Mesozoic and Cenozoic Kinematic Evolution of the Transantarctic Mountains

这笔赠款将支持对横贯南极山脉（TAM）的实地调查，横贯南极山脉是沿东南极洲次大陆和西南极洲次大陆之间的地壳边界发育的大陆内山带。TAM的隆升与中新生代南极板块内部的伸展构造作用有关。本研究的主要目的是记录东、西南极洲边界的运动学历史，包括侏罗纪冈瓦纳板块断裂的早期阶段和新生代TAM的形态发育时期。这项工作将集中在TAM中部的Beardmore冰川地区，以及位于南维多利亚地的TAM的一部分，那里存在侏罗纪和新生代的断层或岩脉群。这些地区的断裂、裂缝和岩脉阵列的详细构造分析将用于定义侏罗纪和新生代区域应变运动学和古应力场。这些数据将直接测试南极东部和西部之间侏罗纪伸展和平动的现有模型，并将为必须整合到南极-澳大利亚-太平洋板块环路中的南极板块内新生代位移提供新的约束条件。研究结果将增强我们对南极板块构造演化的认识，并将应用于大陆裂谷和裂谷边缘隆升发育的一般大地构造问题。

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.