Digital elevation model-based lineament analysis of the Zindapir anticline, Sulaiman fold-and-thrust belt, Pakistan

Abstract

The N-S oriented Zindapir anticline is an eastward verging mega-structure (~130 km along and ~40 km across the strike) in the eastern Sulaiman fold-and-thrust belt on the western margin of the Indian Plate in Pakistan. In this study, we carried out a lineament analysis of the anticline based on shuttle radar topographic mission (SRTM) images and digital elevation model (DEM) data to demonstrate the application of this technique for modelling of the fractured reservoirs. We used shaded relief images, variations in the vertical exaggeration, sun and azimuth angles to enhance the DEM data and structures in the area. Stereographic projections indicated that the anticline is an upright, asymmetrical, gentle, doubly plunging and east-vergent fold. The synthesized lineament map of the fractures indicates a total of 402 fractures across the Zindapir anticline. A total of 204 and 198 fractures were observed in the eastern and western limbs, respectively. Statistical analysis portrayed that the lineaments of the majority of fractures followed northwest-southeast (NW-SE) and west-northwest—east-southeast (WNW-ESE) trends. These are oblique or transverse to the fold axis and could be interpreted as shear and tensional fractures related to drag and compression along the western boundary of the Indian Plate. Our study provides an example of lineament analysis for structural characterization and modelling of fractured reservoirs in a collision-mountain setting.