Geometría de los depósitos litorales en el ámbito urbano y la bahía de Gijón (NO de España)

Abstract

A large part of the urban area of Gijón is located on sandy sediments linked to an old estuarine system of beach and dunes, sandy bay and marshes. This Quaternary layer, which lies on a Jurassic bedrock, reaches thicknesses greater than 20 m in the northern margin of the city, corresponding with different climatic stages of the almost disappeared estuary of Gijón. The sediments extend towards the N, filling a paleo-valley studied from a bathymetric reconstruction of the bay that was comple- mented with a geophysical survey (Flor-Blanco et al., 2016). This research reviews and reinterprets the available data on the distribution and thickness of the estuarine sediments in the urban subsoil (Pando et al., 2016; García-Rodríguez, 2018), incorporates information coming from new boreholes, and analyzes the results of the geophysical survey, which estimated thicknesses of the sediments locally above 15 m. This has allowed the integration of the two filling areas and, for the first time, to evaluate the geometry of the deposits as a whole. It has also been possible to investigate the morphology of the bedrock under the sedimentary filling.