Australian explorer Impact Minerals (ASX: IPT) has posted a strong quarter of exploration activity at its base metals projects on the country’s east coast.
A major drilling program kicked off in August at the Broken Hill nickel-copper-platinum group elements project, to test priority prospects at Red Hill, Platinum Springs and Little Broken Hill Gabbro.
The program commenced at Platinum Springs, which lies at the southern end of the 9km-long Moorkai Trend hosting high-grade nickel-copper-PGEs.
Drilling was designed to follow up a previous intercept of 0.6m at 11.5 grams per tonne platinum, 25.6g/t palladium, 1.4g/t gold, 1.3g/t rhodium, 1.7g/t iridium, 2g/t osmium, 0.8g/t ruthenium, 7.6% copper and 7.4% nickel.
Impact said the combined assays from previous drill holes at Platinum Springs have defined an area which is at least 200m long and up to 20m wide, at greater than 1g/t combined PGEs.
“[Our work] suggests that a Kambalda-style structural channel or even chonolith is a more appropriate geometric model to follow,” the company said.
“Such styles of nickel-copper-PGE sulphide mineralisation are more challenging to discover but once confirmed, can persist for long distances down plunge.”
Little Broken Hill
During the quarter, Impact received a grant of $75,000 from the New South Wales Government for drilling at Little Broken Hill, under the New Frontiers Co-operative Drilling initiative.
An extensive aircore and reverse circulation program is set to test a 4km-long part of the intrusive complex under shallow cover and not previously drilled.
Impact said ongoing interpretation of airborne magnetic data and rock chip geochemistry assays had identified “some compelling drill targets” in the area.
The company confirmed a new interpretation of airborne magnetic data over the Red Hill to Little Broken Hill Gabbro (LBHG) area has shown it is of the same scale as – and contains similar internal structures to – those that host many of the world’s major nickel-copper-PGE deposits such as Jinchuan and Voiseys Bay.
“The LBHG is evident in airborne magnetic data and is about 6km long and up to 1km thick … there are no detailed published studies on the gabbro and it is poorly understood,” the company said.
For the three months to September, strong progress was made at several prospects within the Commonwealth project in the Lachlan Fold belt in NSW.
“Very high-grade silver and gold results from the Gladstone and Greenobbys prospects have brought back into focus the fact that [our] ground holdings cover an exceptionally silver-rich part of a mineral province best known for its major copper-gold deposits such as Cadia-Ridgeway, North Parkes and the recent discovery at Boda,” Impact said.
The Gladstone, Greenobbys and Boda South prospects were identified together with the Apsley and Spicers Creek prospects by Impact as priority areas for follow up exploration in late 2019.
All five priority areas were covered by an airborne magnetic and radiometric survey and Apsley was prioritised for follow-up soil geochemistry because of widespread copper mineralisation found at surface.
Two new applications for wholly-owned mineral exploration permits within the Blackridge conglomerate-hosted gold project in central Queensland were lodged during the quarter.
Applications for Pewt’s Hill and Hard Hill will join an existing granted permit and mining lease to total 150sq km of acreage and give Impact ownership of about 90% of the historic Blackridge goldfield.
The goldfield forms the southern half of the greater Miclere-Blackridge area which produced over 300,000 ounces of gold in the late 1800s and early 1900s.
Impact has been actively exploring at Blackridge since mid-2018 following an option agreement with Rock Solid Holdings Pty Ltd to acquire a 95% interest in one exploration permit and four mining lease applications.
Rock Solid allowed its permit to lapse earlier this year and the area is now covered by one of Impact’s new licences.