Fault-creep or Strain-accumulation on Flat Surfaces of Decollement? A GPS Study on the Salt Range and Potwar Plateau of Pakistan

巴基斯坦的波特瓦尔高原是一个5-10公里厚的岩石组合，这些岩石的年龄都不到4.5亿年，它们正以大约10毫米/年的速度被构造力推到富盐滑脱带上向南移动。调查试图确定无地震蠕变是否是这个150公里x150公里省份平移过程的重要组成部分，或者高原是否部分或完全锁定，并在地震期间滑动。全球定位(GPS)方法被用来检查形变过程，既作为1850年安装的殖民地三角点的位移，也作为新安装的大地标志的年运动。如果高原目前被锁定，将对该地区的地震灾害产生重要后果。如果它正在迅速爬行，这将对高原的构造形成和变形产生重要影响，高原是一个盛产石油的地区。波特瓦尔高原是地球历史上记录在案的众多地质滑脱的代表，它目前的运动学行为可以限制它们内部发生的变形类型。

The Potwar Plateau in Pakistan is a 5-10 km thick assemblage of rocks all younger than 450 million years that are being driven southward over a salt-rich decollement by tectonic forces at approximately 10 mm/year. The investigations are seeking to establish whether aseismic creep is a significant component of the translation process of this 150 km x150 km province, or whether the Plateau is locked, partly or completely, and slips during earthquakes. Global Positioning (GPS) methods are used to examine the deformation process, both as displacements of colonial trigonometrical points installed in 1850, and as annual motions of newly installed geodetic markers. If the Plateau is currently locked it will have important consequences for earthquake hazards in the region. If it is creeping rapidly this will have important implications for the structural formation and deformation of the Plateau, a region steeped with oil reservoirs. The Potwar Plateau is representative of numerous geologic decollements documented in earth's history, and its present kinematic behavior can place bounds on the types of deformation that have occurred within them.