Strike-slip faulting in a foreland fold-thrust belt: The Kalabagh Fault and Western Salt Range, Pakistan
Article first published online: 26 JUL 2010
Copyright 1990 by the American Geophysical Union.
Volume 9, Issue 5, pages 1061–1075, October 1990
How to Cite
1990), Strike-slip faulting in a foreland fold-thrust belt: The Kalabagh Fault and Western Salt Range, Pakistan, Tectonics, 9(5), 1061–1075, doi:10.1029/TC009i005p01061., and (
- Issue published online: 26 JUL 2010
- Article first published online: 26 JUL 2010
- Manuscript Accepted: 9 FEB 1990
- Manuscript Received: 14 JUL 1988
The 120-km-long Kalabagh fault zone is formed by transpressive right-lateral strike-slip along the western Salt Range-Potwar Plateau allochthon in northern Pakistan. Lateral ramping from a decollement thrust along an Eocambrian evaporite layer produced NNW- to NW-trending folds and NE- to N-dipping thrust faults in a topographically emergent zone up to 10 km wide. Piercing points along the main Kalabagh fault indicate 12–14 km of middle to late Quaternary right-lateral offset. The older right-lateral Surghar fault displaced axes of frontal folds of the eastern Surghar Range by 4–5 km. Total displacement is reduced northward in the Kalabagh fault zone where north-dipping thrust faults splay to the west. Cumulative right-slip offset in the Kalabagh fault zone is comparable to displacement along the Salt Range frontal thrust, at a minimum average displacement rate of 7–10 mm/year near the Indus River since 2 Ma. In the basement, which dips 2–3° north along the Kalabagh fault, a NNW-trending discontinuous ridge beneath the lateral ramp is interpreted from residual gravity anomalies. The eastern flank of this basement ridge probably ramped allochthonous strata upward from a depth of over 5 km in the Kalabagh fault zone. Kalabagh faulting displaced and uplifted Holocene terrace deposits and shifted the course of the Indus River eastward. A high slip rate and associated seismicity indicate that the Kalabagh fault zone should be considered active and capable of earthquakes.