Carnavale Resources Ltd (ASX:CAV) will use helicopter-borne technology, which can identify targets deep in the earth’s surface, in its latest forays into the platinum group elements-nickel-copper prospective ground at the Barracuda Project in the Murchison district of Western Australia.
The 48 square kilometre area, 60 kilometres east of the gold mining town of Mt Magnet, is thought to contain deposits of platinum, palladium, nickel and copper concealed for decades until now.
The region, which is part of the Windimurra Igneous Complex (WIC), has been underexplored since Pancontinental Mining Ltd last mapped the area in the 1980s, with vastly less advanced technology.
Helicopter-borne survey
CAV has scheduled a detailed helicopter-borne Versatile Time Domain Electro-Magnetic (VTEM Max) geophysical survey, to commence next week, to seek concealed conductors that could host rich mineralisation.
The detailed helicopter-borne VTEM Max survey is targeting this style of concealed sulphide mineralisation at depth.
This technology can pinpoint discrete conductive anomalies while mapping lateral and vertical variations. Once the anomalies are found, drill targets can be mapped directly from the airborne results.
The survey will be flown at 200-metre line spacing with the electromagnetic sensor at 35 metres for 266-line kilometres. This system provides the highest signal/noise ratio and spatial resolution of conductors.
Other ASX companies have successfully used the VTEM Max technology to define basement mineralisation.
Historical evidence
Pancon held exploration licences over most of the WIC between 1985 and 1990 and conducted geological mapping and drainage sampling.
Its investigations culminated in the discovery of outcropping magmatic chromium, nickel, copper and PGE mineralisation in the late 1980s, and supports the potential for mineralisation at depth.
Multiple coincident platinum and palladium geochemical anomalies were defined by Pancon's soil sampling program with a strike length of more than 4 kilometres.
Pancon’s soil assay data was compiled in analogue form and CAV has digitally remodelled the data from these old diagrams.
The company hopes to combine this information with the results of its VTEM survey to confirm new drill targets.
Only 1,811 metres of drilling was ever completed by Pancon. No further holes were drilled after 1988 and no further exploration for magmatic PGE-nickel-copper sulphide has been conducted in the area since 1990.
In 2008, an aerial electromagnetic geophysical survey (RepTEM) was flown on 400-metre line spacing as part of a large-scale regional survey.
Geophysical, remote-sensing electromagnetic technology has improved significantly even since then, but the survey nevertheless adds weight to the evidence that CAV is onto something.
There appears to be stronger conductors in the southern portion of the tenement area that are not covered by the Pancon soil program and represent possible targets to be enhanced by the upcoming VTEM Max survey.
CAV believes that this enhances the prospectivity of the tenement area.
Similarities to South African geology
Along with the evidence from Pancon’s activities at the site nearly four decades ago, there are several references in geological research papers that provide an indication of the prospectivity of the project.
The project lies on the northwestern edge of the WIC, which is described as the largest exposed single-layered igneous intrusion in Australia. The area is the focus of much geological interest because of its similarity to the lucrative Bushveld Igneous Complex in South Africa, which hosts 75% of the world’s platinum and about half its palladium, and the potential for correlative mineral wealth.
CEO Humphrey Hale commented: “We have compiled the graphical data from early Pancon reports into our digital database and have integrated this information with recently acquired remote sensing data.
“The geochemistry, geophysics and geology of the tenement area support CAV’s exploration model that the Barracuda Project has the potential to host significant PGE-nickel-copper sulphide mineralisation.
"This detailed survey will be able to see further than ever before, beneath the surface to detect conductive sulphide bodies.”
Exploration strategy
CAV’s planned fieldwork program at the Barracuda project includes flying the project area with VTEM in the next week, following up any airborne VTEM anomalies with ground EM, paying special attention to the areas with established, coincident copper, nickel and platinum-group soil anomalism, and finally, drill-testing targets subject to these results.