Special Report: Early exploration at Impact Minerals’ Rockwell prospect has discovered strongly anomalous nickel-copper-platinum group (PGE) element mineralisation over a distance at least 1500m.  

The Rockwell prospect is part of Impact Minerals’ (ASX:IPT) Little Broken Hill Gabbro area at the 100% owned Broken Hill project in New South Wales.

The mineralisation was discovered during the first ever drill program at Little Broken Hill Gabbro, which involved first-pass reconnaissance drilling and portable X-ray fluorescence (XRF).

It identified disseminated copper sulphide present in zones up to 25m true thickness, increasing to the south towards an interpreted feeder zone for magnetic nickel-copper-PGE sulphides at Rockwell.

Disseminated nickel sulphides also occurred in one-to-two-metre-thick layers within the copper sulphide zones.

Assays are pending for all holes containing the disseminated sulphides.

Despite this, Impact Minerals said new assays and handheld XRF data indicated that mineralisation appeared to increase in thickness and grade from north to south.

This leads into a priority target area interpreted to contain potential feeder zones to the main Little Broken Hill Gabbro.

The feeder zones are fault-controlled conduits through which hot magma migrates into a larger intrusion from depth – common sites for nickel-copper sulphide deposits.

The mineralisation occurs mostly in an ultramafic unit at the base of Little Broken Hill Gabbro, and Impact said this confirmed the highly prospective nature of the entire six-kilometre-long intrusion for magmatic nickel-copper-PGE sulphide deposits.

The company believes Little Broken Hill Gabbro is of a similar size, age, chemical composition and in the same geodynamic setting as the giant Jinchuan nickel-copper-PGE deposit in China – 550 million tonnes at 1.1% nickel, 0.7% copper and 0.5 grams per tonne PGE.

The company said initial scout drilling results were considered very encouraging for the discovery of a deposit in the same style as Jinchuan.

Impact Minerals
Impact Minerals’ landholding at Broken Hill. Pic: Company supplied.

The results so far

Results from drilling so far have been highly promising and include the following assays.

  • 6m at 0.72g/t 3PGE and 760ppm copper from surface, including 1m at 1.2g/t 3PGE and 0.2% copper from 4m in hole LBIPT026;
  • 7m at 0.2g/t 3PGE and 0.2% copper from surface and 3m at 0.26g/t 3PGE and 0.15% copper from 23m in LBIPT027;
  • And 36m at 0.1g/t 3PGE from 2m including 6m at 0.3g/t 3PGE from 24m in hole LBIPT025, which did not reach depth.

Assays for further holes are awaited.


Next steps for Impact

Impact said the results showed a need for extensive follow-up drilling at Rockwell and likely also in other parts of the Little Broken Hill Gabbro.

Having already gathered a large amount of new data, the company is still awaiting assays from all four prospects at its Broken Hill deposit, including Little Broken Hill Gabbro, Platinum Springs, Red Hill and Dora East.

Detailed interpretation of the new data in context is required to prioritise areas for follow up drilling, and further drilling will resume as soon as practical in the first quarter of 2021.

Expect plenty of newsflow from Impact Minerals in the early part of the new year.

This article was developed in collaboration with Impact Minerals, a Stockhead advertiser at the time of publishing.


This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.