Turia river delta and coastal barrier-lagoon of Valencia (Mediterranean coast of Spain): Geomorphological processes and global climate fluctuations since Iberian-Roman times

Abstract

Extensive drillings and 31 new C-14 datings were used to establish the geomorphological evolution of the Turia river delta and coastal barrier-lagoon system of Valencia (Spain) over the last three millennia. Integration of geomorphological, stratigraphic, malacological, sedimentological and geoarchaeological data enables us to relate river Turia avulsions and alluvial episodes to the development of coastal spits and barriers. Geomorphological changes in the study area may also be associated with global climate events, sea-level fluctuations or anthropogenic periods in the Turia catchment.Six phases may be differentiated: (1) a major early alluviation phase during the Iberian period, when the Turia river ran to the north of the coastal plain and sand spits closed the Valencia open lagoon environments, forming a permeable barrier (2800 BP to 2300 BP approximately); (2) an avulsion phase of the Turia river to the south at the end of the Roman period (4th century AD); (3) formation of a more advanced spit just behind the most recent barrier during the Late Antique Little Ice Age (LALIA, Visigothic period); (4) a flood period of high-magnitude with coarser sediments throughout the Medieval Climate Anomaly (MCA, 11th century AD), when La Punta meridional deltaic ridge developed, which can be related to beach ridge closing and marine isolation of the Valencia lagoon around the 12th century; (5) important river alluviation and growth of the recent coastal barrier favoured by Turia channel changes during the Middle Ages, in the early Little Ice Age (LIA); (6) rapid coastal progradation and decline in salinity in the Valencia lagoon between the Maunder sunspot minimum (MM) and the end of LIA.