The Ross orogen of Antarctica is one of Earth's great Phanerozoic mountain belts. It is thought from igneous geochemistry, deformation patterns, and sedimentation history to be the result of late Neoproterozoic and early Paleozoic plate-margin convergence between paleo-Pacific oceanic lithosphere and continental lithosphere represented by the composite East Antarctic shield. Convergence along this margin is contemporaneous with, and tectonically linked to, amalgamation of the Gondwana supercontinent following collapse of former ocean basins and collision along the East African orogen. Although there is general agreement about the large-scale tectonic framework of the Ross orogen, there is a great deal of remaining...