A preliminary thermochemical model of the Australian lithospere

The Australian continent is composed of an assemblage of lithospheric blocks that can be broadly grouped into the Precambrian western and central cratonic zones and the Phanerozoic eastern province. The fusion of lithospheric domains, an active accretionary margin, and a sequence of subduction complexes throughout Australia's geological history have created a complex assemblage of lithospheric domains. In this thesis, I map the thermal, physical and compositional structure of this complex lithosphere and sub-lithospheric mantle using a well-developed multi-observable probabilistic inversion method (Afonso et al., 2013a,b).Geophysical observables used in this study include Rayleigh wave dispersion data, absolute elevation, geoid height, surface heat flow, and a priori crustal information (e.g. Mohodepth, crustal layers, seismic velocity and density). These data sets are jointly inverted using a 1D column-by-column approach with a Bayesian framework, combining prior geophysical knowledge with measured data.The results from this research include estimates of depth to the lithosphere-asthenosphere boundary, temperature variations and chemical structure in the lithosphere and sub-lithospheric mantle and temperature profiles beneath continental Australia.