Did Channel Flow Drive the Thermo-mechanical Evolution of the Eastern Himalaya? A Field-based Test in Northeast Bhutan

河道流驱动了喜马拉雅东部的热机械演化吗？

• 批准号: 1220300
• 负责人: Stacia Gordon
• 金额: $ 39.3万
• 依托单位: Board of Regents, NSHE, obo University of Nevada, Reno
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1220300&HistoricalAwards=false
• 关键词: Did; Channel; Flow; Drive; Thermo

The Himalayan range and Tibetan Plateau represent the world?s tallest mountain range and largest area of elevated land, and are the type-example of a mountain belt that formed as a result of continent-continent collision. This system is still actively growing; therefore, study of these mountains provides a unique opportunity to understand how the crust evolves during this type of plate collision. Across much of the Himalayan range, rocks that have been buried to depths as much as approximately 35 km below Earth's surface and taken to temperatures hot enough to partially melt are observed at the surface today. These rocks have been studied in many parts of the Himalaya, and there is currently a vigorous debate over how these rocks were exhumed to the surface. The channel flow model predicts that these deeply buried rocks lost much of their strength after partially melting, and were then translated southward and towards the surface. In comparison, other proposed models argue that faults and shear zones were responsible for their exhumation, and are less focused on the driving force being the weakness of the rocks. In this project, we propose to test the applicability of these different models to rocks in the kingdom of Bhutan, which lies in the eastern part of the Himalayan range. We will do this by collecting rock samples during field expeditions, and determining the pressure, temperature, timing, and evolution of deformation that they experienced. In the past, Bhutan has been relatively isolated for geologic researchers so the majority of the rocks exposed in Bhutan have not been well studied.The results of this project will make a valuable contribution to the debate over how continental crust evolves during collisional mountain building. In addition, multiple graduate students will be trained in the field and laboratory, including one Bhutanese citizen and current employee of Bhutan's geologic survey. After he finishes his degree, he will return to Bhutan to take on a leadership role in the study of natural resources, natural hazards, and public policy. Undergraduate students will also be involved with laboratory analyses and will obtain training, education, and research experience. Finally, this study will support the research efforts of two early career researchers, as well as foster valuable international collaboration between UNR and scientists at Bhutan?s geological survey.

喜马拉雅山脉和藏族高原代表着世界上最高的山脉和高架土地的最大区域，这是由于大陆碰撞而形成的山带的类型示例。 该系统仍在积极增长。因此，对这些山脉的研究提供了一个独特的机会，可以理解这种类型的板碰撞期间的外壳如何发展。 在整个喜马拉雅山脉的大部分地区，今天的表面在地面观察到了地面表面以下约35公里的深度的岩石。 这些岩石已经在喜马拉雅山的许多地方进行了研究，目前在如何将这些岩石挖掘到表面上存在激烈的辩论。 通道流模型预测，这些深层埋葬的岩石在部分熔化后失去了许多强度，然后向南转移到表面。 相比之下，其他提出的模型认为故障和剪切区是造成其挖掘的原因，而较少专注于驱动力是岩石的弱点。 在这个项目中，我们建议测试这些不同模型对位于喜马拉雅山脉东部的不丹王国中的岩石的适用性。 我们将通过在现场探险期间收集岩石样品，并确定它们所经历的变形的压力，温度，时机和演变来做到这一点。 过去，不丹对地质研究人员相对孤立，因此不太研究不丹的大多数岩石。该项目的结果将对关于大陆地壳在碰撞山区建筑期间如何发展的辩论做出宝贵的贡献。 此外，将在野外和实验室接受多名研究生的培训，其中包括一名不丹公民和不丹地质调查员的现任雇员。 完成学位后，他将返回不丹，在自然资源，自然危害和公共政策研究中扮演领导角色。 本科生还将参与实验室分析，并获得培训，教育和研究经验。 最后，这项研究将支持两位早期职业研究人员的研究工作，并在不丹的地质调查局中促进UNR与科学家之间有价值的国际合作。