Marimaca Copper Corp. has announced the results of the five drill hole diamond drilling exploration programme from the eastern margin of the Marimaca oxide deposit (MOD). The programme was designed to follow-up on the sulfide-bearing intersection of the previously released hole MAD-22, which intersected higher grades of primary copper mineralisation down-dip of the Marimaca oxides. The programme 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 programme 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 m 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 localised faulting.
- Holes MAD-24, 25, 26 and 27 intersected the extension of the upper oxide and mixed/enriched copper mineralisation.
- This zone is interpreted as the near-surface, oxidised expressions of high-grade mineralised structures encountered in MAD-22.
- MAD-25 intersected 56 m at 0.4% CuT from 136 m including 24 m at 0.63% CuT of secondary and primary sulfides 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 m.
- Hole MAD-24 intersected 74 m of 0.52% CuT from 24 m including 18 m at 0.68% CuT from 24 m and 28 m at 0.79% CuT from 64 m above the projected sulfide horizon.
- Hole MAD-24 intersected a barren post-mineral dyke from 224.3 m which occupied the projected extension of the sulfide horizon from MAD-22.
- Hole MAD-27 intersected 40 m at 0.5% CuT from 68 m including 18 m at 0.9% CuT of mixed and enriched mineralisation from 74 m, and a deeper intersection of 12 m at 1% CuT of chalcopyrite mineralisation from 162 m.
- Hole MAD-26 intersected strong magnetite alteration from 186 m, 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, VP Exploration of Marimaca Copper, 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 programme, which is the first time that consistent sulfide-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 mineralisation 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 sulfide potential warrants this. We continue to believe that the sulfide potential is high, particularly considering the scale of the oxidised mineralised 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.”