News Illuminating northern Australias geology

A new electrical conductivity model released by Geoscience Australias Exploring for the Future program offers a fresh look at mineral prospectivity in northern Australia.

Data for the model was acquired from December 2016 to December 2019 under the Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP). It covered more than one million square kilometres of the Northern Territory and western Queensland.

The new model reveals several promising features, including prominent electrical conductors which may represent the deep-Earth footprint of large mineral systems in this under-explored region. For the first time the model shows conductors in the Tanami Province, an area known for its gold mines, and could be used to target exploration elsewhere in the region and in the Aileron Province.

Early analysis shows strong correlations with iron oxide-copper-gold systems, orogenic gold systems and other copper/gold related mineralisation.

Similar models in other parts of Australia have revealed that large mineral deposits at Olympic Dam in South Australia and Ernest Henry in north-west Queensland are connected to broad conductivity anomalies in the deep Earth via narrow conductive pipes. These features are inferred ancient pathways along which metals migrated to the near-surface and formed mineral deposits.

AusLAMP is a long-running collaborative national survey, imaging the electric structure of the Australian continental lithosphere in three dimensions (3D). AusLAMP is led by Geoscience Australia in collaboration with the State and Northern Territory geological surveys, universities, AuScope and other research organisations.

AusLAMP deployment is planned in north Queensland and eastern Western Australia in 2022 as part of the Exploring for the Future program.

The AusLAMP model of northern Australia is now available. The 2Dand 3D versions of the model are available through the Exploring for the Future Data Discovery Portal.