The deep lithospheric structure of the South Australian Craton revealed by teleseismic Rayleigh wave tomography

We used teleseismic Rayleigh waves recorded on three recent broadband seismic ar-rays in southern Australia to develop a shear wave velocity model of the South Australian Craton from the lower crust to 250 km depth and compare this with isotope data, xenolith data, and 3D mantle resistivity structure. At ∼75-150 km depth, the seismic expression of cratonic lithosphere encompasses the eastern Gawler Craton, Curnamona Province and intervening Adelaide Super-basin north of ∼33◦S. The inference of contiguous cratonic lithospheric mantle between the Gawler Craton and Curnamona Province may have implications for models of Rodinia breakup. Cratonic lithospheric mantle is modelled as terminating substantially inboard of the conventionally-defined western margin of the Gawler Craton, but extending southward and northeastward beyond the conventionally-defined boundary of the Curnamona Province. Geophysical signatures of cratonic lithospheric mantle are absent under the southern Eyre Peninsula, possibly related to the Jurassic-Cretaceous separation of Australia and Antarctica. At depths >150 km, the deep cratonic keel is re-stricted to the eastern Gawler Craton and southern Curnamona Province. Major iron oxide-copper-gold (IOCG) deposits of the eastern Gawler Craton (e.g., Olympic Dam) and Curnamona Province reside above regionally seismically-fastest lithospheric mantle. This seismic signature might pro-vide a useful precompetitive vector for IOCG prospectivity mapping.

Citation: O’Donnell, J. P., Selway, K., Wade, C., Thiel, S., Eakin, C., Pickle, R., Agrawal, S., Goleby, B., & Gorbatov, A. 2025. The Deep Lithospheric Structure of the South Australian Craton Revealed by Teleseismic Rayleigh Wave Tomography. Seismica, 4(2). https://doi.org/10.26443/seismica.v4i2.1772