Towards a multi-domain lithospheric model of East Antarctica

The knowledge of the lithospheric structure of East Antarctica is very limited and as a consequence we cannot produce accurate and precise maps of the subglacial geothermal heat flux density. Seismic tomography studies and potential field data can be used to derive lithosphere structure, but the resolution is relatively low, and the smoothed models don’t reflect the amalgamation of lithospheric terranes that formed the continent.

We combine geophysical constraints with geological knowledge from the sparse outcrops and known geology from Gondwanan neighbours in a plate reconstruction framework to attempt a regionalization of East Antarctica. We use Bayesian inference to suggest the most probable boundaries by using a multivariate prior constrained by available geophysical datasets. The boundaries form a segmentation of the Antarctic lithosphere and can be weighted with probabilistic significance and location. Our implementation allows sequential improvement as updated and refined seismic tomography and potential field data compilations. Likewise, a more consistent approach to adding mapped geological information adds further robust constraints.

The result is presented as a first draft of a multi-domain tessellated terrane map of the East Antarctic lithosphere. We believe that this approach will be useful in estimating both basal lithosphere and crustal contributions to heat flux. The approach provides a stepping stone towards more refined models in an evolving framework.