Mid to late Quaternary Fluvial activity in allochthonous river systems of the Maharashtra Plateau, India: A review and new observations

Abstract

The Maharashtra Plateau dominantly displays an erosional landscape and the Quaternary alluvial deposits in the valleys are remarkably limited in areal extent and thickness. The only exceptions are the infilled basins/valleys downstream of bedrock gorges with knickpoints. Earlier studies have inferred a good correspondence between the major changes in the monsoon regime and the fluvial activity (aggradation and incision/excavation) on the regional–scale during the last ~103 –105 years. However, geomorphic evidence suggests that some of the mid to late Quaternary aggradational events may not be directly related to known climatic events and the fluvial activity in some of the tributaries did not correspond with the recognized regional behavioural pattern. Basin–specific tectonic activity as well as alterations in the isohyetal pattern in the rainshadow zone appear to be the plausible reasons for the observed variations in the fluvial responses. The relationship between Quaternary climate changes and the fluvial activity, even in this area of uniform lithology, appears to be a complex one.