Infinity Mining will kick off a maiden 1700m RC drilling program at its Brisbane nickel-chromium prospect in Western Australia’s Pilbara region early next month.
The company has released plans to drill 10 holes across its ultramafic basal contact target where previous rock chips returned up to 0.764 per cent nickel and 0.892 per cent chromium. It will also probe an area 350m further east where a helicopter electromagnetic survey returned a 700m-by-400m prominent conductive target that may represent nickel sulphides.
Infinity received cultural heritage clearance from the Nyamal Aboriginal Corporation earlier this week after survey work by service provider Heritage WA alongside members of the Nyamal Native Title Group. The company also received $117,810 in WA Government grant funding for the work. Access track and drill pad preparation is in progress to help facilitate the early June drilling start.
Reconnaissance exploration work at the Brisbane prospect last year confirmed the presence of a big, magnesium-rich ultra-mafic peridotite body with gossanous and silicified shear zones, plus gossanous cherts along the peridotite contact. Strong iron and manganese rich gossans were seen and rock-chip samples assayed up to 0.764 per cent nickel, 0.892 per cent chromium and 0.257 per cent zinc. Six RC drill holes will now test along the strike of the Brisbane prospect.
In October last year, Infinity conducted its helicopter electromagnetic survey with 449 line kilometres covering the area around its Brisbane prospect. Management concluded that a coincident public domain magnetic anomaly identified could be related to alteration and mineralisation.
The anomaly has been scheduled for four RC drill holes in the current program with evenly-spaced holes planned and different dip directions accounted for by drill orientations. The relationship between the anomaly and the Brisbane prospect is not yet known.
Infinity says preliminary results from its survey are being processed and are providing promising new targets for it to follow up this year.
The Brisbane prospect was discovered by in 1969 by Planet Metals, which carried out a program of geological mapping and rock-chip sampling along the basal contact of a magnesium-rich ultra-mafic intrusive of the Dalton Suite. Planet returned rock chip samples of up to 0.52 per cent nickel and 1.48 per cent chromium in iron oxide rich shears in a strata-bound basal olivine-rich peridotite intrusive.
Planet did not assay for platinum group metals, although the geological setting appears favourable. No further work was conducted at the Brisbane nickel-chromium prospect until Infinity started its exploration last year.
The target ultramafic unit at Brisbane has intruded the contact between mafic rocks to the south-west and felsic volcanics to the north-east. The rocks are strongly folded and lie on the southern limb of a big south-west-plunging anticline structure and the area is heavily-faulted. Government magnetic data available to the public indicates that the prospective ultramafic intrusive of the Dalton Suite continues underneath the mapped Fortescue Group to the south.
Infinity Mining chief executive officer Joe Groot said: “Infinity’s team has been in the East Pilbara since late February this year. Whilst undertaking this field work, we have also completed the road access, site preparation and remote camp infrastructure set-up necessary to allow drilling to commence on time. “
The company has completed an ambient nosie tomography survey at its Tambourah South pegmatite lithium tenement, which is also in the Pilbara. The technique uses low-impact seismic survey to investigate structures in the earth’s crust that may host or be related to mineralisation.
The survey will generate 3D seismic images down to 200m and has been designed to locate and image the pegmatite zones and geology below the surface. Management will use the resulting data to interpret a 3D geology model of the lithium-bearing pegmatite systems at Tambourah South and also to aid drill targeting.
With two intriguing nickel targets at Brisbane, Infinity’s maiden drill program could turn up some interesting rocks. It will be hoping for chromium-rich nickel sulphides along the prospective ultramafic basal contact zone where so many WA sulphide nickel deposits are found.
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By Terry Bates
