Surveys reduce exploration risk

07 August 2012

Large regional airborne electromagnetic (AEM) surveys carried out over two States and the Northern Territory have provided further evidence that Australia presents opportunities for significant new energy and mineral resource discoveries.

The surveys were carried out over three years in the Paterson region of Western Australia, the Frome region in South Australia and the Pine Creek region in the Northern Territory.

Presenting to the International Geological Congress in Brisbane today, Geoscience Australia geologist, Dr Ian Roach, said that the surveys had provided reliable pre-competitive AEM data which helped to reduce exploration risk for energy resources, mineral deposits and groundwater sources.

Dr Roach said that the survey data was processed using innovative layered earth inversion techniques developed by Geoscience Australia and delivered in a variety of formats to suit geological and geophysical explorers, researchers and the public.

"The results confirm the value of regional AEM surveying for interpreting large-scale geological features and basin architecture as well as obtaining local detail," Dr Roach said.

"It has helped to improve our understanding of the geology under the surface cover and aid the development of 3D models of the geological features within the Earth," he said.

The survey in Pine Creek also achieved a world first with the aid of the Versatile Time Domain Electromagnetics (VTEMTM) system to reveal geological features to depths approaching two kilometres, well beyond those previously recorded by airborne systems.

The survey in the Frome region was the most extensive ever undertaken by Geoscience Australia, covering 95 450 square kilometres from the Frome Embayment to the northern Murray Basin, east and north of the Flinders Ranges representing almost 10 per cent of South Australia’s total area.

Dr Roach said the three surveys provide high quality pre-competitive data which further support the possibility for the discovery of energy and mineral resources under cover in areas with existing mineralisation as well as in unexplored areas.

AEM surveys involve transmitting an electromagnetic signal from a wire loop attached to an aeroplane or helicopter. The signal induces electric currents in the ground which are detected by receiver coils towed by the aircraft. Depending on the system used and the subsurface conditions, AEM can reliably detect variations in the electrical conductivity of the ground to a depth of around 300 metres. This allows the identification of a range of geological features which can indicate the presence of certain minerals or groundwater.

For more information or to arrange interviews, please contact: Geoscience Australia 24 hour Media Hotline 1800 882 035

Topic contact: Last updated: October 4, 2013