Paleostress regimes from brittle structures of the Karakoram–Kohistan Suture Zone and surrounding areas of NW Pakistan

Paleostress orientations were calculated from fault populations at 24 sites along the SW–NE segment and five sites along the E–W, Yasin segment of the Karakoram–Kohistan Suture Zone in NW Pakistan. They demonstrate the importance of combined thrusting and strike-slip faulting. However, several paleostress tensor directions are distinguished: a dominant NW–SE compression and a minor E–W compression are compatible with the recent evolution of this part of the Hindu Kush. From the lack of both systematic overprinting-relationships and spatial trend (the two tensors were obtained at different locations) we conclude that in each location any of these two shortening directions can dominate. Heterogeneously distributed extension is found in some places and is likely due to local conditions. These paleostress tensors substantiate a transpressional regime due to far-field Himalayan compression and document the long-term background of the seismogenic deformation in this region.