Great Southern Copper plc (LON: GSCU) has reported a significant new porphyry copper discovery at its Especularita project in Chile, with scout drilling intersecting 106 metres at 0.33% copper and 42ppm molybdenum from surface.
The standout result came from hole RC009 at the Artemisa North prospect and included 54 metres at 0.46% copper and 66ppm molybdenum from 16 metres, with a higher-grade section of 20 metres grading 0.57% copper and 116ppm molybdenum.
Great Southern said the disseminated and vein-hosted chalcopyrite, bornite and molybdenite mineralisation occurs within potassic alteration and is strongly indicative of a porphyry copper system. Importantly, mineralisation remains open in all directions, with RC009 ending in chalcopyrite-mineralised granodiorite.
The discovery follows a proof-of-concept reverse circulation drilling programme designed to test several targets surrounding the extensive La Colorada lithocap. A total of 17 holes covering 2,474 metres were completed across Artemisa North, Artemisa South, Victoria and Piedras Blancas.
Results have so far been received for only four holes, leaving assays from 13 additional holes pending.
At the Victoria prospect, hole RC011 also encountered broad potassic alteration and copper-gold mineralisation, including 14 metres at 0.23% copper and 0.18g/t gold from six metres, with a two-metre section grading 0.85% copper and 0.48g/t gold.
The geological similarities between Victoria and Artemisa North support Great Southern’s interpretation that a broader porphyry system could exist around the margins of the La Colorada lithocap.
Chief executive Sam Garrett said the RC009 result had exceeded expectations and validated the company’s strategy of using relatively inexpensive scout drilling to test targets before committing to larger exploration programmes.
The company will now undertake detailed mapping and sampling around Artemisa North ahead of potential IP geophysical surveys and follow-up RC drilling, while awaiting results from the remaining scout holes.
Great Southern holds rights to acquire 100% of Especularita, which is located at relatively low elevation in Chile’s coastal metallogenic belt with access to established mining infrastructure. The project lies along trend from major copper deposits including Los Pelambres, Altar and El Pachon.
