Seismicity and landform development of the dextral Kalabagh Fault Zone, Pakistan: Implications from morphotectonics and paleoseismology

• Published in: Tectonophysics Vol. 822; p. 229182
• Main Authors: Abbas, Wahid, Ali, Sajid, Reicherter, Klaus
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 05.01.2022; Elsevier BV
• Subjects: Alluvial deposits; Alluvial fans; Bends; Earthquakes; Fault zones; Fluvial sedimentation; Fluvial sediments; Fronts; Geological faults; GPR; Kalabagh fault; Landforms; Morphotectonics; Mountains; Pakistan; Paleogeology; Paleoseismology; Quaternary; Ridges; Rivers; Sediment; Sediments; Segments; Seismic activity; Seismicity; Seismology; Stratigraphy; Tectonic landscape evolution; Tectonics; Uplift; Indus River; Pakistan; GPR; Pakistan; Tectonic landscape evolution; Paleoseismology; Kalabagh fault; Morphotectonics
• ISSN: 0040-1951; 1879-3266
• DOI: 10.1016/j.tecto.2021.229182

The Kalabagh Fault Zone in the western Sub-Himalayas is a dextral strike slip fault zone that exhibits a push-up block in the stepover zone of the two fault segments. The inception of the push-up block occurred along the restraining faults that form two morphotectonic bends along the mountain front at Zaluch and in the South of Thathi. The landform was further developed by en-echelon fold and thrust sequence up to Khairabad in the North and Ghundi village in the South. The aseismically moving fault zone has experienced earthquakes during late Quaternary forming surface expressions in the West of the push-up block at Khairabad, Larkakki and Ghundi. The Khairabad and Ghundi sections are the active tectonic fronts of the stepover zone. Displacements caused by these seismic activities has deformed Quaternary sediments creating stream deflections, surface ruptures, pressure ridges, uplifted sediments at the mountain front, foreland ridges and uplifted alluvial fan. Offsets in the late Quaternary sediments indicate the Kalabagh Fault is active and seismic events of Mw ≥ 6 has formed these ground effects. Furthermore, stratigraphic correlations of fluvial sediments indicate the Indus River has been flowing in the NS direction along the northern segment of the Kalabagh Fault. Uplift of the push-up block in the Kalabagh Fault Zone and subsequent deposition of the alluvial fans has caused westward diversion of the Indus River.