Special Report: Drilling at Impact’s Rockwell prospect has returned good grades of platinum+palladium+gold (3PGE) with copper and nickel over at least 400m of strike.

Results from five holes at Rockwell, part of the Little Broken Hill Gabbro (LBHG) within the Broken Hill project in New South Wales, indicates the ultramafic unit contains robust widths of up to 60m of 3PGE mineralisation with individual assays of up to 2.6 grams per tonne (g/t) 3PGE, 1.1 per cent nickel and 0.7 per cent copper.

Impact Minerals (ASX:IPT) added that mineralisation appears to increase in thickness and grade at depth and to the south while remaining open in all directions.

“These new assays demonstrate that the basal ultramafic unit of the LBHG contains thick widths of modest grades of PGE, nickel and copper with higher grades in many places over a significant strike extent. The LBHG is basically starting to light up like a Christmas tree,” managing director Dr Mike Jones said.

“Given that our drill program is the first ever to test the basal unit, which extends over the entire 6.5km long extent of the intrusion, further supports our growing belief that the LBHG may potentially contain a vast reservoir of PGEs and possibly nickel and copper.”

Broken Hill drilling

The LBHG is believed to be of a similar size, age, chemical composition and in the same geodynamic setting as the giant Jinchuan nickel-copper-PGE deposit in China.

Impact has completed 28 holes at Rockwell with assays from the earlier 13 holes returning strongly anomalous copper, nickel and PGE mineralisation.

Assays for the remaining 10 holes are expected to be released in January 2021.

The company has also drilled a further 41 holes in the central part of the LBHG to test the upper parts of the target, which are dominated by rocks of gabbro composition rather than ultramafic as found at the base.

Assay data released to date suggests that the proprietary ratio calculated for PGE exploration is a very good guide to the presence or absence of PGEs at the LBHG.

However, there is relatively poor correlation with grade compared to Platinum Springs, which the company believes may be due to the different rock geochemistry. Further research is underway.


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.