Document Type : Research Paper
Institute of Geology, University of the Punjab, Lahore 54590, Pakistan
The research is based on the numerical study of late Cenozoic compressional events of NW Himalayas, Pakistan. The study area lies in Potwar Basin and southern Hazara Basin bounded by north dipping Salt Range Thrust (SRT) and Panjal Thrust (PT) in south and north respectively. Four major thrusts i.e. Panjal Thrust (PT), Nathia Gali Thrust (NGT), Main Boundary Thrust (MBT) and Salt Range Thrust (SRT) are considered as major discontinuities in the study area. The main objective is to observe maximum principle stress (σ1) rotation along major discontinuities and to calculate total deformation. For this purpose, 2D finite element method (FEM) technique has been adopted and Ansys Workbench 19.2 is used, which provides the facility to simulate stress along major thrusts. Material properties i.e. density (2.5 - 2.75), Young’s Modulus (70GPa, 100GPa) and Poisson’s ratio (0.25) are used to calculate the possible results. Pressure (60MPa) is applied from north and remaining sides of geometry kept fixed. The results obtained show that the direction of maximum principle stress (σ1) is N-S but also rotates at discontinuities at different angles. At some segments along of major thrusts σ1 rotates 40-45 degree and at some points it becomes parallel to the fault plane. These rotations of σ1 are due to the change in material properties and fault angles. Strike slip movement has also been found along some segments of major thrusts.