Conforming satellite and airborne magnetic data and linking East Antarctica its ancient Gondwana neighbours

Abstract:

The tectonic build-up of East Antarctica is still not well understood and linking to the formerly adjacent continental areas of Australia and Southern Africa can ease interpretation. Modern aeromagnetic datasets exist for these areas, but do not necessarily fit, most notably between Antarctica and Southern Africa. The mismatch could be interpreted because of the different tectonic evolution since break-up, but as we show here partly result from inaccurate representations of the long-wavelength magnetic field. After conforming all compilations to a common, recent satellite magnetic model (LCS-1), the data match to a large degree.

For India, no high-resolution aeromagnetic data set is available. Instead, we use the satellite data directly to include India in the interpretation in a Gondwana framework. As India is located north of the magnetic equator, we also performed a variable reduction to the pole to the satellite data by applying an equivalent source method.

The satellite and aeromagnetic anomaly datasets help portraying the extent and architecture of older Precambrian cratons, re-enforcing their linkages in East Antarctica, Australia, India and Africa.