Geometry and Kinematics of the Taiwan Arc-Continent Collision from 3-D Mapping

从 3 维测绘中了解台湾弧形大陆碰撞的几何和运动学

• 批准号: 408273939
• 负责人: Privatdozentin Dr. Sara Carena
• 金额: --
• 依托单位: Department of Geoscience
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/408273939?language=en
• 关键词: Geometry; Kinematics; Taiwan; Arc; Continent

In Taiwan two subduction zones come together in a quasi-orthogonal, kinematically stable configuration. Under Taiwan the upper crust of Eurasia is largely decoupled from the rest of the lithosphere by a detachment that forms the main subduction interface between Eurasia (EU) and Philippine Sea plate (PSP). This interface is visible in both seismicity and crustal tomography at shallow depths, and can be followed into the mantle to depths of 450-500 km using global tomography. We plan to address the details of the 3-D configuration of the plates near Taiwan, focusing on the geometry and kinematics of several tectonic elements, in particular the EU/PSP plate boundary with its accretionary wedge/orogen complex, the Luzon volcanic arc, and the lithospheric-scale fold of the Eurasian lithosphere. Our goal is to determine both architecture and kinematics of the Taiwan arc-continent collision. We plan to first map in detail the 3-D geometry of the collision and reversal of subduction polarity and then place age constraints on the kinematics of the system, including changes in convergence velocity between Eurasia and Philippine Sea plate in the last 15 Ma, and show that both Eurasian lithospheric mantle and Eurasian lower crust are actively subducting below Taiwan.The outcome of this project will have a significant impact for both the local structure and tectonics of Taiwan, and for the more general plate tectonics of East Asia, as well as for the understanding of other arc-continent collision systems, past and present, which are considered as analogous to Taiwan.

在台湾，两个俯冲带以一种准正交的、运动稳定的形态聚集在一起。在台湾之下，欧亚大陆上地壳在很大程度上与岩石圈的其他部分分离，形成欧亚大陆（EU）和菲律宾海板块（PSP）之间的主要俯冲界面。在浅层地震活动和地壳层析成像中都可以看到这个界面，并且可以使用全球层析成像技术追踪到450-500公里深处的地幔。我们计划探讨台湾附近板块的三维构造细节，重点关注几个构造元素的几何和运动学，特别是EU/PSP板块边界及其增生楔/造山带复合体、吕宋火山弧和欧亚岩石圈的岩石圈尺度褶皱。我们的目标是确定台湾弧-大陆碰撞的结构和运动学。我们计划首先详细绘制碰撞和俯冲极性反转的三维几何图形，然后对该系统的运动学进行年龄约束，包括过去15 Ma欧亚大陆与菲律宾海板块之间的收敛速度变化，并表明欧亚岩石圈地幔和欧亚下地壳都在台湾下方积极俯冲。本计画的结果将对台湾的局部构造和构造，以及东亚更一般的板块构造，以及对过去和现在被认为与台湾类似的其他弧-大陆碰撞系统的理解产生重大影响。