Collaborative Research: How does it end? Exploring thrust terminations of an intra-continental strike-slip fault, north Tibet

合作研究：它如何结束？

• 批准号: 1914503
• 负责人: Peter Haproff
• 金额: $ 4.08万
• 依托单位: University of North Carolina at Wilmington
• 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: 2019-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1914503&HistoricalAwards=false
• 关键词: Collaborative; Research; How; does; end

Plate tectonic theory suggests that internally rigid tectonic plates interact with one another along narrow plate boundaries. However, deformation is often distributed across the interior of continents, such as in the Asian continent along the Himalayan mountain belt, where significant faulting and folding occurs thousands of kilometers from the boundaries between the Indian and Pacific plates. Some of the largest features in the region are east-west oriented strike-slip faults, such as the Haiyuan fault in north Tibet. This project investigates the western termination of the Haiyuan fault to determine how deformation changes from strike-slip fault motion to folding and thrust faulting within the interior of the mountain belt. Furthermore, structures like the Haiyuan fault are sources of major seismic hazards for densely-populated regions within the Asian continent. Thus, constraining the style, magnitude, and rate of deformation along the length of these strike-slip faults will aid in future hazard and risk assessment. Other societally relevant impacts of this project include: support of early-career faculty to establish globally competitive research programs; training a PhD student and mentoring two undergraduates in a science, technology, engineering and mathematics (STEM) discipline; international collaboration with researchers and institutions; and outreach at community engagement events with a focus on earthquake hazards. The project also supports the development of a modern publicly-accessible geologic mapping website that features techniques and information about digital tablet-based field mapping and digital elevation model (DEM) construction, including methods of incorporating map data into open-access online archives.The intra-continental response to edge-driven plate boundary conditions is a central topic in continental tectonics. The Himalayan-Tibetan orogen results from progressive Cenozoic India-Asia convergence, and the largest structures within the interior of this orogen are large strike-slip faults. Therefore, Tibet is an ideal testing ground to determine how strike-slip faulting accommodates and redistributes strain in a collisional orogen. This multidisciplinary investigation explores the western termination of the left-slip Haiyuan fault within northern Tibet, where strike-slip faulting abruptly transitions to thrust faulting. Specifically, a combination of geologic bedrock and neotectonics mapping, construction of digital elevation models (DEMs) using structure-from-motion (SfM) methods, surface-age dating (i.e., optically stimulated luminescence and radiocarbon), and low-temperature thermochronology are employed to (1) constrain Quaternary slip rates along the western Haiyuan fault segments, and (2) systematically document how strike-slip deformation transfers to a range-bounding, thrust-fault system in the central Qilian Shan thrust belt. Field observations of the kinematics of the western termination of the Haiyuan fault are used to test models for plate-convergence-normal strike-slip faulting in the Himalayan-Tibetan orogen, including (1) clockwise-fault rotation, (2) extrusion-fault models, and (3) strain transfer models. Insights gained from studying the Haiyuan fault can be applied to other zones of intra-continental deformation.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.

