Visible Copper Extends IOCG Mineralisation Over 700m at Three Saints, Chile

Second Drill Hole Confirms Scale of IOCG System

Lodestar Minerals (ASX:LSR) has delivered a significant update from its Three Saints IOCG Project in Chile, confirming visible copper and iron oxide copper gold (IOCG)-style mineralisation in its second diamond drill hole (L3SDD004). The drill hole, currently in progress, has intersected multiple mineralised intervals featuring native copper, chalcopyrite, pyrrhotite, magnetite, and pyrite from 219 metres down to 510 metres. This extends the known mineralised system over a 700-metre strike length when combined with the maiden hole (L3SRD003), suggesting a potentially large IOCG system beneath the Atacama sands.

The presence of pervasive actinolite alteration alongside disseminated sulphides marks a step up in alteration intensity compared to the initial drill hole, with mineralisation appearing at shallower depths. The second hole was drilled from the northern edge of a 1-kilometre diameter annular magnetic "negative" anomaly towards its centre, complementing the maiden hole drilled from the southern edge. This geophysical anomaly is interpreted as a demagnetisation zone caused by hydrothermal alteration destroying original magnetite, a hallmark of IOCG systems.

Hydrothermal Alteration and Mineralisation Details

Geological logging of the diamond core reveals a complex assemblage of sulphides and magnetite associated with hydrothermal breccias, veins, and pervasive alteration. Notably, native copper was observed disseminated in tonalite from 219 to 230 metres, quickly transitioning into sulphide-dominated mineralisation with increasing magnetite content below 300 metres. The sulphide suite includes pyrite, pyrrhotite, chalcopyrite, and molybdenite, with sulphide abundance increasing with depth. The alteration assemblage progresses from chlorite-dominated zones to actinolite-magnetite assemblages indicative of proximity to the system core.

These observations align with IOCG-style mineralisation seen in the region, including at the nearby Candelaria Mine, Lundin Mining’s largest operation located about 65 kilometres away. However, Lodestar cautions that visual mineral estimates are qualitative and assay results are required to quantify copper grades and economic potential. Assays from the maiden hole are expected by the end of May, with results from L3SDD004 anticipated in early July.

Strategic Location and Next Steps

The Three Saints Project lies in Chile’s Coastal Cordillera, an area with established mining infrastructure, situated 35 kilometres from the Pacific coast and 20 kilometres from a major highway. The project is fully undercover beneath Atacama sands, making geophysical targeting critical. The ongoing drilling campaign aims to delineate the extent of the mineralised system, with the current hole planned to reach 600 metres depth and potential extensions considered based on geological observations.

Lodestar’s CEO Coraline Blaud highlighted the significance of reproducing mineralisation over such a large strike length, stating this supports the interpretation of being on the margin of a substantial IOCG system. The company is systematically logging and photographing core for detailed analysis and sampling at La Serena, Chile.

This update follows the company’s earlier visible copper sulphides in maiden hole announcement, which first identified IOCG-style mineralisation at Three Saints. It also builds on the exploration momentum under new CEO Coraline Blaud, who was recently elevated amid expanding projects across continents Lodestar Elevates Coraline Blaud to CEO.