Great Southern Copper PLC (LSE:GSCU, FRA:E9E) this week reported further high-grade copper results from drilling at the Mostaza discovery within the Cerro Negro project in Chile, as the company continues to expand the scale of the mineralised system.
In an interview with Proactive, chief executive Sam Garrett said the latest drill hole returned grades of up to 6.55% copper alongside strong silver values, describing it as another “very good drill hole” for the company.
Garrett explained that the intersection is particularly significant because it represents a step-out roughly 400 metres south of earlier drilling, confirming that mineralisation continues along the Mostaza fault trend beyond the historic Mostaza pit.
He said the results reinforce the company’s geological interpretation, noting that the same style of mineralisation seen in earlier holes is also present in the latest drilling.
Garrett told Proactive that the results demonstrate consistent geological architecture between the new hole and previous drilling beneath the Mostaza pit, increasing confidence that separate mineralised zones could eventually be linked.
Proactive: Sam, very good to speak with you. This latest drill hole hits up to 6.55% copper and also strong silver grades. How significant is this result for the Mostaza discovery?
Sam Garrett: Good morning Stephen and good morning everyone. This is another very good drill hole for the company. It is significant in that it confirms the step-out about 400 metres to the south of recent drilling and results in holes 33 and 36. It confirms that the company is still seeing the same style of mineralisation along the Mostaza fault trend that has been drilled beneath the Mostaza pit. So it is very significant.
Proactive: The hole was drilled 300 metres from the historic mine and is still hitting mineralisation. What does that tell you about the scale of the system?
Garrett: It tells us that the company is on the right track to increasing the scale of the system. The next step is to infill between that zone and the mine and also drill beyond it. What is critical is that the zonation of mineralisation seen in hole seven and hole 42 is consistent with the zonation seen in the Mostaza pit.
That suggests the architecture is the same, which increases confidence that the company can link the two zones together and hopefully extend the mineralisation further south. The grades remain very high and there are also broad zones of lower grade material up to around 20 metres thick. Overall the results indicate the exploration program is progressing in the right direction.
Proactive: You’re seeing copper, silver, lead and zinc in stacked zones. How does that change your understanding of the geology at Cerro Negro?
Garrett: This hole confirms the geological architecture previously reported in holes 33 and 36 drilled beneath the Mostaza pit. Every hole provides new information. When the company saw the strong lead and zinc values it reviewed earlier drilling, including hole seven, and confirmed those anomalies were present there as well.
This is encouraging because it suggests a consistent system, although it has been structurally disrupted by faulting and diking. The key point is that the company is seeing the same geological architecture in new holes drilled about 300 metres south of the Mostaza pit, and mineralisation now extends over about 400 metres of strike.
Proactive: What are the key goals for the fully funded Phase 4 drilling program?
Garrett: The company will continue drilling mineralisation further south where it extends beneath shallow cover. If that proves successful it becomes very exciting because it suggests the system could extend much further.
The company will also carry out infill drilling between hole 42, hole seven and the Mostaza pit. Ideally the company could demonstrate mineralisation over a 400 to 600 metre trend or potentially longer, connecting towards mineralisation already identified at surface across a two kilometre trend. At this stage the results suggest the exploration program is heading in the right direction.
Proactive: Sam, I hope you’ll continue to keep us updated with your progress. Thank you very much for your time.