Evolution of Drainage in Response to Brittle - Ductile Dynamics and Surface Processes in Kachchh Rift Basin, Western India

Abstract

The eastern part of Kachchh Rift basin was reactivated after 2001 Bhuj earthquake of Mw 7.7 and continuous seismicity has been recorded since then. The northern part of Wagad upland also experienced moderate earthquakes Mw ≥ 5.7 in February 2006 and March 2007. These moderate to major Intraplate earthquakes provide a unique opportunity to study the effects and linkage between brittle-ductile dynamics, surface processes and drainage evolution. We presented a geomorphological analysis of the Wagad highland providing new constraints on the evolution of river network. The shallow to deeper nature of fault and their response to development of hydrological networks has been analyzed using seismic tomography. Based on surface drainage offset and seismic structures several E-W oriented faults controlling fluvial dynamics are identified. From seismic structures and drainage offset it is clear that the fluvial dynamics is controlled by shallower to deeper faults. The estimated attributes are well supported with seismic structures and focal mechanisms solutions. Based on fluvial offset and seismic structure analysis a new tectonic model has been proposed for WH. The tectonic model shows that the faults WH are well connected at deeper level and generated negative flower structures and significantly controlling surface fluvial dynamics.

GPS and InSAR derived evidences of intra‐basin stress and strike‐slip tectonics in the vicinity of 2001 (M7.7) earthquake, Kachchh, western India

“…Our geodetic results-based model strongly identified strike-slip motion in the middle of the Kachchh Rift Basin. These results are well-corroborated with the geological observations of strikeslip wrench geometry proposed by Kothyari et al (2018), where several fault branches are interacting together and generating a significant amount of stress within the PDZ. Furthermore, the geological and geodetic models together suggest that the strike-slip wrench faults in the Kachchh Basin are primarily responsible for the generation of presentday seismicity in the Kachchh.…”

“…The relocated earthquake events of 2006-2014 indicate dominant strike-slip motion with normal and reverse components occurred in the zone of SWF and GF (Figure 7) (Kothyari et al, 2017;Singh et al, 2016). This observation is supported by the presence of negative flower structure and occurrence of dominant strike-slip motion-related earthquakes with normal fault component in the GF zone (Kothyari et al, 2018).…”

“…The KRB evolved by rifting along the two major shoulder faults, North Kathiawar Fault (NKF) and Nagar Parker Fault (NPF), during the Mesozoic era (Biswas, 1987(Biswas, , 2005 and transformed as a compressive regime postcollision of India-Eurasia Plate (Biswas, 2005;Biswas & Deshpande, 1970;Rastogi et al, 2012). Tectonically, the KRB constitute Island Belt Fault (IBF), Gedi Fault (GF), North Wagad Fault (NWF), South Wagad Fault (SWF), Kachchh Mainland Fault (KMF), Katrol Hill Fault (KHF), Vigodi Fault (VF), Gora Dungar Fault (GDF) in between the NKF to NPF and most of them are E-W trending (Biswas, 1987(Biswas, , 1993(Biswas, , 2005Kothyari et al, 2018) (Figure 1). The zone located in the vicinity of 2001 (M7.7) event reveals enhanced strain and seismicity in the KRB and indicates the active nature of faults in the central-eastern KRB (Dumka et al, 2019;Dumka & Rastogi, 2013;Kothyari et al, 2018;Suribabu et al, 2022).…”

“…Tectonically, the KRB constitute Island Belt Fault (IBF), Gedi Fault (GF), North Wagad Fault (NWF), South Wagad Fault (SWF), Kachchh Mainland Fault (KMF), Katrol Hill Fault (KHF), Vigodi Fault (VF), Gora Dungar Fault (GDF) in between the NKF to NPF and most of them are E-W trending (Biswas, 1987(Biswas, , 1993(Biswas, , 2005Kothyari et al, 2018) (Figure 1). The zone located in the vicinity of 2001 (M7.7) event reveals enhanced strain and seismicity in the KRB and indicates the active nature of faults in the central-eastern KRB (Dumka et al, 2019;Dumka & Rastogi, 2013;Kothyari et al, 2018;Suribabu et al, 2022). The E-W trending Island Belt Fault (IBF) towards the north is supposed to be responsible for the uplift of Bela, Khadir and Pachham Islands (Biswas, 1987(Biswas, , 2005(Biswas, , 2016Biswas & Deshpande, 1970;Dumka, Kotlia, Kothyari, et al, 2018).…”

Tectonic imprints of landscape evolution in the Bhilangana and Mandakini basin, Garhwal Himalaya, India: A geospatial approach

“…Globally, the Digital Elevation data is used as an essential tool in GIS environment to analyze the morphotectonic characteristics of the drainage basins (Montgomery and Foufoula-Georgiou, 1993;Tucker, 1996;Hajam et al, 2013;Kothyari, 2014;Kothyari et al, 2016aKothyari et al, , 2017aKothyari et al, , 2016bWaikar and Nilawar, 2014;Sklar and Dietrich, 1998;Weissel and Seidl, 1998;Singh et al, 2017Singh et al, , 2020Sood et al, 2020). Conventionally, the drainage systems in an active tectonic terrain is impacted by river incisions, active folding and faulting and erodibility which leads to the formation of several alluvial landforms (Schumm, 1986;Keller and Pinter, 1996;Whipple et al, 2013;Kothyari, 2014;Kothyari et al, 2016aKothyari et al, , 2018aTaloor et al, 2017). Active tectonics induced deformation of the valley floor can affect the geometry, aggradation and degradation process of the fluvial network and the deformation can be observed in the form of streams/terrace offsets along the faults (Wallace and Moxham, 1967;Kothyari and Luirei, 2016;Kothyari et al, 2017bKothyari et al, , 2020bKothyari et al, , 2018bBhat et al, 2019).…”