The company also announces results from five broad reconnaissance exploration holes, which were designed to identify the limits of the mineralised horizon. This drilling, when combined with the full review and relogging of historical drilling, shows consistent broad zones of oxide copper mineralisation of variable grades in the same stratigraphic horizon over an area of approximately 5 km by 4 km, which is the current defined extent of the manto horizon. Potential exists for further extensions in all directions, with ongoing step out programmes.
Based on the extensive work completed, including the new drilling results extending Pampa Medina, the company believes that Pampa Medina may be the central part of a larger manto system, which genetically links the Madrugador, Pampa Medina, Sierra Valenzuela (Antofagasta Minerals) and Pampa Norte deposits. It was this interpretation which led to the discovery of the new, shallow oxide opportunity at Pampa West. Based on these results, the company will continue with its strategy of large-scale step-out holes from known mineralisation, and deep sulphide-target drilling to try to identify the limits of the system.
Marimaca is considering alternatives for a significantly expanded programme for the balance of 2025 to include both reverse circulation (RC) and diamond drilling. The objectives of this programme will be to continue to step out to identify the limits of the system, to test the deeper units for primary copper mineralisation and to delineate areas for potential extensions of near-surface oxide mineralisation.
Sergio Rivera, VP Exploration, commented:
“Our extensive reviews of existing data, our geophysical campaigns, and the results from our initial step out discovery campaign indicate Pampa Medina is likely to be part of a much larger manto system, which extends at least 5 km east to west and more than 4 km north and south. As with all large-scale mineralising systems, there is zonation and variability of grade, but we are excited about both the continuity of mineralisation in the productive sedimentary and tuff horizons and the large-scale mineralising events which have impacted them across this area.
“The significant east-west step outs at Pampa Norte, either side of the fantastic drill hole at SMR-01, encountered offset faulting and a series of barren dykes, which are important controls of mineralisation. However, we can now clearly see the potential for 1000 m of east-west extent of the mineralised envelope for Pampa Medina, which becomes important for resource growth potential in future programmes.
“Our exploration model, which hypothesised that the majority of the historical drilling was not deep enough to targeting the productive sedimentary units, has been confirmed and we see numerous opportunities for further discovery and extension from our existing deposits.”
Hayden Locke, President and CEO, commented:
“With the Pampa Norte Extension we see a strong potential for additional leachable mineralisation in the short term, and we will move to a de-lineation programme later this year. In the longer term, the potential for a large-scale discovery is very much intact and we intend to test our exploration model thoroughly.
“This is the first time that the Pampa Medina system has been largely consolidated under one operator, and as such the first time that all available geological information has been consolidated and reviewed as one. While previous interpretations considered each of our identified zones as separate and distinct deposits, we are excited about the potential for Pampa Medina to rather represent a single, large-scale mineralised system.”