Depositional Pattern in Upland Surfaces of Central Gangetic Plain Near Lucknow

Several meter thick muddy sequences make up the topmost part of upland surfaces in Central Gangetic Plain. Excavations in the river-valley terrace (T₁-surface) of Gomti River show about 4 m thick fine-grained deposits, which are underlain by a meter thick sand body: The sand of such sand bodies is coarser-grained than the present-day Gomti River sand. The sequence is essentially a silty very fine sand, highly mottled due to extensive bioturbation. These muddy successions are deposited by sheet floods of monsoon rains and not linked to flood plain of present-day active river. The high plateau surface (T₂-surface) shows locally a few meter thick channel fill sequences, produced by small channels which have been abandoned. The muddy sediments of upland surfaces show high degree of variability.