Thrust Belt Exhumation and Duplex Development in the Sikkim Himalaya

锡金喜马拉雅地区冲断带折返和复式开发

• 批准号: 1250475
• 负责人: Jason Barnes
• 金额: $ 22.66万
• 依托单位: University of North Carolina at Chapel Hill
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-04-01 至 2016-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1250475&HistoricalAwards=false
• 关键词: Thrust; Belt; Exhumation; Duplex; Development

Colliding tectonic plates create high uplifting landscapes that exhibit diverse spatial patterns of active deformation, affect global climate, and ultimately regulate the flux of sediment and water to the oceans. Past research shows these mountain belts grow both outward and upward in complex ways across space and time. However, major questions remain about how and why different parts of mountain belts evolve differently and what role various internal and external forcings may play in the process. Duplexes are stacks of thrust-bounded rock bodies that represent regions of intense shortening that result in focused crustal thickening and uplift rather than expansion outward. An emerging view is that a large duplex has become an important, widespread component in the frontal portion of the Himalayan chain that may be a response to concentrated monsoon precipitation and erosion. In the Sikkim Himalaya in India, the Lesser Himalayan Duplex is well exposed by river incision, the geologic structure is well documented, and hence various structural models are proposed for how it may have developed. This research project will determine the exhumation patterns of the region using bedrock cooling ages and computer models informed by the geologic structure, to quantify the integrated history of duplex deformation and exhumation. The results will determine the chronology and magnitude of Lesser Himalayan Duplex growth and erosion, address the hypothesized structural models for Lesser Himalayan Duplex development, and test the fidelity of this approach to tackling complex deformation processes throughout the world's active mountain belts and ultimately the mechanisms that drive them.This research confronts the reality that increasingly complicated deformation processes are being recognized in mountain ranges and tackles that challenge by advancing the ways we integrate geologic data and computer models to comprehend active mountain system behavior. Improved knowledge of the processes that localize mountain deformation, climate, and erosion has important implications for seismic hazards and the generation, transport, and delivery of fluid and debris to adjacent lowlands where a large portion of the Earth?s population resides. This project also represents a synergy of integrated research and education between North American and Indian geoscientists, educators, and students. Combined approaches and results from this project and a complimentary one in India will be discussed at the Indian Institute of Technology Bombay and University of North Carolina. A future US science teacher will participate in the research and translate the results into educational material for K-12 Earth Science courses and the public. This award is designated as a Global Venture Fund Award and is being co-funded by NSF?s Office of International Science and Engineering.

碰撞的构造板块创造了高隆起的景观，表现出不同的活动变形空间模式，影响全球气候，并最终调节沉积物和水流入海洋的流量。过去的研究表明，这些山脉带在空间和时间上以复杂的方式向外和向上生长。然而，主要的问题仍然是如何和为什么不同部分的山区带不同的演变和各种内部和外部的强迫可能在这个过程中发挥什么作用。复式岩是由逆冲断层包围的岩石体堆积而成，代表强烈缩短的区域，导致地壳集中增厚和隆起，而不是向外扩张。一个新的观点是，一个大的双工已成为一个重要的，广泛的组成部分，在喜马拉雅链的前部，这可能是一个集中的季风降水和侵蚀的反应。在印度的锡金喜马拉雅地区，小喜马拉雅复式岩被河流下切很好地暴露出来，地质结构被很好地记录下来，因此人们提出了各种结构模型来解释它是如何发展的。该研究项目将利用地质结构提供的基岩冷却年龄和计算机模型来确定该地区的折返模式，以量化双重变形和折返的综合历史。研究结果将确定小喜马拉雅复式结构生长和侵蚀的年代和规模，解决小喜马拉雅复式结构发展的假设结构模型，并测试这种方法的保真度，以解决整个世界的活动山区复杂的变形过程，并最终驱动他们的机制。这项研究面临的现实，越来越复杂的变形过程正在认识到在山区通过推进我们整合地质数据和计算机模型的方式来理解活跃的山脉系统行为，范围和应对这一挑战。提高认识的过程，局部山区变形，气候和侵蚀有重要的影响，地震灾害和生产，运输和交付的流体和碎片到邻近的低地，其中大部分的地球？的人口居住。该项目还代表了北美和印度地球科学家，教育工作者和学生之间的综合研究和教育的协同作用。将在孟买印度理工学院和北卡罗来纳州大学讨论这一项目的综合办法和成果以及印度的一个补充办法和成果。未来的美国科学教师将参与研究，并将结果转化为K-12地球科学课程和公众的教育材料。该奖项被指定为全球风险基金奖，并由NSF？国际科学与工程办公室。