This theme addresses the use of geophysical techniques to map the physical properties of both cover and basement rocks and, by proxy, to infer the composition and structure of the crust. These physical properties include density, magnetisation, electrical resistivity and chargeability, and seismic velocity. They can be mapped by measuring subtle variations in the Earth's gravity and magnetic fields, by measuring variations in electrical currents passed through the crust and by seismic surveys.
This theme will be closely linked into the 'Tectonics and Metallogeny' and 'Regolith and Landscape Development' themes as it provides a means of mapping the deep crust in three-dimensions. Furthermore, since many mineral systems contain rocks with anomalous physical properties, geophysical techniques provide the potential to define specific exploration targets. For example, the Iron-oxide Cu-Au-U deposits of South Australia, including the giant Olympic Dam deposit, are significantly more dense than their host rocks and can be predicted to produce a small but detectable variation in the Earth's gravity field.
The CMXUC strategy is to use a variety of geophysical techniques where appropriate to specific geological problems - gravity, magnetics, eletro-magnetics (EM), magnetotellurics (MT), induced polarisation (IP). By mapping the surface and sampling drill core, a library of petrophysical measurements and surface observations with which to constrain our geophysical modelling will be built.
This work will build on expertise developed at the University of Adelaide, particularly in the application of MT and EM techniques and in analysis of gravity and magnetic data, and on the excellent statewide geophysical databases acquired by PIRSA over a 15 year period.
Current Research Projects
- Geodynamics of the Marginal terranes of the South Australian Craton (An ARC Funded Linkage Project - LP0882000)
Three-dimensional magnetotelluric imaging of lithospheric-scale mineral systems from source to deposit - (An ARC funded Linkage project - LP0774891)
- Evolution of the Adelaidean Basin
- Adelaidean Geothermal
- Structural and heat flow modelling of the Hallet area
- Bridging the gap between the South and Northern Australian Cratons
- Fowler Belt Geodynamics