Transverse Structural Segmentation of the Transantarctic Mountains

该奖项将支持横贯南极山脉（TAM）内横向地质结构的研究，横贯南极山脉是沿南极东部和西部次大陆之间的地壳边界发育的主要大陆内山带。TAM表现为中新生代与南极板块内伸展构造作用有关的裂谷边缘隆升。TAM中的偏移表明了与其他大陆裂谷系统类似的沿走向构造分段。然而，与其他裂谷系统不同的是，裂谷段之间的倾斜方向没有变化，TAM中的横向结构与地理上的槽有关，这些槽可能代表张力“拉离”带。运动学分析将确定与这些构造相关的位移方向，并为在裂谷发育过程中调用东南极洲和西南极洲之间的扩展和平移的模型提供测试。这些横向构造的位置和特征的记录将提供裂谷系统的三维图像，这将约束裂谷发育和TAM隆起的过程导向模型。将TAM分割与其他裂谷系统的分割进行比较，将有助于评估大陆岩石圈在破裂前拉伸对沿轴裂谷传播的控制作用。

This award will support an investigation of transverse geologic structure within the Transantarctic Mountains (TAM), a major intracontinental mountain belt that developed along the crustal boundary between the subcontinents of East and West Antarctic. The TAM appear to be a rift-margin uplift related to extensional tectonism within the Antarctic Plate during the Mesozoic and Cenozoic. Offsets in the TAM suggest an along-strike structural segmentation analogous to that seen in other continental rift systems. In contrast to other rift systems, however, there is no change in tilt direction between segments, and transverse structures in the TAM are associated with physiographic troughs that may represent tensional "pull apart" zones. Kinematic analysis will establish the displacement direction(s) associated with these structures, and provide a test for models invoking extension and translation between East and West Antarctica during rift development. Documentation of the positions and character of these transverse structures will provide a 3-D picture of the rift system that will constrain process- oriented models of rift development and TAM uplift. Comparison of TAM segmentation with that of other rift systems will serve to evaluate controls on along-axis rift propagation as continental lithosphere is stretched prior to breakup.