Thrusting and Strike-slip Faulting along the Western Boundary of Indo-Pakistan Plate

Abstract

  Along western boundary of the Indo-Pakistan plate a system of Riedel Rand R(shears is expected to develop due to a dominant component of simple shear. The majority of strike-slip faults trend between N-S and NNW-SSE, close to the expected orientation of R shears. A few strike almost parallel to the expected orientation of R’ shears Faults close to R shears show dextral sense of displacement. Both the orientation and sense of displacement suggest that majority of these strike-slip faults are secondary Riedel shears, developed in response to a plate scale sinistral simple shear, along the Chaman transform fault. With the exception of Sulaiman Lobe, thrusts along the western boundary of Indo-Pakistan plate generally trend N-S. Palaeomagnetic studies suggest that E-W oriented thrusts of Sulaiman Lobe may be result of a later clock-wise rotation. The general N-Strend of these thrusts is almost parallel to the orientation of plate boundary and suggests that they may be part of a positive flower structure developed in response to regional sinistral transpression along the transform plate boundary.