Norwest’s maiden drill program at the Bali project in Western Australia has identified broad intervals of copper mineralisation at all four tested targets.
Handheld portable XRF readings returned results such 57m grading 1.3% copper from surface (BRC001), 33m at 0.7% copper from a down-hole depth of 23m (BRC022), 27m at 0.7% copper from 6m and 2m at 3.4% copper from 38m (BRC025) and 20m at 0.6% copper from 2m (BRC018).
While no replacement for laboratory assaying, the pXRF readings are a strong indicator that copper mineralisation is present across each of the Bali Lo, Bali East and Bali South prospects.
Adding further interest for Norwest Minerals (ASX:NWM), the pXRF analyser detected intervals of copper, lead and zinc at the Bali High prospect with a top hit of 5m at 1% copper, 5.3% lead and 3.4% zinc from 35m in BRC016.
This is a positive initial result for the 33 hole reverse circulation drill program totalling 3,900m – the first drilling carried out at the Bali project in Western Australia’s Pilbara region since 1989.
Separately, mapping and rock chip sampling at the Deep South area has identified two additional vein structures with pXRF returning copper readings of 44%, 34% and 16% from V6 rock chips and 56% at a V7 rock chip.
“The new program successfully tested each of the four prospects by drilling a series of holes along the strike of the mineralised Bali shear with the aim of locating the source(s) for the high-grade copper exposed at surface,” chief executive officer Charles Schaus said.
“All prospects returned wide zones of copper mineralisation from pXRF measurements of the 1m RC drill samples.”
To improve the company’s understanding of the composition, orientation, and extent of the mineralisation, Schaus added that the company had prepared five of the holes across all four prospects for downhole geophysical measurements in early November.
Bali copper project and drilling
The Bali project comprises about 8km of the Bali shear zone; a major structure extending through the region and hosting numerous copper and other base metal prospects.
RC drilling targeted the four high priority prospects where historical drilling and rock chip samples had returned significant copper results.
According to first pass analysis using pXRF, many holes returned wide intercepts with more than 0.2% copper with 10 individual metres reading more than 0.3% copper.
Bali Lo hosts the top copper intercept though Norwest noted that hole BRC001 was drilled down the dip of the mineralised structure and that further information might be gleaned from downhole geophysics to be undertaken on hole BRC004.
Meanwhile, Bali Hi contains the only lead and zinc results while Bali East recorded the widest intersections and appears to be open along the Bali Shear to the southeast towards the tenement’s western boundary.
While all these results are encouraging, the result from Bali South might be the most significant given that it is not located on the Bali Shear but rather on what appears to be a parallel structure to the southwest similar to the narrow structures being mapped and rock chip sampled at Deep South.
Drillhole BRC025 at Bali South also returned the highest grade-by-width intersection to date – excluding BRC001.
Casing has been put in holes BRC004, BRC016, BRC018, BRC022, and BRC025 for downhole geophysical analysis scheduled for early November.
This will provide a better understanding of the orientation of the mineralisation and assist in future drill targeting.
Geophysical and drill hole planning to test the depth extensions of the new high-grade Deep South is now underway.
This will seek to use geophysical techniques to determine if the Deep South structures extend further along strike below the ground cover, extend down dip, and to identify further copper-gold veins from geophysical signatures produced by V1 to V7.
This article was developed in collaboration with Norwest Minerals, a Stockhead advertiser at the time of publishing.