Long-term crustal deformation in the Pamir: Tertiary continental subduction, crustal bucking, and orocline formation

帕米尔高原的长期地壳变形：第三纪大陆俯冲、地壳弯曲和逆斜形成

• 批准号: 140596706
• 负责人: Professor Dr. Jonas Kley
• 金额: --
• 依托单位: Institut für Geologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/140596706?language=en
• 关键词: Long; term; crustal; deformation; Pamir

We aim to establish the Tertiary deformation of the Pamir–southern Tien Shan on a middle-upper crustal scale, including the first-order structural geometry of intra-continental subduction/crustal buckling, the kinematics of orocline formation, and the modes of tectonic denudation. Our hypothesis is that long-term deformation is concentrated in thick-skinned fold-thrust belts, tracing three continental subduction zones that were partly active contemporaneously; the subduction shortening produced basement domes that stretch across the Pamir and that were later accentuated by orocline formation and indenter rotation. We propose combined structural-geochronologic studies in: (1) the Tajik basin and the intra-montane Alai valley encompassing the southern Tien Shan and the Pamir frontal ranges; (2) the Yazgulem–Muskol–Sares basement domes of the central Pamir; and (3) the Shakhdara dome of the southern Pamir. We will use balanced cross section, stress-field, ductile flow, and kinematic studies together with U/Th/Pb, Ar/Ar, fission-track, and (U-Th)/He geochronology. This project is regionally and methodologically interwoven with the surface-process (CRP3, 5) and the crust/mantle-process aspects (CRP1, 4) of TIPAGE and collaborates with an associated US-project that will provide the petrologic (pressure-temperature) data for the Tertiary deformation history. Its data are pre-requisite to constrain and interpret the long-term geodynamic aspects of numeric modeling in TIPAGE.

我们的目标是建立第三纪变形的帕米尔-南天山在中上地壳的规模，包括一级结构几何的陆内俯冲/地壳屈曲，运动学的造山带形成，构造剥蚀的模式。我们的假设是，长期变形集中在厚皮褶皱冲断带，跟踪三个大陆俯冲带，部分同期活动;俯冲缩短产生的基底圆顶，横跨帕米尔高原，后来加剧了造山带的形成和缩进旋转。我们建议在以下地区进行构造-年代学联合研究：（1）塔吉克盆地和包括天山南部和帕米尔前缘山脉的山内阿莱河谷;（2）帕米尔中部的Yazgulem-Muskol-Sares基底穹隆;（3）帕米尔南部的Shakhdara穹隆。我们将使用平衡截面，应力场，韧性流动和运动学研究，以及U/Th/Pb，Ar/Ar，裂变径迹和（U-Th）/He年代学。该项目在区域和方法上与TIPAGE的表面过程（CRP 3，5）和地壳/地幔过程方面（CRP 1，4）交织在一起，并与相关的美国项目合作，该项目将提供第三纪变形史的岩石学（压力-温度）数据。它的数据是约束和解释TIPAGE数值模拟的长期地球动力学方面的先决条件。