Soft Sediment Deformation Structures from Khari River Section of Rudramata Member, Jhuran Formation, Kutch: A Testimony of Jurassic Seismites

Abstract

Soft sediment deformation structures such as slump folds, clastic dyke, syn-sedimentary faults and convolute bedding are present in the coarse – fine grained yellowish buff coloured sandstone, and interbedded reddish brown fine grained sandstone and yellowish – white siltstone at the Khari River section belonging to Rudramata member of Jhuran Formation (Upper Jurassic), Kutch. These soft sediment deformation structures are confined to lower and middle parts of the section and are invariably underlain as well as overlain by undeformed beds that have restricted lateral and vertical extent and occur in close proximity of Kutch Mainland Fault, thereby suggesting that these structures were formed by seismic activity and therefore represents seismites.

Soft Sediment Deformation Structures in the Sediment Deposits of Ganga River and Its Oxbow Lakes in Parts of Indo-Gangetic Plain: Implications for Quake Proxies and Paleoseismicity Tracking

“…Shaking of water-saturated sediments by seismic shocks and factors controlling the physical characteristics of sediments such as porosity, permeability, cohesion generates soft-sediment deformation, and fluid escape structures [14]. Earlier research on SSDS was centered on older sediments, such as Proterozoic Vindhyan sediments, Chaibasa Formation, Cuddapah sediments [15] [16] [17] [18], Mesozoic sediments [19] [20], and Paleozoic [21] [22]. However, there is meager work on SSDS of Quaternary sediments of the Himalayan region, such as Karewas [23], and almost nil in the Ganga basin.…”