Sedimentary processes on an estuarine marsh island within the turbidity maximum zone of the Yangtze River mouth

Abstract

Sedimentary characteristics and processes on an estuarine marsh island in the Yangtze Estuary (East China Sea) show that (1) the mean grain size of the surficial sediments varies between 0.003 and 0.16 mm, the finest sediment being more enriched in the marsh center particularly under calm weather conditions during the flood season, and the coarsest sediment being more enriched on the low seaward tidal flats particularly after storms; (2) the sediment organic carbon content is generally less than 1.4 wt%; (3) the annual vertical marsh accretion is in the range of 20 cm, with a maximum value of 40 cm in the middle of the marsh; and (4) the seasonal cycle in plant growth strongly influences sediment grain size and erosion-accretion events.