Great Southern Copper PLC announced that it has received final assay results for 526 samples from the Phase I and Phase II trenching programmes at its San Lorenzo copper-gold project. Twelve of the thirteen trenches excavated recorded anomalous Cu-Au geochemistry and/or significant widths of variably oxidised porphyry-style sheeted fracturing. Results confirm anomalous porphyry style Cu-Au mineralisation associated with monzonitic intrusives.

Trench CET009 returned anomalous Cu-Au assays ranging from 224ppm Cu to 3.51% Cu over a 57.8m wide interval including visible copper observed over intervals of 20.5m and 17.2m. Confirms potential for higher grade Cu-Au mineralisation; o 3.36% Cu, 2.53 ppm Au and 5.27 ppm Ag from single trench sample recorded in trench CET008. o 1.2% Cu, 14.4 ppm Au from single trench sample recorded in trench CET007 .

o 3.51% Cu, 0.95 ppm Au from a single trench sample recorded in trench CET009 within an anomalous zone of 57.8m . Confirms potential for large mineralised system indicated by extensive oxidised sheeted fracturing. Phase III trenching programme underway designed to in-fill areas of known mineralisation plus test for lateral extensions.

Additional porphyry Cu-Au targets to test. Phase III trenching will also target a zone of clustered monzonite porphyries located 2km west of the current programme. Maiden diamond drilling programme to commence in May-June 2022 subject to rig availability and permitting approvals.

Results have been received for Phase I and II of the San Lorenzo trenching programme comprising thirteen trenches which were designed to test four areas of porphyry Cu-Au style mineralisation and anomalous rock chip geochemistry located within a 7km2 area. The trenches were designed to enhance geological, structural and geochemical information to assist in the targeting of potential drill holes. Previous work by GSC at San Lorenzo identified outcropping evidence of porphyry style Cu-Au mineralisation within a broad zone of calc-potassic altered granodiorite defined by sheeted and stock-worked actinolite-Fe-Ox-magnetite-quartz-K feldspar fractures and regularly intruded by stocks, dykes and finger-porphyries of monzonite to quartz-monzonite composition .

Within each trench, rock chip samples were collected over a 1m x 0.5m panel at the start point of each 5m horizontal interval or a 2m horizontal interval where evidence of copper mineralisation was observed. Samples were delivered by the Company to ALS Global laboratories in La Serena, Chile, where they were prepped for assay. Analyses were then conducted by ALS Global Laboratories in Lima, Peru for Au by 30g fire assay with ICP-AES finish, and 48 additional elements, including copper, by ICP-MS using a standard 4 acid digest.

Where copper mineralisation is visible it typically occurs as green oxides hosted within fine fractures of actinolite-magnetite-quartz-K feldspar. Individual Cu assay values across the trenches range from a low of 114 ppm Cu up to a maximum of 3.51% Cu where oxide copper is sampled. Sulphide copper was observed in only three samples with copper assay values of 424 ppm Cu, 3.36% Cu and 3.51% Cu.

Trench CET009 in the south of the project area targeted significant copper in rock-chips where mineralised fractures are observed overprinting an intrusion of monzonite. Monzonite stocks, occurring in clusters of small porphyries across the project area, are interpreted potentially to be the mineralising intrusives to the calk-alkalic Cu-Au porphyry system at San Lorenzo. Oxide copper is observed in CET009 over a 48.3m interval with copper assays ranging from 438 ppm Cu to 3.51% Cu.

Coincident anomalies for Au and Ag occur over the same 48.3m interval. Samples 10-20m either side of the visible copper zone within the monzonite of Trench CET009 are described as "leached" and range in copper values from 147-975 ppm Cu. Trench CET009 was the only trench in Phases I-II that targeted mineralisation hosted in monzonite.

Trench CET010 located 400m to the east of CET009 records anomalous Cu-Ag-Au over a 100m interval associated with oxidised fractures hosted in biotite granodiorite. Deep surficial weathering across the project area at San Lorenzo potentially acts to strip copper and other metals from the surficial oxide zone. Hence, where iron oxide-rich fractures occur adjacent to similar fractures hosting copper mineralisation, it may be relevant to interpret that the iron-oxides on such fractures are a result of the weathering process and as such these fractures may potentially host sulphides at depth.

Trenches CET001 to CET005, located approximately 1.8km north of Trench CET009, targeted anomalous rock-chip Cu-Au geochemistry in highly weathered biotite granodiorite. All trenches record anomalous Cu-Au; however, the central trench, trench CET002, is notable in that sheeted actinolite-Fe-Ox fractures are mapped over almost the entire 478.5m of the trench. Copper oxide mineralisation is patchy throughout the length of the trench and most prominent between 222 - 242.7m with copper assays ranging from 342 ppm to 0.25% Cu.

However, anomalous copper associated with the oxidised fracture sets is also evident over the full length of the trench and most prominent between 105 - 202m and 222 - 330m with assays ranging up to 864 ppm Cu, 0.21ppm Au and 0.57 ppm Ag. Hence, in the weathering profile, copper and other elements are observed to have been significantly depleted although trace quantities remain in anomalous concentrations. A further 1.8km northeast of CET002 trenches CWT001 and CWT002 targeted anomalous rock-chip Cu-Au geochemistry associated with small monzonitic plugs intruding inner calc-potassic altered biotite granodiorite adjacent to the eastern margin of the Chinchillon Fault.

Sheeted actinolite-Fe-Ox fracturing with narrow monzonitic dykes associated with anomalous Cu-Ag-Au geochemistry is prominent throughout the full length of both trenches, although oxide copper mineralisation is uncommon. Anomalous assays range up to 0.16% Cu, 0.27 ppm Au and 11.65 ppm Ag in CWT002 and up to 0.8% Cu, 0.16 ppm Au and 6.77 ppm Au in CWT001. Silver geochemistry is notably more consistent in this area of the project.

On the west side of the Chinchillon Fault, 150-200m west of trench CWT002, trench CWT003 tested silica-clay-pyrite altered diorite intruded by mafic dyke rocks. Assay results show only weak anomalism for copper with sampling results up to 345 ppm Cu.