TITLE:
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
AUTHORS:
Gufran Ali, Mohd Sajid, Mohammad Shamim Khan
KEYWORDS:
Quaternary Sediments, Flood Plain, Central Ganga Basin, Sediment Dynamism, Himalayan Uplift, Paleoquakes
JOURNAL NAME:
International Journal of Geosciences,
Vol.14 No.1,
January
31,
2023
ABSTRACT: The Late Quaternary thick sedimentary fills of the Ganga basin predominantly consist of unconsolidated fluvial sandy deposits which are often
intercalated with mud. These deposits at various places record
the evidence of earthquakes, which occurred in the recent geological past. The evidence is contained and manifested in the form
of Soft Sediment Deformation Structures (SSDSs). Saturated
sediments/muds/soils are liquefied by earthquake tremors which either generate SSDS or produce structural
discordance in the pre-existing sedimentary structures. The present study reports the occurrence of SSDS, e.g. load and
associated flame structures, clastic dikes and sill structures, slump
structures and sedimentary breccias, etc.
from the Ganga River and adjacent oxbow lake
sediment deposits. An attempt has been made to establish the origin of soft sediment structures of this region in
accordance with its neotectonic history and in turn, identification of seismic structural proxies to
delineate paleoseismic events in this region with futuristic
implications. The preservation of soft sediment deformation structures in large
numbers with multiple geomorphology and scale, in the river and adjoining lake
sediments, is indicative of frequent earthquakes of high magnitude consequent
to tectonic activism in the Himalayan region.