Quaternary Stratigraphy and Sedimentology of the Kotra Section on the Betwa River, Southern Gangetic Plains, Uttar Pradesh

Abstract

Floodplain deposits are exposed in an about 29 rn 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 sectipn. 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 grayels 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 discontiquities low in the section may mark a former interfluve level, after which a thick floodplain succession accumulated up to the level of the modem 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.