Collaborative Research: How and when did the Mongolian Altai (de-)form? Implications for intracontinental deformation

合作研究：蒙古阿尔泰山是如何以及何时形成的？

• 批准号: 2111940
• 负责人: Andrea Stevens Goddard
• 金额: $ 29.49万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2111940&HistoricalAwards=false
• 关键词: Collaborative; Research; How; when; did

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). The Mongolian Altai are a ~2000 km-long mountain range in western Mongolia that are part of a vast mountainous region in central Asia referred to as the Central Asian Orogenic Belt. Understanding how a mountain system that is located 1000 km from a modern tectonic plate boundary originally formed is important as the Altai play an important role in regulating Asian climate and biodiversity and in controlling the distribution and reorganization of Earth materials through erosion and sediment transport. This study will test how the Earth’s crust deforms into mountains in the middle of tectonic plates rather than at the edges. The PIs will use thermochronology (the study of mineral cooling histories) to measure the timing of mountain development and conduct field-based studies of sedimentary rocks to study changes in erosion and deposition patterns caused by mountain uplift. These results will be compared to numerical models testing different ways to form mountains in the middle of tectonic plates. This research will provide important societal outcomes by 1) supporting the training of graduate and undergraduate students in STEM fields including minority and underrepresented students at a Hispanic Serving Institution, 2) increasing participation of women in STEM as both Principal Investigators and graduate students within this project, 3) increasing public scientific literacy through undergraduate education and education outreach, 4) developing partnerships between American and Mongolian scientists, and 5) the development of online interactive field tours for undergraduate education. Recent large-scale, interdisciplinary projects have led to major advances in our understanding of the rates, relative timing, and periodicity of tectonic plate margin processes that define orographic landscapes. However, our understanding of plate interior orogenesis is less evolved, as intracontinental orogens defy models of orogenesis as a plate-boundary driven process. The Mongolian Altai are part of one of the largest intracontinental orogenic systems–the Central Asian Orogenic Belt, and yet limited data exist to explain the origin of this mountain system. This project will test specific models of intracontinental orogenesis in the Mongolia Altai, each of which predict a different timing, rate, and style of uplift. This research will integrate bedrock and detrital thermochronology, sedimentology and basin analysis, and geomechanical modeling to document the timing of onset of intracontinental orogenesis in the Mongolian Altai; understand fundamental (rheological, geodynamic, inherited) controls on the formation of an orographic landscape in this region; and to understand the possible conditions that produce intracontinental deformation from plate boundary forces and the timescales on which this deformation occurs. These outcomes will allow testing of whether the Mongolian Altai are relict topography from a Mesozoic suture zone, are a geodynamic feature of isostatic or dynamic processes, or formed due to localized deformation from Cenozoic plate boundary stresses. Field and analytical data will provide direct observations to test these hypotheses that can be further constrained by numerical models that interrogate the geomechanical plausibility of these processes. This study will not only provide the first basement thermochronologic dataset from a ~800 km along strike zone within the Mongolian Altai and the first detrital thermochronologic dataset from the entire Altai system (2000 km strike length), but will integrate this dataset with work in contemporaneous sedimentary basins and geomechanical modeling to put these data in a well-constrained geologic context. The proposed research will also improve our understanding of what processes drive formation of intracontinental orogens globally, a major outstanding question in the field of tectonics.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.

该奖项的全部或部分资金来源于《2021 年美国救援计划法案》（公法 117-2）。 蒙古阿尔泰山是蒙古西部一条长约 2000 公里的山脉，是中部广阔山区的一部分。亚洲被称为中亚造山带，了解距离现代板块边界 1000 公里的山脉系统最初是如何形成的非常重要，因为阿尔泰山发挥着重要作用。这项研究将利用热年代学来测试地壳如何在构造板块中部而不是边缘变形为山脉。 （矿物冷却历史的研究）测量山脉发展的时间，并对沉积岩进行实地研究，以研究山脉抬升引起的侵蚀和沉积模式的变化，这些结果将与测试不同形成方式的数值模型进行比较。中间有山这项研究将通过以下方式提供重要的社会成果：1) 支持对 STEM 领域的研究生和本科生进行培训，包括西班牙裔服务机构中少数族裔和代表性不足的学生，2) 增加女性作为首席研究员和研究生的参与度该项目的学生，3）通过本科教育和教育推广提高公众科学素养，4）发展美国和蒙古科学家之间的伙伴关系，以及5）为本科教育开发在线互动实地考察最近的大型跨学科项目。导致我们对定义地形地貌的构造板块边缘过程的速率、相对时间和周期性的理解取得了重大进展，然而，我们对板块内部造山作用的理解还不够深入，因为陆内造山带违背了作为板块边界的造山作用模型。蒙古阿尔泰山是最大的陆内造山系统之一——中亚造山带的一部分，但解释该山地系统起源的数据有限。测试蒙古阿尔泰地区陆内造山作用的具体模型，每个模型都预测不同的隆起时间、速率和方式。这项研究将整合基岩和碎屑热年代学、沉积学和盆地分析以及地质力学模型，以记录发生的时间。蒙古阿尔泰地区的陆内造山作用；了解对该地区地形景观形成的基本（流变、地球动力学、继承）控制，并了解产生的可能条件；板块边界力引起的陆内变形以及这种变形发生的时间尺度，这些结果将有助于测试蒙古阿尔泰是否是中生代缝合带的遗迹地形，是均衡或动态过程的地球动力学特征，还是由于局部变形而形成。来自新生代板块边界应力的现场和分析数据将提供直接观察结果来检验这些假设，这些假设可以通过询问地质力学的数值模型进一步约束。这项研究不仅将提供蒙古阿尔泰地区沿走向地带约 800 公里的第一个基底热年代学数据集和整个阿尔泰系统（2000 公里走向长度）的第一个碎屑热年代学数据集，而且还将整合这些数据。数据集与同时期沉积盆地和地质力学建模相关，将这些数据置于严格约束的地质环境中，拟议的研究还将提高我们对驱动形成过程的理解。全球大陆内造山带是构造学领域的一个重大悬而未决的问题。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。