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-Since the last Holocene sea level rise, about 6900 BP, a series of deposilional littoral landfonns has been generaled al Ihe oudet of the Guadalquivir River, wilh progradation along lhe predominant longshore drift (Iowards the easl).The first coastal progradation occurred between 6900 and 4500 BP. The Doñana and (perhaps) La Algaida spits, bolh aswcíated wílh the oldest and highest marshland in !he Doñana National Park, are assumed 10 have been developed at an early stage. Originally, the Guadalquivir esluary was wider and deeper than now, and Íls environment was mainly marine,The oldest Huoral fonnations have been dated as ca. 4735 BP, They show erosional events, and indicate the breaking-up 01' earlier spÍl-barriers to form inlets. The marine environment recame increasingly dominant, wi!h heavy erosion of cJiffs and a retreating í.:oastline.This penod was followed by anolhcr sedimentary cycle (4200-2600 BP) that surrounded the earlier erooed bamers. Thc size of the estuary decreased due to the increasing marsh deposits, and a fluvial environment was born.About 2600 years ago, progradation gave way to a new period of Ínlense erosiono The resulting morphology of lilloral slrands and erosional surfaces permitted Ihe relurn 10 a marine environmcnt. The shoreline agaín relreatcd.From 2300 BP, constal progradation has prevniled, with an erosional interruption at 1000 BP. The present-day OUIJet of the Guadalquivir is an estuarine delta of inaclÍve marshland (the Doñana National Park), the dominanl environment is fluvial.

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A multidisciplinary study from a number of drilled cores in the Guadalquivir estuary has made possible to identify as many as three extreme wave events and their facies in the 4th millennium BP (A: ~ 4000 cal yr BP, B: ~ 3550 cal yr BP, and C: ~ 3150 cal yr BP). These events, which caused strong erosion in the Guadalquivir sandy barrier and in the neighboring aeolian systems of El Abalario, brought about significant paleogeographical changes that may have affected human settlements established in the area during the Neolithic and Copper Age periods and during the Middle Bronze Age. The three events can be spatially correlated and their facies differentiated from more proximal to more distal from the coastline. The most proximal facies is characterized by a massive accumulation of shells, a sandy or sandy–muddy matrix, an erosive base, a highly diverse mixture of species (marine and estuarine), and lithoclasts. The most distal facies presents a muddy–sandy matrix, dominance of estuarine fauna, shell accumulation, presence of terrestrial species, mudpebbles, pebbles in a clayey matrix, and bioturbation. The evidence presented will further advance scientific knowledge about the impact of extreme wave events on coastal areas in SW Iberia and NW Africa.