Extensional Fault Systems in the Ama Drime Range, Southern Tibet

藏南阿妈岭山脉的伸展断层系统

• 批准号: 0711140
• 负责人: Kip Hodges
• 金额: --
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0711140&HistoricalAwards=false
• 关键词: Extensional; Fault; Systems; Ama; Drime

Recent research on the Himalayan-Tibetan orogenic system has focused on the role of monsoon climate in its development. In one controversial hypothesis, aggressive monsoon precipitation currently attracts the southward flow of a channel of middle crust from beneath the Tibetan Plateau to the Himalayan orogenic front. In this project, an Arizona State University research team, in collaboration with scientists from the Chinese Academy of Sciences, is testing the prediction that a recently active detachment occurs along the southern edge of the Tibetan Plateau at the approximate position of the Miocene South Tibetan fault system in the Ama Drime Range of southern Tibet. This transverse range has the overall form of a metamorphic core complex and is bound on the east and west by normal fault systems that strike directly into previously mapped strands of the South Tibetan fault system. The team is mapping critical intersections among these fault systems that are spectacularly exposed in this high-elevation region within the Himalayan rain shadow. They are also using the techniques of structural geology, tectonic geomorphology, low-temperature thermochronology, and cosmogenic nuclide dating to establish the late Cenozoic exhumation history of the Ama Drime massif and compare it with the exhumation history of the South Tibetan fault footwall east and west of the massif. These results will be used to evaluate the case for Quaternary channel extrusion and either falsify it or establish the structural and geomorphic consequences of deformation related to the upper bounding structure of the extruding channel.The concept of channel flow is a new and controversial idea in the field of tectonics. It suggests a strong coupling between climate and tectonics. The original version of the channel flow-extrusion hypothesis envisioned that Early-Middle Miocene southward extrusion of the channel was accommodated by slip on two north-dipping structures: the Main Central thrust and the South Tibetan fault systems. This study explores that idea that monsoon-induced channel flow continues today. The results of this work will be central to the ongoing debate over the style of deformation and the degree of erosion and tectonics coupling in the Himalaya.

关于喜马拉雅藏雕质系统的最新研究集中在季风气候在其发展中的作用上。在一个有争议的假设中，侵略性的季风降水目前吸引了从藏族高原下方到喜马拉雅造影界的中层地壳通道的南流动。在这个项目中，亚利桑那州立大学研究团队与中国科学院的科学家合作，正在测试以下预测：最近在藏族高原的南部边缘发生了最近在藏族南部藏族断层位置的近距离脱离西藏南部的AMA DILIME系列中的系统。该横向范围具有变质核心复合物的整体形式，并通过正常断层系统在东方和西部结合，该系统直接撞向了南藏断层系统的先前映射的链。该团队正在这些断层系统中绘制关键交叉路口，这些系统在喜马拉雅雨影片内的高海拔地区露面。他们还使用结构地质学，构造地貌，低温热量学和宇宙核素约会的技术来建立ama drime massif的周期库诺卡灌肠纪录，并将其与南藏东部东部和西部的灌输历史进行比较地块。这些结果将用于评估第四纪通道挤出的案例，并伪造它或建立与挤出通道上限结构相关的变形的结构和地貌后果。通道流的概念是一种新的且有争议的思想。构造领域。它表明气候和构造之间有很强的耦合。通道流排除假设的原始版本设想，在两个北倾式结构上滑倒可以容纳通道的早期中新世向南挤出：主要中央推力和南藏族断层系统。这项研究探讨了今天季风引起的通道流动今天仍在继续的想法。这项工作的结果将是关于喜马拉雅山中的变形风格以及侵蚀程度以及侵蚀程度的持续辩论。