Grain size analysis using the Malvern Mastersizer on selected samples commonly revealed a bimodal distribution which was dominantly silt to clay, however sand was also present. The lagoonal sediments commonly show the effects of iron oxide staining from inter-tidal and subaerial exposure. The top 1-2 meters of the cores are enriched with fragments of anthropic material on all island settings. In the longer cores, a base to the lagoonal stratigraphy was found at depths varying from 4-6 meters. Pre-lagoonal fluvial sands contain no shells and are locally overlain by anoxic clays.
Cores provide evidence of tidal channel meanders which have migrated throughout the Lagoon.
The rate and depth of channel migration will be determined by forthcoming AMS-14C dates. Channel inlet and barrier beach migration are also clearly seen in the cores from the Lido Barrier Island at San Nicolo which are dominated by buff beach sands. Variations in the nature of the cored lagoonal sediments provide an impetus for improved sampling density in future expeditions. This data base and analysis also has implications for archeological research as well as coastal and environmental management practices.