Collaborative Research: The suturing process: Insight from the India-Asia collision zone

大洋岩石圈俯冲后大陆碎屑的缝合作用是岩石圈动力学和地球-S大陆形成与生长的基本过程。然而，我们对这一根本进程的了解仍然有限。古缝合带在数千公里的区域构造、沉积和岩石学模式中表现出来，并记录了过去板块动力学的证据。缝合过程本身导致了板块动力学的剧烈变化，创造了地球上最大的S山脉，并通过关闭洋盆和抬高地形改变了全球气候动力学。就基本的全球构造过程而言，缝合作用等同于大洋俯冲和大洋中脊的形成，但在地球科学教科书中，除了它的定义和对印度-亚洲碰撞的顺带提及之外，几乎找不到更多的东西。该项目的主要目的是了解缝合前、缝合中和缝合后的地球动力学过程，以及这些过程如何影响大陆地貌并在地质记录中表达出来。为了实现这一目标，PI提议研究西藏南部和喜马拉雅北部的印度-亚洲碰撞带(IACZ)。将采用的技术包括构造地质学、地层学、地质年代学、热年代学、稳定和放射性同位素地球化学、火成岩和变质岩石学、古地磁学以及相关过程的地球动力学数值模拟。

The suturing of continental fragments following the subduction of intervening oceanic lithosphere is a fundamental process in lithospheric dynamics and the shaping and growth of Earth?s continents. However, our understanding of this fundamental process remains limited. Ancient sutures manifest themselves in regional structural, sedimentary, and petrologic patterns across thousands of kilometers, and record evidence of past plate dynamics. The suturing process itself results in drastic changes in plate dynamics, creates Earth?s largest mountain belts, and changes global climate dynamics by closing ocean basins and raising high topography. In terms of a fundamental and global tectonic process, suturing is on par with oceanic subduction and mid-ocean ridge formation, yet little more can be found in Earth-science textbooks than its definition and passing reference to the India?Asia collision. The primary aims of this project are to understand the geodynamic processes before, during, and after suturing, and how these processes impact continental physiography and are expressed in the geological record. To achieve this goal, the PIs propose to study the India?Asia collision zone (IACZ) in southern Tibet and the northern Himalaya. Techniques to be employed include structural geology, stratigraphy, geochronology, thermochronology, stable and radiogenic isotope geochemistry, igneous and metamorphic petrology, paleomagnetism, and numerical geodynamical modeling of the associated processes.