First images of Nullarbor plains geology released

Image: The Lead South Australia

New geological images have been released of the Nullarbor Plain, providing an insight into its mining potential.

The images were generated as part of a non-intrusive ground seismic survey conducted in collaboration between the Geological Survey of South Australia, Geoscience Australia, and the Geological Survey of Western Australia.

Two sets of images have been produced; one showing the depth, and the other showing the top 15km.

The images span across 484km, following Australia’s transcontinental rail line between Cook in South Australia and Haig in Western Australia, at depths of 60km.

The Geological Survey of South Australia’s Dr Rian Dutch said the new images would provide a better indication of where to find significant mineral deposits, according to a report by the Lead South Australia.

“The Nullarbor is a genuine, greenfield exploration area, so every little bit of information is a major value-add. When we combine ground seismic and airborne study results with information of the crustal conductivity, we can see dynamic regions where major crustal-scale structures come near the earth’s surface,” he said.

“These areas are generally more prospective as they provide pathways for fluids and magmas from the earth’s mantle to migrate into the upper-crust, potentially carrying valuable metals within reach of the surface.”

The images are the final part of the study completing a two-year, 834km study transect from Tarcooa in South Australia to Haig.

It is the largest study of its kind conducted in Australia.

The Nullarbor Plain has the largest area of limestone in the world; 200,000km2 and extending 1200km from east to west at its furthest point.

“The reason why it’s such a big frontier is because until we had done this work we had no idea how thick those limestone covers were,” Dutch said.

“This work has shown that the cover’s only 300-400m thick – the same sort of thickness as the cover over Olympic Dam – if you have a high grade deposit it becomes economic at those sorts of depths.

“In terms of the potential, it’s hard to tell at the moment because the data’s limited as to where the best spots are going to be but there are a couple of interesting anomalies on the South Australian side that have got a lot of people interested.”

Dutch went on to say that a drilling program will be conducted in 2017 for further assessment of the area.

The $3.15 million project garnered funding from partners Geoscience Australia and AuScope Earth Imaging with $1.4 million; with the South Australian Government providing $1.75 million through it’s Plan for Accelerating Exploration (PACE) plan.

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