A recent model (Bialas et al., 2007) proposes that the Transantarctic Mountains (TAM) are the remnant edge of a collapsed plateau.  In this model, the West Antarctic rift system/TAM region was a plateau (the "West Antarctic Plateau") with thicker than normal crust before undergoing a topographic reversal. Plateau collapse was due to continental extension and concomitant denudation beginning in the Jurassic when widespread tholeiitic magmatism marked initial rifting between East and West Antarctica. This was followed by the major period of West Antarctic extension in the Cretaceous and then more localized extension in the western Ross Embayment in the Paleogene and Neogene.  The West Antarctic plateau formed inboard of subduction zone that existed along the Pacific margin of Gondwana throughout the Paleozoic until the late Mesozoic. The remnant plateau edge, now supported by slightly thickened crust, represent the ancestral TAM that remained following plateau collapse.