Formation of the Transantarctic Mountains related to extension of the West Antarctic Rift system

Abstract

The Transantarctic Mountains are a major rift-related mountain belt bisecting the Antarctic continent. The range is located on the tectonic boundary between non-cratonic West and cratonic East Antarctica. Formation of the mountain range and a possible relation with the West Antarctic Rift system are unclear. In this study, we find a new explanation for uplift of the Transantarctic Mountains and suggest a relation between uplift of the range, formation of a small crustal root, depression of the hinterland Wilkes Basin, and the formation of the adjacent West Antarctic Rift system. Numerical models show that upon extension of the Antarctic lithosphere, the West Antarctic Rift system is formed on the tectonic boundary between East and West Antarctica. Convergence of crustal material results in crustal thickening and uplift of the Earth's surface on the cratonic side of this rift zone, and formation of the Transantarctic Mountains. Some models predict a depression in the hinterland of the mountain range at the location of the Wilkes Basin. These models predict that the Wilkes Basin is a non-extensional basin caused by flexure of the lithosphere. This study shows that inherited lithosphere structures play an important role in localization of both extensional and convergent deformation.