Seismic evidence for the preservation of several stacked Pleistocene coastal barrier/lagoon systems on the Gulf of Valencia continental shelf (western Mediterranean)

Abstract

The focus of this study is the analysis of coastal sand barriers and associated coastal lagoons on the inner continental shelf of the Gulf of Valencia (western Mediterranean), based on two W–E seismic profiles recorded seaward of the Albufera de Valencia coastal lagoon. Seismic facies identified include a number of coastal sand barriers with landward lagoons draped by contemporary continental shelf deposits. The barrier systems have been grouped into two sedimentary systems tracts, the older one corresponding to a prograding/aggrading highstand systems tract involving at least four paleo-coastal sand barrier/lagoon systems, followed landward by a transgressive systems tract comprising three such systems. All the systems have been allocated a Tyrrhenian age, the formation of individual barrier systems having been associated with successive sea-level stillstands, and their present-day position being explained by the very high regional subsidence rate. In summary, this study demonstrates that the Quaternary stratigraphic record of the Gulf of Valencia inner continental shelf is composed of littoral sand facies, in particular coastal sand barrier and lagoon deposits. These findings are in agreement with corresponding observations on other continental shelves of the western Mediterranean, showing that the formation of coastal sand barriers was a characteristic feature of this region during the Quaternary.