Gravity Survey and Lithospheric Structure Across the Altyn Tagh

9706388麦克纳特大陆构造的突出问题之一是大陆走滑断裂的深部结构。通过简单的海洋类比，它们可能是垂直的断层面，切割了整个岩石圈，并为漂移的板块之间的应变提供了尖锐的焦点。另一方面，它们可能会进入下地壳的倾斜分离带，使地表地质和大地测量图上的运动与地幔岩石圈更深的运动脱钩。为了区分这两个末端成员模型，PI将对阿尔金山塔格的两个长断面进行重力测量，阿尔金塔格是一条主要的大陆走滑断层，将青藏高原与位于中国西南部的塔里木盆地隔开。横跨这条断层的大地形起伏使它成为使用非常简单的重力技术来确定阿尔金塔格是否切割地幔岩石圈以及断层上的应力状态的理想地点。***

9706388 McNutt One of the outstanding problems in continental tectonics is the deep structure of continental strike-slip faults. By simple oceanic analogy, they might be vertical fault planes cutting the entire lithosphere and providing a sharp focus for strain between drifting plates. On the other hand, they may sole out into dipping detachments in the lower crust that decouple the motions mapped from surface geology and geodesy from those in the deeper mantle lithosphere. To distinguish between these two end-member models, the PI will conduct a gravity survey of two long transects across the Altyn Tagh, a major continental strike-slip fault separating the Tibet Plateau from the Tarim Basin in southwestern China. The large topographic relief across this fault makes it the ideal place to use very simple gravimetric techniques to determine whether or not the Altyn Tagh cuts the mantle lithosphere and what is the state of stress on the fault. ***