. The lithocap includes classic alteration textures, including (l to
r) advanced argillic vughy silica, argillic clay alteration, intense pyrite
alteration (oxidised) and brecciation.

 

Lithocaps and Porphyry Cu-Au Mineralisation:

 

Advanced argillic high-sulphidation lithocaps are well known to occur above
porphyry copper and copper-gold deposits globally although are not widely
observed above deposits in Chile due to the actions of rapid tectonic uplift
and erosion. Notable exceptions include Carmen de Andacollo and Valeriano-El
Encierro (Figure 3).

 

Generally, lithocaps comprise subsurface, broadly stratabound alteration
domains that are laterally and vertically extensive with lateral dimensions
greater than 10 km and thicknesses of more than 1 km, hence they are often
referred to as "blankets". They typically form when acidic
magmatic-hydrothermal fluids rising off a porphyry intrusive at depth react
with wallrocks during ascent towards the paleosurface. Although lithocaps
typically have steeply-dipping structural roots, there is a significant
component of lateral fluid flow involved in their formation, either through
permeable aquifers and/or a well-developed lateral fracture system.

 

Although lithocaps are commonly barren, high sulfidation Au-Ag-Cu
mineralisation typically occurs in silicic altered rocks, either as
stratabound replacements, veins and/or breccia cement. The silica-clay-rich
alteration assemblages are invariably magnetite-destructive and can obscure
the magnetic signature of an underlying porphyry deposit. Pyrite alteration is
ubiquitous in lithocaps and mapping pyrite concentration can be an important
vector indicator. Supergene weathering of pyrite (interaction with surface
water) produces H(2)SO(4,) creating highly acidic fluid conditions which acts
to leach the lithocap of minerals and metals, creating the distinctive and
characteristic vughy silica texture (and may also produce supergene enrichment
blankets at depth).

 

Where present, the broad, flat-lying and chemical inert nature of the lithocap
acts to mask (or blanket) the location of porphyry copper deposits below.
Explorers need to rely on other tools, such as geophysics and clay mineralogy,
to attempt to identify the higher temperature and more acidic parts of the
lithocap that sit above the feeder zones leading to the potassic-altered core
of the porphyry mineralising system at depth (Figure 4). The lithocap may mask
multiple porphyry copper deposits and the buried porphyry copper deposit may
not necessarily be centrally located beneath the lithocap, highlighting the
importance of understanding the lithocap geology and geochemistry (vectoring).

 

Figure 3: Scale comparison of Chilean porphyry copper lithocap relative to
GSC's untested La Colorada lithocap at Especularita.

 

 

Figure 4: Model for porphyry copper deposits below lithocaps.

 

Next Steps:

 

Ground exploration covering the five new concession blocks will be
incorporated into the broader ongoing La Colorada exploration programme
including mapping and sampling. Spectral mapping of alteration minerals will
be key to vectoring toward hot, acidic feeder zones. Geophysics surveys (AMT
and magnetics) are also planned to commence this quarter.

 

References:

 

1.    2025 Annual Report and Financial Statements Antofagasta PLC

2.     2016 Portergeo Report on Carmen de Andacollo,
https://portergeo.com.au/database/mineinfo.php?mineid=mn112

3.    2024 Mineral Resource Estimate Aldebaran Resources

4.    2025 Glencore market release 18Aug2025

5.    2026 Corporate presentation McEwen Mining Inc.

6.    2025 ASX Announcement Southern Hemisphere 30Jul2025

 

 

 

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/ (https://gscplc.com/)

 

 

Enquiries:

 

 Great Southern Copper plc             https://gscplc.com/link/Pmp2ar (https://gscplc.com/link/Pmp2ar)
 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
(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 (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
(http://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.

 

This information is provided by RNS, the news service of the London Stock Exchange. RNS is approved by the Financial Conduct Authority to act as a Primary Information Provider in the United Kingdom. Terms and conditions relating to the use and distribution of this information may apply. For further information, please contact
rns@lseg.com (mailto:rns@lseg.com)
 or visit
www.rns.com (http://www.rns.com/)
.

RNS may use your IP address to confirm compliance with the terms and conditions, to analyse how you engage with the information contained in this communication, and to share such analysis on an anonymised basis with others as part of our commercial services. For further information about how RNS and the London Stock Exchange use the personal data you provide us, please see our
Privacy Policy (https://www.lseg.com/privacy-and-cookie-policy)
.   END  MSCGUGDSDUBDGLX



            Copyright 2019 Regulatory News Service, all rights reserved