Abstract
The Potwar Fold-and-Thrust Belt (PFTB) represents the western margin of the Himalayan Foreland Fold-and-Thrust Belt in Pakistan. This study investigates the structural evolution of a part of the northeastern PFTB through structural cross-sections constructed in 2-D and 3-D workflow, integrating the seismic section PR-92-26, structural data of surface geology, and well data from Kalar X-1. The geological formations in this region are distinguished by a wide range of rocks present at both the surface and subsurface, spanning from the Precambrian period to the Recent era. Notably, the Rawalpindi and Siwaliks groups have been exposed and are observable within the study area. The cross-sections revealed the subsurface fold geometries and kinematics of thrusts, illustrating the deformational history of the study area. The basement is identified as prominent reflector at time 4.1s or 4100ms on seismic section PR-92-26, corresponding to the depth of 9020 meters. The interpreted seismic-section demonstrate that the folded and faulted structures present in the subsurface formed as a result of back thrust and blind thrusts underlying these structures. The structural style in the northeastern PFTB is influenced by detachment folding and fault-propagation folding. A 3-D structural model was created to better understand the subsurface structural geometry, variations, and terminations of structures across the section lines. The model suggests that the regional structures extend to a depth of 9 km in the subsurface. The two deformed and restored cross-sections (AA/ and BB/) indicate that the sedimentary cover experienced approximately 29% or 6 km of shortening due to deformation.
Keywords:
Structural Kinematics, 2-D & 3-D Structural Model, Seismic Interpretation, Northeastern Potwar Basin, Crustal Shortening
