<p>Extensive coseismic liquefaction features, such as sand dykes and vents, ephemeral sand-water springs, and lateral spreading, have developed along the riverbanks in the meizoseismal area of the Mw 6.0 (April 28, 2021) earthquake in the northern Kopili Fault Zone (Brahmaputra Plain, Himalayan Piedmont zone). To explore their stratigraphic and structural expressions, we mapped and excavated shallow trenches across the coseismic liquefaction features in the sediment profile of the point-bar deposits. The paleoliquefaction features, suggesting the occurrence of a past event, were also observed in the sediment profile. The subsurface architecture of sand boils/blows, feeder-dykes, soft-sediment deformation (SSD) structures, depth of liquified sand bed, thickness of confining cover bed, and depth of water table helped establish the boundary conditions for the SSD. We dated the sediment profile using the OSL (Optically stimulated luminescence) dating technique to constrain the age of the present and paleoliquefied sediments. The analysis of liquefaction results suggests that either the 1714-Bhutan earthquake or a contemporary event in southern KFZ was responsible for triggering the observed SSD-1 structures. The study also highlights the significance of favorable boundary conditions for the occurrence of liquefaction features at moderate-magnitude events and the importance of even a shallow sediment profile as a paleoseismic repository.</p> Graphical Abstract <p></p>