摘要
Microscopic to mesoscopic structural investigations and foliation intersection axes(FIAs) preserved in porphyroblasts reveal a very complex history of deformation and tectonism within the southwestern part of the western hinterland zone along the northern margin of the Indian plate, NW Pakistan. D_1, D_2, and D_3 related structures in the southwestern part resemble the F_1/F_2, F_3, and F_4 related structures in the northeastern part of the western hinterland zone. These structures developed at the same time through the same changes in the direction of bulk shortening in southwestern and northeastern parts of the western hinterland zone. FIA set 1 indicates NW-SE shortening. The D_2 fabrics, mineral lineations and fold axes indicate E-W shortening. FIA set 2, D_3 fold axes and mineral lineations indicate NNE-SSW shortening. D_3 deformation event is equivalent to the F_4 deformation event in the northeastern part of the western hinterland zone. D_4 fold axes, mineral stretching lineations and axial plane foliation suggest ENE-WSW shortening. The D_4 NNW-SSE fabrics, which formed in the region after the formation of the MMT(main mantle thrust), Khairabad-Panjal thrust fault, Hissartang thrust fault and MBT(main boundary thrust), likely resulted from ENE-WSW bulk shortening related to development of the Hazara-Kashmir syntaxis.
Microscopic to mesoscopic structural investigations and foliation intersection axes(FIAs) preserved in porphyroblasts reveal a very complex history of deformation and tectonism within the southwestern part of the western hinterland zone along the northern margin of the Indian plate, NW Pakistan. D_1, D_2, and D_3 related structures in the southwestern part resemble the F_1/F_2, F_3, and F_4 related structures in the northeastern part of the western hinterland zone. These structures developed at the same time through the same changes in the direction of bulk shortening in southwestern and northeastern parts of the western hinterland zone. FIA set 1 indicates NW-SE shortening. The D_2 fabrics, mineral lineations and fold axes indicate E-W shortening. FIA set 2, D_3 fold axes and mineral lineations indicate NNE-SSW shortening. D_3 deformation event is equivalent to the F_4 deformation event in the northeastern part of the western hinterland zone. D_4 fold axes, mineral stretching lineations and axial plane foliation suggest ENE-WSW shortening. The D_4 NNW-SSE fabrics, which formed in the region after the formation of the MMT(main mantle thrust), Khairabad-Panjal thrust fault, Hissartang thrust fault and MBT(main boundary thrust), likely resulted from ENE-WSW bulk shortening related to development of the Hazara-Kashmir syntaxis.
基金
the National Centre of Excellence in Geology, University of Peshawar for providing funds and logistical support during this research