Signatures of Quaternary fluvial response, Upper River Trent, Staffordshire, UK: A synthesis of outcrop, documentary, and GPR data

摘要

The River Trent is the third longest river in Great Britain, and its middle and lower reaches have received extensive study in order to ascertain the controls on fluvial activity and geomorphology throughout the Quaternary. These have yielded data which suggest that the river has been unusually mobile when compared to other British river systems during the Quaternary. However, there have been no previous studies regarding the upstream reaches of the River Trent, and investigations into the internal structure of the fluvio-geomorphological features of the Trent have been limited. This study attempts to help to rectify this skew in the research on an important British river system, in order to enable better future understanding of the river as a whole. The confluence zone of the rivers Trent, Tame, and Mease in Staffordshire, which has recently been shown to be rich in prehistoric-Roman aged archaeological artefacts, is used as a study area. Field-based studies of the geomorphology and sedimentology of Devensian and Holocene aged fluvial deposits are combined with Ground Penetrating Radar data and documentary evidence in order to ascertain the late Quaternary evolution of the river system. These reveal that this reach of the upper Trent has undergone only one cycle of fluvial development since the last glaciation: changing from a braided (Devensian) to an anastomosing (early-mid Holocene) to a meandering (300 BP) system. This suggests that the upper Trent has been more stable than the lower and middle Trent throughout the Holocene. However, it is argued on the basis of local physiographic factors and considerations of stream power that a more active middle section of a river system does not represent atypical behaviour. On this basis it is highlighted how all reaches of a river must be analysed before conclusions can be reached regarding response to external change.