Constraints of lithostratigraphy on the landscape evolution in response of erosion, climate and tectonics in the Marginal Ganga Plain, India

[Display omitted] •Continental Sequence stratigraphy of the Marginal Ganga Plain is discussed.•3-D model reveals the regional stratigraphic framework of the MGP.•The MGP comprises three depositional sequences and four sequence boundaries.•The MGP defines variable accommodation to sediment supply ratio (A/S).•Surface morphology of the MGP is controlled by the forebulge tectonics. The Marginal Ganga Plain (MGP) exhibits up to 160 m thick fluvial sedimentary record of the Late Quaternary forebulge dynamics. The mineralogical composition of sediments from forty boreholes reveals three major depositional sequences (DS1, DS2, and DS3) and four sequence boundaries Sb1, Sb2, Sb3 and Sb4 representing where different tectonic and climatic conditions exercised parental control. These sequence boundaries are demarcated by the shift in facies architecture. The Sb1 sequence boundary is locally developed over the basement rocks. The lowermost DS1 represents a thick floodplain and low sinuosity channel association at > 114 ka under stable landscape. This DS1 indicates a low rate of sedimentation and High Accommodation Systems Tract (HAST), characterized by positive > 1 A/S (Accommodation to Sediment) ratio. The sequence boundary Sb2 lies between DS1 and overlying DS2 implies a regional unconformity in the MGP and negative A/S ratio. Further, laterally extensive asymmetrical DS2, developed between ~ 80–54 ka with an erosional base overlies the DS1 and represents Low Accommodation Systems Tract (LAST) with A/S 1. The Sb4 represents the top surface of the DS3 and is currently getting degraded by ravinement processes. The varying pattern of alluvial architecture in the MGP defines variable A/S ratio and infer forebulge tectonic signature shaping the fluvial landscape.