Relationship Between E-W Extension and N-S Shortening in the Himalayas and Tibet

9706216 Hodges印度-亚洲碰撞带是大陆-大陆碰撞的典型区域，对该碰撞带的研究揭示了这种碰撞的构造过程，这在更古老的碰撞系统中是无法得到的。最近工作结果的一个特别令人困惑的特征是，西藏喜马拉雅山脉的北部似乎主要表现为东西向伸展和地堑填充，而该造山带的南部似乎反映了N-S缩短和最近的发掘。允许这种关系存在的结构和构造过程尚不为人所知，这是本项目的主题。他们将利用构造地貌学来研究这一地区的地质，进行活动断层分析，并利用沉积学、地层学、古地磁来分析沉积物填充地堑。如果研究成功，他们将能够验证仅靠藏南拆离体系的位移是否可以解释这种由压缩到伸展的南向北转变，以及是否可以约束地形隆升的时间。这反过来又将允许进一步测试这种地形与晚新生代气候演化的关系。

9706216 Hodges The Indian-Asian collision zone is the type locality of a continent-continent collision, and studies of this zone reveal the tectonic processes of such collisions that are not obtainable in more ancient collision systems. One particularly confounding feature of results of recent work is that the northern portion of the Tibetan Himalayan range seems to display mostly E-W extension and graben filling, while the southern part of this orogen seems to reflect N-S shortening and recent exhumation. The structural and tectonic processes that allow this relationship to exist are not well known, and are the subject of this project. They will investigate the geology of this region using tectonic geomorphology, for active fault analysis, and sedimentology, stratigraphy, paleomagnetism for the analysis of sediments filling grabens. If they are successful, they will be able to test whether displacement on the south Tibet detachment system alone can explain this south to north transition from compression and extension, as well as constrain the timing of the uplift of the topography. This in turn will allow further testing of the relationship of this topography to climate evolution in the late Cenozoic.