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El estudio del registro sedimentario holoceno del estuario de los ríos Tinto y Odiel (Huelva) se ha realizado históricamente por medio de sondeos y de afloramientos superficiales. Nuevos perfiles naturales en la Isla de Saltés (La Cascajera) están ofreciendo una nueva perspectiva sobre la génesis y cronología de los depósitos. Para la determinación temporal de estos procesos se llevaron a cabo dataciones radiométricas mediante el análisis de series de Uranio y de radiocarbono. El contraste de los resultados de ambas técnicas ha permitido observar grandes desfases temporales en las series de Uranio, siendo las edades de 14C unos 200 años más antiguas que las de U/Th, para las mismas muestras. La contaminación postsedimentaria en estos sistemas abiertos, ha favorecido el rejuvenecimiento de la edad de la muestra, por el continuo aporte al sistema de 234U y 238U. Esto pone de manifiesto lo inapropiado del método U/Th en sedimentos estuarinos recientes y, sobre todo, altamente contaminados; no debiendo utilizarse este método de forma exclusiva. El método de radiocarbono parece ser más preciso y adecuado, aplicándose a los resultados las pertinentes calibraciones marinas regionales (ΔR), siendo aconsejable su modelización Bayesiana (OxCal)., The study of the Holocene sedimentary record of the Estuary of the Tinto and Odiel rivers (Huelva) has been carried out historically by boreholes and surficial outcrops. New natural profiles on Saltés Island (La Cascajera) are offering a new perspective on the genesis and chronology of the deposits. For the temporal determination of these processes, radiometric dating was carried out by radiocarbon and uranium series analysis, being the ages of 14C are about 200 years older than those of U / Th, for the same samples. The contrast of the results of both techniques has allowed us to observe large time lags in the uranium series. Post-sedimentary contam ination in these open systems has favored the rejuvenation of the age of the samples, due to the continuous contribution of 234U and 238U to the system. This highlights the inappropriateness of the U/Th method in recent estuarine sediments and, above all, highly polluted; therefore, this method shouldn’t be used exclusively. The radiocarbon method seems to be more precise and adequate, always applying the pertinent regional marine calibrations (ΔR) to the conventional results, being advisable a Bayesian modeling (OxCal).

Main tsunami records around the world coasts are associated with low-lying sandy coasts or estuarine areas. In the Rock of Gibraltar formed by limestone cliffs these records are less common and they are limited to the lagoon (The Inundation) located at the isthmus that joins the Rock with the mainland. Tsunamigenic deposits filling deep open crevices that record marine events since ca. 3,000 years BP have been studied at the southwestern end, i.e. Rosia Bay. The most represented deposits could be related with both Atlantic and Mediterranean tsunamis occurred in ~1000 BC, 218-209 BC, 60 AD, 365 AD and 1755 AD. These new tsunamite-type evidence represent a complementary tool in the geological analysis and chronology of these high-energy marine events.

The first human settlements (6000−4000 BP) in the early estuary of the Tinto and Odiel rivers were located in the ancient coastal banks or in the nearby hills. From 4000 years BP onwards, the estuarine sediments started to emerge as sand barriers and chenier plains, prograding towards the mouth. As the littoral strands stabilized morphologically, they are colonized by human settlements in successive periods, the oldest inland (Almendral) and more recent outward (Cascajera). These emerged morphologies were surrounded by muddy tidal flats in the estuary and only the high-energy marine events such as a tsunami or extraordinary storms were able to modify both the landscape and human settlements installed on them. This work also describes the morphodynamicmodel that built the chenier plain of La Cascajera. Ministerio de Ciencia, Innovación y Universidades CGL2010-15810/BTE Ministerio de Ciencia, Innovación y Universidades HAR2012- 36008 Junta de Andalucía SEJ-4770

Este trabajo analiza las evidencias de depredación observadas en la revisión de más de 5.000 valvas y caparazones de ostrácodos extraídos en sedimentos holocenos del Parque Nacional de Doñana (SO de España). Estas evidencias son muy escasas (0,15%), debido en parte a la alta proporción de mudas juveniles. Se pueden distinguir dos tipos de perforaciones (Oichnus paraboloides Bromley y Oichnus simplex Bromely), localizadas preferentemente en las áreas central y anterior de las valvas y atribuidas principalmente al ataque de gasterópodos. Estas perforaciones afectan a los adultos y a las últimas mudas juveniles de especies con ornamentación externa lisa. No se existe correlación estadística entre la abundancia de ostrácodos y el número o porcentaje de valvas depredadas, así como entre el diámetro de las perforaciones y el tamaño de las valvas que las presentan. This paper examines the evidences of predation observed in the study of more than 5,000 ostracod shells extracted from Holocene sediments of the Doñana National Park (SW Spain). These evidences are very rare, partly due to the high proportions of juvenile instars. Two types of evidences are distinguished (Oichnus paraboloides Bromley and Oichnus simplex Bromley), preferentially located in the central and anterior areas of the valves and attributed mainly to gastropods. These holes were found in adults and the last juvenile instars of species with smooth shells. There is not statistical correlation between: a) the abundance of ostracods and the number or percentage of predated shells; and b) the hole diameter and the size of the valves that contain them.

Este trabajo analiza las evidencias de depredación observadas en la revisión de más de 5.000 valvas y caparazones de ostrácodos extraídos en sedimentos holocenos del Parque Nacional de Doñana (SO de España). Estas evidencias son muy escasas (0,15%), debido en parte a la alta proporción de mudas juveniles. Se pueden distinguir dos tipos de perforaciones (Oichnus paraboloides Bromley y Oichnus simplex Bromely), localizadas preferentemente en las áreas central y anterior de las valvas y atribuidas principalmente al ataque de gasterópodos. Estas perforaciones afectan a los adultos y a las últimas mudas juveniles de especies con ornamentación externa lisa. No se existe correlación estadística entre la abundancia de ostrácodos y el número o porcentaje de valvas depredadas, así como entre el diámetro de las perforaciones y el tamaño de las valvas que las presentan., This paper examines the evidences of predation observed in the study of more than 5,000 ostracod shells extracted from Holocene sediments of the Doñana National Park (SW Spain). These evidences are very rare, partly due to the high proportions of juvenile instars. Two types of evidences are distinguished (Oichnus paraboloides Bromley and Oichnus simplex Bromley), preferentially located in the central and anterior areas of the valves and attributed mainly to gastropods. These holes were found in adults and the last juvenile instars of species with smooth shells. There is not statistical correlation between: a) the abundance of ostracods and the number or percentage of predated shells; and b) the hole diameter and the size of the valves that contain them.

The georñorphological and palaeontological studies of the Las Nuevas estuaríne ridge indicates that these silty sands with abundant macrofaune were deposited over clayey marsh deposits during some erosive events at approximately 2000-1800 Cal UC years BP. >4 detailed analysis of the macro- and microfaune included in two drillings collected in this unit permits to delimitate two palaeogeographic sectors during this period: a) to the western, a lagoon with little to very little tidal renewal and; b) the main channel, introducing abundant marine microfaune toward the salt marshes during the tidal fluxes

The georñorphological and palaeontological studies of the Las Nuevas estuaríne ridge indicates that these silty sands with abundant macrofaune were deposited over clayey marsh deposits during some erosive events at approximately 2000-1800 Cal UC years BP. >4 detailed analysis of the macro- and microfaune included in two drillings collected in this unit permits to delimitate two palaeogeographic sectors during this period: a) to the western, a lagoon with little to very little tidal renewal and; b) the main channel, introducing abundant marine microfaune toward the salt marshes during the tidal fluxes