Cretaceous Gondwana breakup between East Antarctica and India was accompanied or followed by emplacement of the Kerguelen Plateau Large Igneous Province (LIP), north of Prydz Bay. During Polarstern expedition ANT-XXIII/9 in early 2007, deep crustal seismic and helicopter-magnetic surveys were conducted along a corridor between the southern Kerguelen Plateau and the outermost Prydz Bay. These surveys were designed to investigate breakup processes and the effect that the igneous activity had on the formation of the passive margin of East Antarctica and also the apparent oceanic crust between the plateau and the Antarctic margin in the Princess Elizabeth Trough (PET). Preliminary data analysis and modeling reveal a wide zone of highly extended continental crust on the margin of Mac.Robertson Land and that the southernmost Kerguelen Plateau is generally of continental affinity. Seismic velocities and magnetic data indicate an oceanic-type crust beneath the PET. Magmatic accretion to this crust from the Kerguelen LIP is widely observed.