Crust and upper mantle in Dronning Maud Land/Antarctica retrieved from shear-wave splitting, receiver functions, seismic refraction and 3-D gravity modelling

The crust and upper mantle of Dronning Maud Land (DML), Antarctica, have been investigated using teleseismic data from broadband seismograph stations deployed at temporary and permanent locations and recordings from a seismic refraction experiment. For shear-wave splitting analyses the observed anisotropy can in most cases be related to major tectonic events that formed the geological features of the present-day Antarctic continent. We rule out an anisotropic contribution from recent asthenospheric flow. An abrupt change in fast axis direction of the shear-waves as well as a remarkable Moho jump beneath the Kottas mountains appears to mark a suture between the Grunehogna craton, a fragment of the Kalahari-Kaapvaal craton in southern Africa, and the Mesoproterozoic Namaqua-Natal belt. In general, the Moho increases from the coast towards the mountain ranges of Wohlthatmassif and Kottas, where thick crust between 45-53 km is found. The Vp/Vs-ratio are similar within geological units but different throughout DML.