Helix Resources Ltd (ASX:HLX)’s ongoing copper-gold discovery program at the Black Range prospect, in the Cobar-Nyngan area of central NSW, is yielding promising results in a previously undrilled area.
The company is confident it’s on the verge of defining a regional-scale polymetallic anomaly in the area, following an initial reverse circulation (RC) drill program to test a copper target at the Black Range prospect on the Rochford Trend.
Regional scale polymetallic mineralisation
RC holes intersected broad zones of iron (pyrite) and copper (chalcopyrite) sulphide mineralisation associated with intermittent intervals of anomalous copper including:
- 1 metre at 1.11% copper within 8 metres at 0.35% copper from 126 metres; and
- 2 metres at 1.44% copper within 8 metres at 0.63% copper from 76 metres.
These initial two drill holes focused on the eastern end of the large-scale Black Range copper-bismuth anomaly near two historical shallow shafts, with the aim of assessing the mineralisation style and orientation before ‘stepping out’ to test the full 6-kilometre east-west trending extent of the anomaly.
The drilling intersected intervals of massive pyrite and chalcopyrite veins and disseminations within a 450-metre-long north-northwest-trending mineralised zone defined by gossan outcrop and anomalous rock chip and lag geochemistry, which is open to the north and south.
Preliminary interpretations suggest that the 6-kilometre anomaly may encompass a series of north-northwest trending structures that are mineralised.
The multi-element geochemical anomaly comprising copper and bismuth with indium, tin, tungsten and zinc is consistent with an intrusive-related mineralising system.
This geochemical signature, along with extensive sulphide mineralisation, points to a different style of mineralisation to that delineated at Canbelego Main Lode and described as ‘Cobar-style’.
“At the Black Range prospect, we have delineated a significant, regional-scale polymetallic anomaly with an intrusive-related geochemical signature,” Helix managing director Mike Rosenstreich said.
No previous drilling in the area
“While there are numerous scattered historical copper-mine workings, there has been no previous drilling in the area and the initial RC drilling recently completed by Helix intersected significant pyrite and chalcopyrite mineralisation.
“The style of mineralisation observed suggests something a bit different for the region – than the ‘Cobar’ copper lode model we have at Canbelego.
“The large-scale and multi-element nature of the anomaly, now supported by highly anomalous drill intercepts leads us to look within the broader anomaly area to define further drill targets, particularly in potential parallel zones immediately west of Black Range.”
What’s next?
The next steps are to plan for the next drilling program at Black Range, which will require extensive approvals for site clearance given the rugged terrain.
The company has also planned a 3,000-metre drilling program for early November at the Bijoux prospect, some 20 kilometres southeast of Black Range along the Rochford Trend.
“Helix has a commanding land position in a highly endowed copper (and gold) province – where we are generating new targets and testing them with the drill bit,” said Rosenstreich.
“It’s a numbers game – the more targets you test the greater chance of discovery. The team is working hard making new copper discoveries and I look forward to providing further updates.”
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