Mesozoic and Cenozoic Kinematic Evolution of the Transantarctic Mountains

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This grant will support a field investigation of the Transantarctic Mountains (TAM), an intracontinental mountain belt that developed along the crustal boundary between the subcontinents of East and West Antarctica. Uplift of the TAM appears to be related to extensional tectonism within the Antarctic Plate during the Mesozoic and Cenozoic. The principal goal of this study is to document the kinematic history of the boundary between East and West Antarctica, both during the early stages of Gondwana break-up in the Jurassic and during the morphological development of the TAM in the Cenozoic. The work will focus on the Beardmore Glacier area of the central TAM and on a portion of the TAM in South Victoria Land where faults or dike swarms of demonstrated Jurassic and Cenozoic age are present. Detailed structural analysis of fault, fracture and dike arrays in these regions will be used to define Jurassic and Cenozoic regional strain kinematics and paleostress fields. These data will directly test existing models for Jurassic extensional and translational motions between East and West Antarctica, and will provide new constraints on Cenozoic displacements within the Antarctic plate that must be integrated into the Antarctic-Australia-Pacific plate circuit. The results will enhance our understanding of the tectonic evolution of the Antarctic plate and will have application to the general geotectonic problem of continental rifting and the development of rift-margin uplifts.