Estrella Resources’ aggressive approach to revitalising the old Carr Boyd nickel mine north of Kalgoorlie in Western Australia has generated positive leads from two new diamond drill holes. The company says results from the two holes in its ongoing drilling of the T5 nickel-copper discovery adjacent to the former mine include a 13.75m intersection of massive and globular nickel-copper-iron sulphides on the T5 basal contact.
The other hole, targeting an area about 30m south of the first one, hit 6.4m of mineralised matrix breccia, globular and disseminated sulphides.
Estrella said the phase-three drilling program was continuing on the T5 discovery with some step-out drilling of the T5 conductor plates.
The company said the drill-hole that intercepted the 13.75m of mixed sulphides, CBDD050, targeted a zone towards the middle of the T5 conductor and was up-dip from an earlier hole that hit a 22.85m section of mineralised massive, globular and disseminated nickel-copper sulphides on the T5 basal contact.
Estrella said the latest hole hit mineralisation totalling about 44.7m downhole with the 13.75m of massive to globular sulphides at the base of the hole.
It said the upper area showed predominantly disseminated sulphides for more than 28m down to 383.8m vertical depth. According to the company, this showed evidence of a sulphide setting from a siliceous plume believed to carry the majority of sulphides through the feeder to the T5 trap site.
The second of the new holes, CBDD050, intersected two heavily sulphidic zones separated by a small mafic dyke and disseminated pyroxenite. These sulphides are seen as being carried towards the CBDD055 area and contribute to the upper, fine-grained sulphide halo as well as globular sulphides atop the silica plume.
Estrella said the sulphide textures observed in the current drilling confirmed the settling, remobilisation and re-settling of massive sulphides along the T5 Pyroxenite Feeder basal contact. The company believes latest drilling shows the entire T5 Pyroxenite surface “is in the correct orientation to be a sulphide trap, with respect to the flow direction and resulting flow dynamics”.
The technical report attached to Estrella’s latest announcement said a handheld XRF tool was used to verify the mineralisation, with samples reporting more than 0.3 per cent nickel in disseminated zones and more than 1 per cent nickel in matrix sulphide zones. The results have not been reported and are said to be used as a logging-sampling verification tool only.
Estrella Resources Managing Director Chris Daws said: “Our success at hitting significant zones of nickel-copper-iron sulphides continue at Carr Boyd, and it is extremely pleasing to see that our exploration efforts are being rewarded at the drill-bit.”
“The understanding of Carr Boyd has greatly improved since our deep drilling program kicked off late last year and I am confident we will continue to locate metal sulphides within this very prospective system.”
Mr Daws said Estrella was in its strongest position ever since acquiring Carr Boyd after the successful $11.3 million underwriting of the company’s June options and exercising by its shareholders.
The company said the geological model being applied at Carr Boyd had been recognised in exploration for other significant world-class deposits around the globe.
Current phase-three drilling will continue to step-out along the T5 conductor to gain important vectoring information to further areas of suggested massive sulphide deposition beyond the current T5 electromagnetic conductor.
The Carr Boyd nickel-copper mine was originally developed in the 1970s nickel boom by Kalgoorlie gold miner Great Boulder but after a major slump in the nickel price it was taken over by Western Mining Corporation which saw production of about 200,000 tonnes of ore grading 1.43 per cent nickel and 0.46 per cent copper.
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By Matt Birney
