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The world’s mineral exploration community now has more information about the geology beneath South Australia’s Gawler Craton following a new geological data release today.

The State Government’s Geological Survey of South Australia and collaborative partner Geoscience Australia today issued a set of ground-breaking seismic images of the earth’s crust along a 350 kilometre stretch.

Department of State Development Executive Director Mineral Resources Ted Tyne said the first stage of the Eucla-Gawler Seismic Survey data release will open the door to new opportunities for mineral and energy exploration across a vast area of the state. 

“This release is supported through the government’s PACE initiative, and will kick-start exploration activity in a largely under-explored region,” Dr Tyne said.

“It will lay the foundation for possible discoveries of important mineral assets and a pipeline of future mines, with the potential to benefit regional communities for generations to come.”

The seismic data, which is free to download online, follows the area geologically known as the western Gawler Craton from Tarcoola in central South Australia to the eastern edge of the Nullarbor. This area is known for its previously discovered gold mineralisation.

Eucla-Gawler Seismic Survey line location map 

“This new information forms part of a massive 834km cross-border survey that extends from Tarcoola to Haig in Western Australia,” Dr Tyne said.

“It is a major achievement and a result of collaboration between our own Geological Survey of South Australia, the Geological Survey of Western Australia, Geoscience Australia and AuScope Earth Imaging.”

Geological Survey of South Australia Geologist Dr Rian Dutch said the international exploration community can now get better information about the area.

“The first-stage release provides two versions of seismic data,” Dr Dutch said.

“The first version provides an image of the Earth’s crust to a depth of 60km; the second shows the upper 25km in greater detail, which will greatly aid explorers in their hunt for mineral deposits near the earth’s surface.

"The whole point of the data set is to image the whole of the crust, which allows an understanding of the regional geological setting and tells us about the structural architecture and geological history of the region; it also potentially reveals areas of raised mineralisation.

“The survey highlights dynamic regions where major crustal-scale structures come near the earth’s surface, which are important because they provide pathways for fluids and magmas from the mantle to migrate into the upper-crust, potentially carrying valuable metals within reach of the surface.

“An exciting highlight emerging from the study is confirmation of deep structures and granite bodies likely to be connected to the geologically renowned Hiltaba Suite in the central Gawler Craton west of Tarcoola, and they point to raised prospects of finding gold and iron oxide copper gold in this region.”

Geologists keen to understand the implications from the data releases are encouraged to download the data and attend a workshop on 10 December, a day before the South Australian Exploration and Mining Conference.

The workshop includes seven national specialists who will outline study methods, recap existing geological knowledge, and cover survey data together with an interpretation and models of study data.

Dr Dutch said interpretation of the seismic data will be enhanced by the release of supporting gravity and magnetotelluric modelling at the workshop.  

“The magnetotelluric data will draw widespread interest as it provides a picture of the electrical properties of the crust, which together with the new seismic data can reveal regions where potential mineral-bearing fluids have moved and deposited metals of economic interest,” he said.

Next year, the Eucla-Gawler seismic data release will be further complemented by a broader package of pre-competitive knowledge.

This will be aimed at understanding the mineral potential of the Western Regions of South Australia, with data from the Coompana Airborne Magnetic and Radiometric Survey and release of the western half of the Eucla-Gawler seismic line.

The South Australian Government has contributed $1.75 million to the $3.15 million Eucla-Gawler seismic South Australian segment, with its collaborative partners Geoscience Australia and AuScope Earth Imaging providing the remaining $1.4 million.

The body of knowledge generated from the Eucla-Gawler Seismic Survey will complement the PACE Copper initiative announced this week by the State Government.

More about the survey and data release 

Released Wednesday 2 December 2015