An unusual Holocene fan-shaped subaqueous prograding body at the back of the Cies Islands ridge (Ria de Vigo, NW Spain): Geomorphology, facies and stratigraphic architecture

摘要

The internal structure of a new subaqueous sedimentary body with a 3D morphology of a fan was studied using an interdisciplinary approach based on geophysical, geomorphological, sedimentological and radiocarbon data. The genesis of the sedimentary body is controlled by two main factors: (1) the presence of a basement ridge that constitutes the Cies archipelago, acting as a barrier that protects the ria from high-energy marine events; and (2) the W-SW swell direction under stormy conditions, which sweeps the sediment from the platform and introduces it into the ria through the narrow entrance between Faro and San Martino Islands.