Application of the 'Pejrup Approach' for the Classification of the Sediments in the Microtidal Dyfi Estuary, West Wales, U.K.

Abstract

The classification, texture and distribution of the estuarine intertidal sediments in the microtidal Dyfi Estuary, West Wales, were studied. Evaluation of 72 surficial sediment samples shows that the estuarine intertidal sediments are mostly fine-grained silt and fine-grained sand. By testing Pejrup's triangle diagram for the classification of estuarine sediments, five sub-facies were distinguished from the estuarine intertidal sediments of the estuary. Proceeding seaward, these are saltmarsh, high mud zone, low mud zone and sand flat. Cutting them is an extensive tidal creek network. Textural patterns within the study area show an upward-fining sequence typical of intertidal environments described elsewhere. Most of the investigated sediments fall within the field of deposition controlled by unidirectional currents, which are mainly represented by tidal currents.