Thermochronologic insight into late Cenozoic deformation in the basement‐cored Terskey Range, Kyrgyz Tien Shan
Thermochronologic insight into late Cenozoic deformation in the basement‐cored Terskey Range, Kyrgyz Tien Shan
复制标题
DOI：
10.1002/tect.20040
复制
发表时间：
2013-06
期刊：
影响因子：
4.2
通讯作者：
E. Macaulay;E. Sobel;A. Mikolaichuk;A. Landgraf;B. Kohn;F. Stuart
中科院分区：
文献类型：
--
作者：
E. Macaulay;E. Sobel;A. Mikolaichuk;A. Landgraf;B. Kohn;F. Stuart
陆内造山带逆断层作用形成的基底核岭，往往由多变形岩性组成。在这样的范围内，通常缺少能够约束最近变形阶段的时间、大小和分布的地质数据。在本文中，我们提出了新的低温热年代学和地质数据从一个横断面通过基底核心Terskey范围，位于吉尔吉斯天山。利用这些数据，我们能够研究范围的晚新生代变形的第一次。重新激活的断层上的位移受到约束，热年代学衍生的结构标志物的变形进行了评估。这些构造标志物晚于早期的变形阶段，提供了新生代变形和特斯基山脉内构造再活化的唯一记录。总的来说，这些构造标志物有一个南倾角，解释为反映了限制Terskey山脉的逆断层的倾角减小。我们的热年代学数据也被用于研究Terskey山脉折返的时空变化，确定了三个阶段的新生代折返历史：（1）在古近纪几乎没有折返，（2）在~26-20 Ma时增加到略高的折返率，（3）在~10 Ma时开始折返显着增加。
Basement‐cored ranges formed by reverse faulting within intracontinental mountain belts are often composed of poly‐deformed lithologies. Geological data capable of constraining the timing, magnitude, and distribution of the most recent deformational phase are usually missing in such ranges. In this paper, we present new low temperature thermochronological and geological data from a transect through the basement‐cored Terskey Range, located in the Kyrgyz Tien Shan. Using these data, we are able to investigate the range's late Cenozoic deformation for the first time. Displacements on reactivated faults are constrained and deformation of thermochronologically derived structural markers is assessed. These structural markers postdate the earlier deformational phases, providing the only record of Cenozoic deformation and of the reactivation of structures within the Terskey Range. Overall, these structural markers have a southern inclination, interpreted to reflect the decreasing inclination of the reverse fault bounding the Terskey Range. Our thermochronological data are also used to investigate spatial and temporal variations in the exhumation of the Terskey Range, identifying a three‐stage Cenozoic exhumation history: (1) virtually no exhumation in the Paleogene, (2) increase to slightly higher exhumation rates at ~26–20 Ma, and (3) significant increase in exhumation starting at ~10 Ma.