Tectonic geomorphology and structural architecture of eastern Sulaiman Fold Thrust Belt (SFTB) and adjacent Sulaiman Foredeep (SF), northwest Pakistan

Abstract

This investigation combines a number of datasets to provide an enhanced and improved tectono-geomorphological framework with which to identify new possible structural lineaments in northwest Pakistan. The dataset includes satellite images and geographic information system (GIS) methods. The present study was carried out using the USGS ASTER DEM (30 m), Landsat 8 (OLI/TIRS) and surface field geology of the study area. Different band combinations, directional filters and principle component analysis (PCA) methods were used to identify the major structural styles and tectonic geomorphological pattern. The panchromatic band (Band-8) was applied to the Landsat 8 satellite images in order to increase the spatial resolution from 30 m to 15 m which aided in the investigation and comparative analysis of tectonic geomorphology and structural styles. Drainage patterns of Zindapir Anticline (ZA), Sakhi Sarwar (SS), Sulaiman Foredeep (SF) and Kingri Fault (KF) areas were generated using Strahler order of streams. The results suggested a combination of the dendritic network with a minor component of trellis pattern for ZP and SF areas, hence proposing a combined structural and stratigraphic/lithological control, whereas the KF area indicated an element of a rectangular pattern suggesting a more structural influence in the western part in comparison to the eastern region. The presence of water gaps (WaGs) and active drainage network indicate lateral growth and propagation directions of the ZP and SS frontal anticlines following the Paleocene Epoch. The geomorphic evidence coupled with satellite data show that the SFTB is tectonically active along with the adjacent SF. The stream courses are deflected or guided due to active folds and tectonics in the area characterized by the distinct fluvial erosional pattern on the flanks/limbs of ZA. Evidence from the study suggests that compressional deformation, uplift and erosion played a significant role in the shaping of the structural and depositional architecture of the basin. It is proposed that the deformation in the SFTB during the late Paleogene is related to the Indian-Eurasian oblique collision, while the subsequent late Tertiary collision of Indian Plate with the Afghan Block (an accreted part of southern Eurasia) further ensued compressive deformation. The results from this study elucidate the possible models proposed for this compressional regime with prevailing wrenching by presenting new data. The findings from this research reveal new tectono-geomorphological features and lineaments in the area that were not documented previously.