Quaternary stratigraphy and sedimentology of the Korea section on the Betwa River, southern Gangetic Plains, Uttar Pradesh

Abstract

Floodplain deposits are exposed in an about 29 m high cliff section at Kotra along the Betwa river, a tributary of the Yamuna river at the southern margin of the Gangetic Plains. The Betwa is a peninsular river originating in the Bundelkhand Craton parts of which are exposed as bedrock close to the section. The Betwa river is incised and bordered by an extensive zone of badland (dissected into gullies). The stratigraphic units comprise pedogenized floodplain muds and reworked carbonate gravels that fill small plains-fed channels. Gully fills of mud and gravel mark extensive degradational surfaces that divide the section into discontinuity-bounded units, currently of unknown duration and age. Closely spaced discontinuities low in the section may mark a former interfluve level, after which a thick floodplain succession accumulated up to the level of the modern clifftop. Presence of prominent discontinuities and thick floodplain deposits in the cliff sections suggest that the late Quaternary history of the southern plains is marked by cycles of channel incision and floodplain degradation and alluviation.