345 - The Wilkes Land sector including the Aurora Basin, and its most probable subglacial geology

With no direct observations, the subglacial geology of the Antarctic interior is unknown. However, with a growing awareness of the complex interaction between the ice sheet and the solid Earth, there is a need for well-posed estimates of properties such as crustal heat production, extent and thickness of sedimentary basins, and timing and extent of exhumation. Constraining the likely nature of the bedrock is also the key to a better understanding of the tectonic history of East Antarctica, e.g. the extent of cratonic blocks and orientation of Proterozoic orogens.

We present a probabilistic approach to describe the range of possible interpretations of the Antarctic interior with a focus on The Wilkes Land sector, including the Aurora Basin. Along the coast, we utilize geological observations and tectonic reconstructions of Gondwana. In the interior, the constraints depend more heavily on geophysical data. We use the geological and geophysical data to construct 'membership functions' that quantify the likelihood of a given property of the subglacial geology. Properties include tectonic affiliation, crustal type and crustal stabilisation age. The membership functions are defined from a range of classification and regression methods, assembled in a novel workflow using the agrid package and provided Python code. The outcome is treated as a likelihood distribution and combined with expected prior values, for each property mapped.

Our resulting outputs and interpretations, including most likely broadscale bedrock geology, are made available as maps in widely usable formats for use in the wider geoscience and interdisciplinary Antarctic research communities.