Geology and Tectonic of the Sulaiman Fold Belt, Pakistan

Abstract

Geology and Tectonic of the Sulaiman Fold Belt, Pakistan Ishtiaq Ahmed Khan Jadoon and Muhammad Owais Zeb COMSATS University Islamabad, Abbottabad Campus Abstract The Sulaiman Fold belt (SFB) represents a prolific petroleum province of Pakistan at the western edge of the Indian plate. It is either sporadically mapped or mapped on a very coarse scale. We have produced a revised tectonic map of the fold belt on 1:500,000 scale synthesizing all available surface (geological maps) and subsurface (seismic and borehole) information combined with satellite data and reconnaissance field work. Mapping is carried out with eleven (11) tectonostratigraphic layers representing Permo-Triassic platform to Neogene clastic strata, with consideration of competent and incompetent units, one (1) structural layer for folds, faults and fractures and one (1) geomorphic layer for drainage system, roads and settlements. The map depicts the updated geology of the entire region with pattern of folding and faulting along three structural cross-sections across the western, central and eastern SFB. Generally, Neogene clastic strata are exposed, with absence of thrust faults and dominance of brittle deformation, in the foreland. Whereas, older strata are consistently exposed, with dominance of brittle/ductile deformation, in the internal part of the system. Folds reflects zones of salient and recesses with presence of structural culminations and depressions. Both, duplex and imbricate structures are interpreted. Kingri and Khalifat-Harnai fault zones are recognized as lateral ramps in the lobate fold belt. The trend of the folds swings towards NE-SW and NW-SE along the eastern and western margin of the fold belt respectively, due to drag along the edge of thrust system. Thrust sheets depict variable geometrical arrangements as isolated, diverging, connecting and rejoining splays. Mega fractures are analyzed based on image analysis for their occurrence and orientation. All sets of fractures are interpreted, with dominance of tensional set with stress variation across the region. Orientation of maximum stress based on both trends of folds and fractures is consistent with thrust fault focal-mechanism solutions of earthquakes and resultant stress tensors. The geological map, with cross-sections and updated inventory of boreholes, serves as a significant contribution for hydrocarbon exploration in a frontier petroleum province of Pakistan.

AAPG Datapages/Search and Discovery Article #90350 © 2019 AAPG Annual Convention and Exhibition, San Antonio, Texas, May 19-22, 2019