Marimaca Copper drills 0.52% CuT over 74 metres at Marimaca, Chile
Marimaca Copper Corp. [MARI-TSX] reported results of the five-drill-hole diamond drilling exploration program from the eastern margin of the Marimaca oxide deposit (MOD), Antofagasta Region, Chile. The program was designed to follow up on the sulphide-bearing intersection of the previously released hole MAD-22, which intersected higher grades of primary copper mineralization down dip of the Marimaca oxides.
The program encountered challenging drilling conditions due to the orientation of the drilling from existing drill pads along major known structures at the MOD. Results from this program and learnings regarding the approach for potential future deeper drilling, particularly origin and orientation, and will be considered for the design of follow-up exploration work.
Highlights: Four drill holes recovered to a maximum depth of 349 metres from surface, with three holes completed successfully to target depth.
The fourth hole, although recovered, MAD-25 was terminated above target depth due to poor rock quality caused by localized faulting.
Holes MAD-24, 25, 26 and 27 intersected the extension of the upper oxide and mixed/enriched copper mineralization. This zone is interpreted as the near-surface, oxidized expressions of high-grade mineralized structures encountered in MAD-22.
MAD-25 intersected 56 metres at 0.40% total copper (CuT) from 136 metres, including 24 metres at 0.63% CuT of secondary and primary sulphides in line with the projected horizon from MAD-22, however, could not progress further into the horizon due to rock quality in a fault zone and was terminated at 218 metres.
Hole MAD-24 intersected 74 metres of 0.52% CuT from 24 metres, including 18 metres at 0.68% CuT from 24 metres and 28 metres at 0.79% CuT from 64 metres above the projected sulphide horizon.
Hole MAD-24 intersected a barren post-mineral dike from 224.3 m which occupied the projected extension of the sulphide horizon from MAD-22.
Hole MAD-27 intersected 40 metres at 0.50% CuT from 68 metres, including 18 metres at 0.90% CuT of mixed and enriched mineralization from 74 metres, and a deeper intersection of 12 metres at 1.0% CuT of chalcopyrite mineralization from 162 metres.
Hole MAD-26 intersected strong magnetite alteration from 186 metres; however, with a higher pyrite/chalcopyrite ratio relative to MAD-22 corresponding to lower grade copper intersections.
MAD-23 was terminated as a result of contractor operational performance leading to contractor replacement for subsequent holes (MAD-24, 25, 26, 27).
Sergio Rivera, vice-president of exploration, commented: “Despite challenging drilling conditions we continue to improve our understanding of Marimaca’s genesis and target generation for the potential sulphide feeder zones. We are very encouraged to see the continuation of the alteration assemblages and rock types observed in MAD-22 in the follow-up program, which is the first time that consistent sulphide-associated alteration has been observed below the MOD. MAD-25, in particular, which stepped out 500 m to the south of MAD-22, intersected the expected alteration mineral assemblages with strong mineralization at the targeted horizon, but was terminated before the expected higher-grade zone due to the intersection of a fault zone, which deviated the hole.
“Planning for the next phase of sulphide exploration will incorporate learnings from this first phase campaign, including adjusting the approach to drilling from east to west to allow for easier orientation of the drilling to the deeper target horizons. Approaching from the west will take time to plan new drilling infrastructure rather than using existing eastern drill pads at the MOD; however we believe the sulphide potential warrants this.
“We continue to believe that the sulphide potential is high, particularly considering the scale of the oxidized mineralized body at the MOD and the indications, such as hole MAD-22, that higher grade remnant feeder structures, remain intact in the shallower down-dip zones of the MOD.”