Climate-induced variability in the Late Pleistocene–Holocene fluvial and fluvio-deltaic successions in the Ganga plains, India: A synthesis

The present knowledge of climate variability in the Indian sub-continent from terrestrial records is extremely widespread. Very few studies, backed by sound chronological database, extend to the full duration of even Late Quaternary. A critical evaluation of the available stratigraphic as well as chronological data needs to be undertaken to establish secure proxy-climatic indicators in the Indian-sub-continent. This paper presents a synthesis of the available fluvial and fluvio-deltaic successions for the Late Pleistocene–Holocene period from the Ganga basin. The Ganga basin, trending parallel to the strike of the Himalayan foreland, shows a clear expression of variability of modern climate as precipitation doubles in a west to east transect from east of Delhi to east of Kolkata. This has resulted in complex spatial response of river systems because of variable stream power and sediment discharges that result in present-day degradational and aggradational regimes across the plains. We believe that such geomorphic diversity has existed over most of the Late Quaternary as is manifested in significant spatial variability in the alluvial architecture developed below the plains. We have analyzed the fluvial and fluvio-deltaic sedimentary successions in the Ganga basin and highlighted the influence of climatic variability in the generation of these successions.