Alessandro Maritati1, Jacqueline Halpin1, Joanne Whittaker1,
1Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
Heat produced by radioactive decay within East Antarctic crust provides a significant contribution to the total heat flow balance that is supplied at the base of the East Antarctic Ice Sheet. However, the distribution of heat-producing crustal rocks in ice-covered regions remains poorly constrained. Wilkes Land, East Antarctica hosts the Totten Glacier catchment area, one of the largest ice drainage basins in East Antarctica, and is one region where an improved knowledge of sub-glacial geology is of fundamental importance to understanding solid Earth-cryosphere interactions.
We examined the provenance of three low-grade quartzite erratic samples from the Windmill Islands region to provide evidence of the age and composition of the ice-covered bedrock. We suggest these quartzite erratic samples were sourced from a previously-unknown intra-continental sedimentary basin in the interior of Wilkes Land. U–Pb ages of detrital zircons include dominant age peaks at c. 1200 Ma and c. 1490 Ma, which fingerprint the provenance of this sedimentary basin.
Based on the detrital zircon record in these quartzite erratic samples, and using recent Australia-Antarctica plate reconstructions, we suggest there are heat-producing granitic source rocks in Wilkes Land equivalent in age and composition to those present in the Coompana Province of southwestern Australia. We further suggest that the significant heat production variability that characterises the Coompana granitic basement (2.52–6.39 μW/m3) can therefore also be expected in the interior of Wilkes Land. These new geological insights indicate that a higher and more variable regional sub-glacial heat flow might be expected in this region than currently resolved in available models.