お知らせ • Mar 17
Great Southern Copper plc Reports Further Exceptional Assay Results from Phase I Drilling At the Mostaza Mine, Cerro Negro
Great Southern Copper plc reported further exceptional assay results from Phase I drilling at the Mostaza Mine, Cerro Negro. Assay results received for holes CNG25 DD002 - DD005 with significant intervals including; DD005: 12.0m of 4.24% Cu and 369.5 g/t Agfrom 40m, including 7.0m of 5.08% Cu and 449.6 g/t Agfrom 45m, within a broader zone of 21.0m of 2.88% Cu and 246.7 g/t Agfrom 35m. DD003: 13.0m of 2.48% Cu and 198.1 g/t Agfrom 39m, within a broader zone of 18.6m of 1.85% Cu and 146.6 g/t Agfrom 36.6m. DD002: 4.2m of 1.73% Cu and 126.5 g/t Agfrom 38.9m. New results demonstrate continuity of high grades building upon earlier reported assays for hole CNG25 DD001; DD001: 20.0m of 3.31% Cu and 269.9 g/t Agfrom 27m, including 7.0m of 5.72% Cu and 489.6 g/t Agfrom 31m. Assay grades consistently significantly higher than reported results of historical drill program
Mineralisation remains open in all directions. Assay results for remaining Phase I drill holes, CNG25 DD006 - 009, are pending. Phase II diamond drilling in progress aiming to expand on historically reported resources and test exploration targets. GSC holds option to own 100% of the Mostaza mine and Cerro Negro project. Prospect located at low elevation with excellent access to infrastructure and mining services. Results of diamond drillholes CNG25 DD002 - DD005: Diamond drillholes CNG25 DD002 - DD005 were designed to target shallow extensions of the historical Mostaza Lens 2 mineralisation at depth and along strike of the intercept in CNG25 DD001. Due to access and safety limitations in the old mine pit the five holes were drilled in a fan pattern from a centrally located drill pad and were planned to intersect the mineralised body on an approximate grid pattern. All holes intersected the Lens 2 mineralised body over varying widths and significant assays. The mineralisation is also weakly anomalous in Sb-As and exhibits pathfinder anomalism for Bi-Cd-Li-Zn which is consistent with the high-sulphidation style of mineralisation. Drillhole CNG25 DD002 was drilled to intersect the lens approximately 25m north of hole DD001 and returned 4.2m @ 1.73 % Cu, 126.5 g/t Ag, and 0.0824 % Sb from 38.9m. CNG25 DD003, which was designed to test the lens below hole DD002, intersected 18.6m @ 1.85% Cu, 146.58 g/t Ag from 36.6m, including 13m @ 2.48 % Cu, 198.09 g/t Ag from 39m, with maximum grades of 1m @ 4.64 % Cu, 406.00 g/t Ag, and 0.22% Sb from 50m. These results appear to demonstrate that both Cu-Ag grade and thickness the lode is increasing with depth. Hole CNG25 DD005 was drilled below hole DD001 and intersected broad intervals of high-grade Cu-Ag similar to mineralisation seen in hole DD0011 including 7m @ 5.08 % Cu, 449.57 g/t Ag from 45m, and 2m @ 6.05 % Cu within a broader lens-wide zone of 21m @ 2.89 % Cu, 246.71 g/t Ag from 35m. Maximum grades of 6.2 % Cu, 567 g/t Ag, and 0.23 % Sb are reported over 1m. Hole CNG DD004 was drilled to the north of DD002 and intersected only weakly altered and mineralised "proto-lens" in a zone of faults and dykes where the lens was otherwise expected, suggesting the lode has been structurally displaced or "pinched out" in this location. The Mostaza Cu-Ag deposit, Cerro Negro: The high-grade Cu-Ag mineralisation at Mostaza is confined to a north-south trending, structurally-controlled lode, or "lens" (specifically Lens 2), of variable width (<4-20m) that dips moderately steeply to the west. Copper mineralisation comprises abundant disseminations, veinlets, crackle networks, and breccia matrix fillings of hypogene black to dark metallic grey chalcocite with lesser bluish bornite and traces of chalcopyrite and pyrite. Petrographic confirmation is pending, however, the copper mineralogy may include other silver-rich copper minerals such as stromeyerite (AgCuS) for example. Lens 2 host rocks are intensely altered and appear to comprise multiple generations of breccia, tuffisite, and felsic intrusive altered to texturally destructive illite ± montmorillonite overprinted by probable alunite ± dickite ± pyrophyllite (to be confirmed by petrographic studies). The high-grade Cu-Ag mineralised lens exhibits sharp contacts and is bounded to the east and west by faults that are typically invaded by narrow (<1-2m) andesite to rhyolite dykes. Outside of the bounding dykes and faults, the enclosing wall rocks consist of an east-dipping bedded sequence of fresh, black volcanic lava flows and red, hematite-rich phreatic and/or phreatomagmatic breccias that might be part of a large dome-diatreme complex outcropping to the east. Insufficient drilling is available to date to allow detailed interpretation of the architecture of the deposit. The lack of high-grade mineralisation intersected in hole DD004 indicates late-stage structural dislocation occurs resulting in variable localised thinning or boudenaging of the lenses. Broad zones of weakly anomalous silver (>0.1ppm Ag) in hole DD004 might also suggests the potential for this hole to be adjacent to significant lode mineralisation. The narrower lode width intersected in hole DD002 suggests also that mineralisation may be "stoped out" in places by post-mineral dykes of the same type that intrude the bounding fault structures. The high-grade Cu-Ag mineralogy type and associated advanced argillic style alteration suggests the lodes at Mostaza are part of a high-sulphidation epithermal system, potentially related to a yet-to-be-discovered porphyry style deposit occurring at depth. The Lens 2 mineralisation is interpreted to form one of a number of Cu-Ag rich bodies mapped at surface which have historically been interpreted as discrete "lenses" but which collectively have the potential to make up an anastomosing network of structurally controlled zones of mineralisation continuous over a strike length of greater than 1-2km. The results of CNG25 DD001- DD005 targeting mineralisation beneath the existing Mostaza open pit demonstrate that the deposit continues at depth and along strike from the historical drilling and is open in all directions.