板块构造理论表明，内部刚性的构造板块沿着狭窄的板块边界相互作用。然而，变形往往分布在大陆内部，例如沿着喜马拉雅山带的亚洲大陆，在距离印度板块和太平洋板块边界数千公里的地方，发生了严重的断层和褶皱。该地区一些最大的特征是东西向的走滑断层，例如藏北的海原断层。该项目调查海原断层的西端，以确定山地带内部的变形如何从走滑断层运动转变为褶皱和逆冲断层。此外，像海原断层这样的构造是亚洲大陆人口稠密地区的主要地震灾害源。因此，限制沿着这些走滑断层长度的变形类型、大小和速率将有助于未来的灾害和风险评估。该项目的其他社会相关影响包括： 支持早期职业教师建立具有全球竞争力的研究项目；培养一名博士生并指导两名科学、技术、工程和数学（STEM）学科的本科生；与研究人员和机构的国际合作；并在以地震灾害为重点的社区参与活动中进行外展活动。该项目还支持开发一个现代的可公开访问的地质测绘网站，该网站提供有关基于数字平板电脑的现场测绘和数字高程模型（DEM）构建的技术和信息，包括将地图数据纳入开放访问在线档案的方法。大陆内部对边缘驱动板块边界条件的响应是大陆构造学的中心主题。喜马拉雅-青藏造山带是新生代印度-亚洲渐进聚合的结果，该造山带内部最大的构造是大型走滑断层。因此，西藏是确定走滑断层如何适应和重新分布碰撞造山带应变的理想试验场。这项多学科研究探索了藏北左滑海原断层的西端终点，这里走滑断层突然转变为逆冲断层。具体来说，结合了地质基岩和新构造测绘、使用运动结构（SfM）方法构建数字高程模型（DEM）、表面年龄测年（即光激发光和放射性碳）以及低温热年代学。用于（1）约束海原断层西部沿第四纪的滑动速率，以及（2）系统地记录走滑变形如何转移到范围限制的逆冲断层系统位于祁连山冲断带中部。利用海原断裂西端运动学的现场观测，检验了喜马拉雅-青藏造山带板块汇聚-正走滑断裂模型，包括（1）顺时针断裂旋转，（2）挤压断裂模型，以及（3）应变传递模型。从海原断层研究中获得的见解可以应用于大陆内变形的其他区域。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。

项目成果

Paleoproterozoic Plate Tectonics Recorded in the Northern Margin Orogen, North China Craton

• DOI: 10.1029/2022gc010662
• 发表时间: 2022-11
• 期刊: Geochemistry
• 影响因子: 3.7
• 作者: Chen Wu;Guosheng Wang;Zhiguang Zhou;P. Haproff;A. Zuza;Wenyou Liu

Kinematic evolution of a continental collision: Constraining the Himalayan-Tibetan orogen via bulk strain rates

• DOI: 10.1016/j.tecto.2020.228642
• 发表时间: 2020-12
• 期刊: Tectonophysics
• 影响因子: 2.9
• 作者: A. Zuza;Y. Gavillot;P. Haproff;Chen Wu

Accommodation of India–Asia convergence via strike-slip faulting and block rotation in the Qilian Shan fold–thrust belt, northern margin of the Tibetan Plateau

• DOI: 10.1144/jgs2020-207
• 发表时间: 2021-01
• 期刊: Journal of the Geological Society
• 影响因子: 2.7
• 作者: F. Cheng;A. Zuza;P. Haproff;Chen Wu;C. Neudorf;Hong Chang;Xiangzhong Li;Bing Li

Cenozoic kinematic histories of the Tidding and Lohit thrusts in the northern Indo-Burma Ranges: Implications for crustal thickening and exhumation of Gangdese lower arc crust along the Indus-Yarlung suture zone

印缅山脉北部蒂丁和洛希特逆冲断层的新生代运动史：印度河-雅鲁藏布江缝合带冈底斯下弧地壳增厚和折返的意义

• DOI: 10.1130/b36323.1
• 发表时间: 2022
• 期刊: GSA Bulletin
• 作者: Haproff, Peter J.;Levy, Drew A.;Zuza, Andrew V.;Hooker, Julian D.;Heizler, Matthew T.;Stockli, Daniel F.;Braza, Mary
• 通讯作者: Braza, Mary

Tectonic setting of metamorphism and exhumation of eclogite-facies rocks in the South Beishan orogen, northwestern China

北山南造山带榴辉岩相岩石变质作用与折返作用的构造背景

• DOI: 10.1130/ges02548.1
• 发表时间: 2022
• 期刊: Geosphere
• 影响因子: 2.5
• 作者: Li, Jie;Wu, Chen;Chen, Xuanhua;Yin, An;Zuza, Andrew V.;Haproff, Peter J.;Chen, Yanfei;Wang, Luojuan;Shao, Zhaogang
• 通讯作者: Shao, Zhaogang