Modeling the sorting of sediments on delta tops

Abstract

Sediment sorting in fluvial rivers produces great variation in the grain-size of deposit over the length of a river. Knowledge of the pattern of sediment deposition may help to shed light on the processes that sort by grain size. A simple geometric model was developed to predict the location of the transition between coarse and fine sediment in a bimodal sediment distribution and tested against flume-created deposits with a variety of flow and depositional conditions. The models agreed well with the overall form of plane-bed clinoform deposits but not with rippled-bed clinoform deposits, thus a new model for predicting transitions in rippled-bed deposits is needed.