Structural analysis and neotectonic evidences of the dip-slip transverse fault system in the central Mainland Kachchh region, Western India

Abstract

The spatio-temporal changes in the fluvial system and landform of the central Kachchh Mainland region are caused by distinctive ongoing tectonic deformations. The present study aims to decipher ongoing tectonic processes resulting modification of landscape in the Central Mainland Kachchh region during the Late Quaternary period. The region marks the presence of several neotectonic features along the faults indicating rejuvenation of the landform due to tectonic activity. The paleostress analysis of the faults indicates normal faulting due to WNW-ESE, E-W to WSW-ENE directed radial to pure extension. The OSL dates from the strath terrace section confirm accommodation of Quaternary sediments from ∼42ka till ∼32ka. The presence of abandoned channels and obstructed tributary channels across the fault plane deciphers reactivation of extensional fault planes at ∼42ka, constituting accommodation space for sedimentation on the downthrown block forming several sag-fill deposits. The sedimentation ceased after ∼32ka due to regional Kachchh Mainland Uplift (KMU) upliftment triggering vertical incision of channels forming several strath and fluvial terraces. The paleostress analysis and dynamic modification of landform depict reactivation of the hinge faults on the structural Mesozoic bend of the basement high known as the ‘Median High’.