Impact Minerals’ maiden drilling program over its Little Broken Hill Gabbro nickel and platinum group element project has validated the company’s conceptual modelling, with three first-pass nickel-PGE targets confirmed in the north of the 6-kilometre-long mafic intrusion. Exploration shows the PGE mineralisation increasing in both thickness and grade with depth, with better results including 51 metres at 0.3 grams per tonne 3PGE from 140m.
Another notable result was 11m at 0.8 g/t 3PGE from 101m down-hole, with both holes also exhibiting anomalous copper mineralisation.
The three key targets identified for detailed follow-up are Rockwell, Western Contact and the Central LBHG target, all of which are in the northern half of the Little Broken Hill Gabbroic intrusion. Whilst the three targets extend across several kilometres of strike, the Little Broken Hill Gabbro intrusion is more than 6km long and up to a kilometre wide, representing a significant geological target for ongoing exploration.
Impact Minerals Managing Director, Dr Mike Jones said:“These results continue to confirm our belief that the LBHG may potentially contain a vast reservoir of PGE’s and possibly nickel and copper. We have to remember that this is the first ever drill programme to test the basal ultramafic unit and yet every drill hole that has intersected it has returned some level of mineralisation. It is evident that there is very significant potential along the entire length of the 6.5 kilometre long intrusion.”
“We have made another breakthrough with our ratio indicating two separate chemical trends are at play and this will further help guide our follow up drill programmes. We are fortunate that most of the immediate follow up drill holes already have statutory approvals in place and we look forward to drilling at Broken Hill as soon as possible after our on-going drill programme at Apsley is complete”.
The company’s Little Broken Hill Gabbro discovery is located around 18km south, south-east of the famed Broken Hill mining centre in western NSW. The discovery forms part of Impact’s comprehensive tenement package south of the revered mining town extends along 75km of strike and covers more than 800 square kilometres of the mineral-rich Curnamona Province.
Impact has already enjoyed considerable success at Broken Hill, having identified a swag of prospective targets ranging from the Copper Flat target in the south of its tenure, through to the Moorkai Dyke and Platinum Springs discoveries in the north.
Interestingly, some of the best results have come from the Red Hill prospect, immediately to the north of Little Broken Hill Gabbro, where drilling in 2020 returned a series of stunning intercepts, including 29m at 5.1 g/t palladium, 2.5 g/t platinum, 2.3 per cent copper and 0.4 per cent nickel, which placed the Broken Hill project firmly in the market’s spotlight.
Unseasonably wet weather in 2020 prevented Impact from drilling the prospects, resulting in the highly prospective targets being prioritised as a part of the company’s 2021 exploration schedule. Impact recently completed 68 drill holes and 5,532m of RC drilling across the Little Broken Hill Gabbro target, with the results from 48 holes having now been reported.
Recent drilling tested all three conceptual targets identified at Little Broken Hill Gabbro, with the Rockwell prospect returning the aforementioned results. Exploration at Rockwell shows the host stratigraphy extending over more than 1,500m of strike, with the mineralised horizon measuring up to 60m thick and extending to more than 150m below surface.
Higher-grade intervals from within the thick drill intercepts at Rockwell include 5m at 0.5 per cent copper, 0.4 per cent nickel and 0.6 g/t 3PGE which includes platinum, palladium and gold, from 161m down-hole.
Additional drilling at the Western Contact, 2km south of Rockwell, also intersected anomalous copper-PGE mineralisation whilst first-pass drilling over the Central LBHG prospect targeted the potential “feeder zone” to the PGE system.
A program of 30 aircore and reverse circulation drill holes over the Central LBHG outlined a 1km long, 500m wide geochemical target, with 12 holes returning anomalous nickel-copper-PGE mineralisation. It appears that the grade of the ore system is increasing at depth.
The best intercept at Central LBHG came from a deep RC hole and included 4m at 1.5 g/t gold and 0.13 per cent copper, which includes 1m at 4.5 g/t gold and 0.18 per cent copper from 150m down-hole, perhaps hinting that a larger and higher-grade ore system lies below the limits of the current drilling program.
With Impact’s maiden drilling program now complete at Little Broken Hill Gabbro and the rig now back at Apsley, the company is designing an extensive program of infill and extensional drilling over its Broken Hill targets as it looks to crack the PGE code in this world-class terrane in outback New South Wales – the drill is expected to be back on site at Broken Hill before the end of the quarter.
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