Constraining the Nature and Formation Age of the Shyok Suture Zone in Ladakh, NE India

限制印度东北部拉达克什约克缝合带的性质和形成时代

• 批准号: 1902179
• 负责人: Oliver Jagoutz
• 金额: $ 40.99万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-15 至 2023-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1902179&HistoricalAwards=false
• 关键词: Constraining; Nature; Formation; Age; Shyok

The spectacular height and length of the Himalayan Mountain Belt has inspired generations of people across the world. The mountain chain was formed during the collision of the Indian and Eurasian continents approximately 40-50 million years ago. Before this collision occurred, an ocean called the Neotethys separated the two continents and the timing of its disappearance remains an open question. This project will better constrain the timing of the collision between the two continents by age dating and paleomagnetic measurements in the Kohistan-Ladakh region of northern India. A better constraint on the timing of the collision and disappearance of the Neotethys ocean is essential not only for our understanding of the Himalayas, but also for addressing other big questions such as the how tectonic plates reorganize during major collisional events and the influence of tectonic forces on global climate.The principal goals of this project are to better constrain the nature and age of the Shyok suture zone, and to test alternative models for the Kohistan-Ladakh-Eurasia collision. If the Shyok suture is younger than the Indus suture, then the Shyok-Tsangpo suture zone, not the Indus-Tsangpo suture zone, records the final collision of India and Asia, and two subduction systems were present in the Neotethys ocean until approximately 50 Ma. We will conduct a detailed study combining field geologic mapping, petrology/geochemistry, U-Pb zircon geochronology, and paleomagnetic measurements. This work will constrain the currently unknown age and provenance of multiple sedimentary sequences in the suture zone as well as provide new information on the geochemical characteristics and ages of plutonic rocks within the suture and in neighboring terranes. Additionally, the proposed paleomagnetic work will determine the unknown paleolatitudes of both the Kohistan-Ladakh arc and Eurasian margins during the crucial time of the India-Eurasia collision and thus allow us to evaluate the different collision scenarios. The work related to this project constitutes a comprehensive and multifaceted documentation of a pivotal yet unconstrained suture zone in the Himalaya and offers the opportunity to capitalize on the recently increased access to crucial exposures in Ladakh, India.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

喜马拉雅山脉壮观的高度和长度激励着世界各地几代人。 这条山脉是在大约 40-5000 万年前印度大陆和欧亚大陆碰撞期间形成的。 在这次碰撞发生之前，一个名为新特提斯洋的海洋将两个大陆分开，其消失的时间仍然是一个悬而未决的问题。该项目将通过印度北部科希斯坦-拉达克地区的年代测定和古地磁测量，更好地确定两大洲碰撞的时间。 更好地限制新特提斯海洋碰撞和消失的时间不仅对于我们了解喜马拉雅山至关重要，而且对于解决其他重大问题，例如重大碰撞事件期间构造板块如何重组以及构造力对全球气候的影响。该项目的主要目标是更好地限制什约克缝合带的性质和年龄，并测试新特提斯缝合带的替代模型。 科希斯坦-拉达克-欧亚大陆碰撞。如果什约克缝合带比印度河缝合带更年轻，那么记录印度和亚洲最终碰撞的是什约克缝合带，而不是印度河-雅鲁藏布缝合带，新特提斯洋中直到大约50 Ma才出现两个俯冲系统。 我们将结合野外地质测绘、岩石学/地球化学、U-Pb 锆石地质年代学和古地磁测量进行详细研究。这项工作将限制目前未知的缝合带内多个沉积序列的年龄和来源，并提供有关缝合带内和邻近地体中的深成岩的地球化学特征和年龄的新信息。此外，拟议的古地磁工作将确定印度-欧亚大陆碰撞关键时期科希斯坦-拉达克弧和欧亚边缘的未知古纬度，从而使我们能够评估不同的碰撞场景。与该项目相关的工作构成了对喜马拉雅山一个关键但不受限制的缝合带的全面、多方面的记录，并提供了利用最近增加的印度拉达克关键暴露的机会。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。