Native Mineral Resources Holdings Limited (ASX: NMR) has announced excellent initial results from the Phase 1 reverse circulation and diamond drilling program at its Leane’s Copper Prospect in North Queensland.
The company said that six drillholes out of the planned 15 drillholes have been completed to date, of the Phase 1 program that is planned to be completed by mid-December.
NMR said that the RC drilling had commenced to locate deeper intrusive-related mineralisation and the first hole intersected porphyry veins at a depth of 90m. The company said that this will be extended by diamond coring to provide detailed geological information at depth testing for the presence of a larger intrusive system below the skarnbreccia zone.
Native Mineral said that five drillholes testing for shallow skarn-style mineralisation has intersected near-surface iron-rich breccia with elevated copper, as measured using a portable XRF instrument.
The company said that the assays from the first three holes are pending and expected to be received in mid-December.
NMR said that the planning is well advanced to commence exploration elsewhere at Palmerville Project and the Eastern Goldfields Project in early 2021.
NMR holds a large portfolio of advanced exploration tenements in Queensland (Palmerville Project and Mount Morgan Project) and Western Australia (Eastern Goldfields Project).
The Palmerville Project is the Company’s principal exploration asset and covers a near continuous strike length of 130km over an area of ~1,820km2 centered 200km west-northwest of Cairns in North Queensland.
NMR has completed a review of historical mining activity and past exploration and identified 65 mineralisation occurrences and eleven initial targets for exploration.
The Leane’s Copper Prospect is in the central area of the Palmerville Project and was originally discovered in 2007 by Lodestone Exploration Limited when outcrops containing malachite veining were mapped at surface.
Subsequent exploration, including detailed soil geochemistry identified strongly anomalous copper over a 1,200m extent along a north-northwest trending brecciated contact between limestone to the west and siliciclastic sediments, and locally basalt to the east.
Leane’s prospect is characterised by a +500 ppm Cu-in-soils anomaly that extends for about 1 km along a north-northwest trending brecciated contact between limestone to the west and siliciclastic sediments, and locally basalt to the east.
NMR considers that Leane’s is analogous to the Red Dome and Mungana deposits some 100km to the south, where gold and base metal-bearing intrusive magmatic porphyry bodies were partially overprinted and modified by late-stage breccias formed by degassing and explosive release of over-pressured fluid.
RC drill program in 2010
In 2010, Lodestone completed a shallow 8 drillhole RC program to test the copper soil anomalies over a 500 m strike length, plus two drillholes further south to test gold anomalies. The best intervals in that program intersected 28m @ 0.55% Cu in drillhole LRC004, 4m @ 0.55% Cu in drillhole LRC003, and 11m @ 0.32% Cu in drillhole LRC002.
All drilling intersected the breccia zone in the weathered horizon. No further exploration was undertaken at Leane’s since 2010.
Drilling at Leane
The company had commenced a 2,000m RC/diamond drilling program to follow up and extend the shallow drilling completed at the Leane Prospect in 2010.
NMR said that this program aims to infill gaps in the previous program and test the shallow skarn/breccia copper zone (Phase 1) as well as target the interpreted deeper porphyry-related copper-gold mineralisation.
Status of 2020 Phase 1 drilling program
NMR reported that the drilling at the Leane’s Prospect commenced in mid-November. The company said that five shallow drillholes, LRC011, LRC012, LRC013, LRC014, and LRC015, have been completed to date.
Encouraging drill results
NMR said that every hole intersected near-surface skarn-style breccia with elevated copper, as measured using a portable XRF instrument.
Porphyry veins intersected
The company announced that the first drillhole (LRC015) to test for deeper intrusive-related mineralisation intersected porphyry veins at 90m depth and will be extended by diamond coring to provide detailed geological information at depth testing for the presence of a larger intrusive system below the skarnbreccia zone.
Presence of a larger intrusive system
NMR said that the drilling has successfully demonstrated that the proposed exploration and mineralisation model for Leane’s is valid, confirming the geological interpretation and the presence of the skarn/hydrothermal breccia at the contact of sediments and limestone in the Chillagoe Formation.
NMR said that the samples from the first three holes have been dispatched for analysis and results are expected to be received in mid-December.
The company said that the planning is well advanced to commence exploration elsewhere at Palmerville Project and the Eastern Goldfields Project in early 2021.
NMR’s Managing Director, Blake Cannavo, commented: “These are truly impressive indications from our initial drilling program at Palmerville and it is certainly an exciting time for NMR. Our first five holes have intersected shallow skarn-style breccia with elevated copper grades based on portable XRF measurements, which is a strong validation of the exploration strategy we have implemented, also demonstrating that our exploration and mineralisation model for Leane’s is spot on.
Every hole completed so far has intersected shallow skarn-style breccia with elevated copper grades and our first deeper hole has intersected porphyry veins suggesting the presence of a larger intrusive system below the skarn-breccia zone.
Following these encouraging early results from shallow drilling, our field crew is now ready to commence a diamond drillhole to test mineralisation at depth as the current drillhole has intersected porphyry veins suggesting the presence of a larger intrusive system below the skarn-breccia zone.
The first tranche of samples has been dispatched for analysis and we look forward to receiving the results in December. In parallel, we are also planning our 2021 exploration programs for both the Palmerville and Eastern Goldfields Projects and look forward to testing several other priority targets over the coming months.”