North Dovers was identified by BHP in 1999 as the area’s primary IOCG target but due to strict access regulations at the time no exploration drilling was completed. The commencement of diamond drilling in May 2019 has established Norwest as the first company to drill into this very large IOCG target since its identification 20 years ago.
Norwest completed a 3-hole diamond drilling program at the North Dovers prospect where it successfully intersected thick sequences of favourable IOCG geology and alteration plus minor occurrences of chalcopyrite (primary copper mineralization), pyrite (iron sulphide) and sphalerite (primary zinc mineralization).
The Company established that the Proterozoic basement at North Dovers occurs relatively close to surface thus allowing future exploration drilling for an IOCG system to be conducted using cost effective reverse circulation (RC) rigs. Norwest commenced an extensive RC drill programme in September 2019 designed to test the majority of the 4 x 8-kilometre long North Dovers anomaly.
Based on the encouraging results from the diamond drilling programme at North Dovers (discussed below), Norwest increased its ground position with the acquisition of a 250km² tenement strategically located immediately south of the North Dovers anomaly increasing the Company’s total Arunta West ground holding to 1,700km².
Diamond Drilling of the North Dovers IOGC Anomaly
At Arunta West, three diamond holes totalling 1,524 metres were drilled into the North Dovers IOCG target. The HQ and NQ drill core shows encouraging signs of IOCG potential including hematite altered granite located adjacent to highly magnetic diorite units plus minor amounts of chalcopyrite (primary copper mineralisation), sphalerite (primary zinc mineralisation), and pyrite (iron sulphide).
The Proterozoic basement was encountered near surface with holes NDD1901 and NDD1902 collared into a unit of magnetic diorite prior to intersecting hematite altered granites up to 80 metres wide and ending in a syenogranite. Early structural data indicates the units dip moderately to steeply south.
Two main sedimentary sub-units were also encountered including: 1) a graphitic shale (NDD1902) with abundant pyrite and minor chalcopyrite and 2) a quartzite (metasandstone/siltstone) interbedded with patchy hematite alteration.
Half of the core was delivered to the Department of Mines, Industry Regulation and Safety as per the State Government’s Exploration Incentive Scheme. The Department contributed $150,000 toward the North Dovers diamond drilling. The half-core retained by Norwest was cut again with ¼ core sent in for multi-element assaying and the other ¼ core held for reference by the Company.
The Arunta West project is a joint venture with Jervois Mining Limited (ASX:JRV 49%) (ASX:NWM 51%-manager, earning 80%), and takes in three tenements covering 345 km² of the prospective Lake Mackay district of Western Australia. Norwest also holds 100% interest in two tenements adjoining the Arunta West JV area covering an additional 1,100 square kilometres. Norwest has recently acquired 85% of a 250km² tenement located immediately south of the North Dovers anomaly as displayed in figure 5 above.