Great Southern Copper (LSE:GSCU) reported final Phase III drill results from the Mostaza Cu‑Ag discovery at the Cerro Negro prospect that include a narrow high‑grade intercept of 0.5m @ 4.24% Cu and 233 g/t and confirm continuity of mineralisation down‑dip and along strike.
The Phase III programme, completed in January 2026 and comprising 17 diamond holes for 2,923m and six scout RC holes for 1,032m, returned multiple significant intervals including 17m @ 0.69% Cu and 48.21 g/t (DD045), 3.4m @ 1.44% Cu and 103.8 g/t (within DD045) and 2m @ 2.0% Cu and 123.7 g/t (DD046), with Great Southern Copper, a UK‑listed explorer focused on copper‑gold‑silver in Chile, also confirming a hanging‑wall Pb‑Zn‑Ag breccia and stacked lens morphology that extends the known footprint along the 2km Mostaza Fault Zone.
"The predictability of the deposit is improving, providing a clear focus for the next phase of drilling, with the system remaining open along strike and at depth," Sam Garrett, Chief Executive Officer, said.
All Phase III assays have now been received, metallurgical test work is underway, and Phase IV planning is in progress to deliver infill and step‑out drilling to expand the Mostaza resource across the Cerro Negro system where GSC holds rights to 100% of the prospect.
