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- Foraminifera as tsunami tracers in Holocene sequences of Southwestern SpainPublication . Guerra, Liliana; Ruiz, F.; Abad, Manuel; Veiga-Pires, C.El objetivo de este trabajo es la identificación de eventos de alta energia (tsunamis?) em el P.N. de Doñana a partir del análisis de asociaciones de foraminíferos, llevando a cabo en un testigo corto, y comparar estos datos con el registro del Tsunami de 1755 que tuvo lugar en el SO de la Península Ibérica, donde los foraminíferos se han mostrado como indicadores muy útiles para caracterizar los paleoambientes pre- y postsunami y delimitar capas tsunamigénicas. The southwestern Spanish coast is a low-probability tsunamigenic area (e.g., Reichester, 2001), although sixteen tsunami have been documented for the time-period between 218 BC and 1900 AD (Campos, 1991). These high-energy events have tremendous morphological effects and drastic ecological impacts in coastal areas (Borrero, 2005) and cause the deposition of sedimentary beds with characteristic textural and mineralogical features (e.g. Babu et al., 2007).
- El contraste micropaleontológico de la Historia: el Lacus Ligustinus romanoPublication . Guerra, Liliana; C. Veiga-Pires, C.; González-Regalado, María Luz; Abad, Manuel; Toscano, Antonio; Muñoz, Juan Manuel; Ruiz, Francisco; Rodríguez Vidal, Joaquín; Cáceres, Luis Miguel; Izquierdo, Tatiana; Carretero, María Isabel; Pozo, Manuel; Monge, Guadalupe; Tosquella, Josep; Gómez, Paula; Romero, Verónica; Arroyo, Marta; Gómez, GabrlelDuring the Roman period (3rd century BC-5th century AD), the areas located near the present-day mouth of the Guadalquivir River were occupied by a lagoon with marine connection, according to the paleoenvironmental interpretation of benthic foraminiferal assemblages obtained in a core extracted in the Donana National Park. The inner zones of this lagoon were occupied by clayey tidal flats, which suffered the effects of a storm towards the end of the 1st century A.D. The comparison with the ostracod assemblages of the same core confirms this reconstruction and the paleogeographic data provided by various chroniclers, although these microcrustaceans better record the paleoenvironmental changes in these coastal sectors.
- Late holocene benthic Foraminifera of the Roman Lacus ligustinus (SW Spain): a paleoenvironmental approachPublication . Guerra, Liliana; Veiga-Pires, Cristina; Luz Gonzalez Regalado, M. L.; Abad, M.; Toscano, A.; Manuel Munoz, J. M.; Ruiz, F.; Vidal, J. R.; Caceres, L. M.; Izquierdo, T.; Carretero, M. I.; Pozo, M.; Monge, G.; Tosquella, J.; Prudencio, M. I.; Dias, M.I.; Marques, R.; Gomez, P.; Romero, V.This paper studies the Late Holocene benthic foraminifera from a continuous core extracted in the Doliana National Park (SW Spain). In this core, the foraminiferal assemblages confirm the Late Holocene lagoon (historically so-called Locus Ligustinus) during the Roman period, about 2000 years ago. The more open, deepest areas of this lagoon were dominated by Ammonia tepida and Elphidium spp., while Haynesina germanise was the most representative species of the shallow, more restricted zones. The vertical variations of these assemblages, together with associated sedimentological and macrofaunal changes, allow recognizing three high-energy events (HEE) between 500 BCE and 500 CE, which also left an extensive sedimentary record in nearby coastal areas: two tsunamis (HEE-1 and HEE-3) and a storminess period (HEE-2).
- GIS and Palaentology integrated application for the recognition of tsunamigenic events in Doñana National ParkPublication . Guerra, Liliana de Castro Dias; Ruiz, Francisco; Veiga-Pires, C.The present work aimed to characterize the actual and past environments at Doñana National Park (SW Spain) throughout the study of benthic foraminifera assemblages at two drill holes (cores C and D, from Ruiz et al., 2004) and twenty surface samples, as well as to recognize and confirm the occurrence of extreme energy events (storms/tsunamis) around 2165 yrs B.P. (215 yrs BC). The studied tsunamigenic beds have between 8 to 26 cm in Core C and 40 to 10 cm in Core D. Almost all the variables studied in the present work concur with previous works on tsunamigenic layers found worldwide. These variables include the foraminifera species found in the tsunamigenic layer, the composition of sand beds (suggesting strong waves and currents), the presence of reworked molluscs, marine foraminifera taxa, high values for planktonic/benthic ratio, and high Shannon H, Fisher Alpha and Species richness diversity indexes. In our case the diversity index that evidences the most the occurrence of a tsunami seems to be Fisher Alpha, which value is much higher than the other registered in both cores. Regarding foraminifera species, results with relative abundance >1% were considered in the present work, rather than abundances >5% as used by many authors. These results show the presence of marine foraminifera at the tsunamigenic layers, and their absence in the remaining records, which appeared extremely important for the recognition of the occurrence of these high energy events. From the twenty surface samples studied, only eight presented foraminifera content, which did not allow to compare the actual environments with the palaeoenvironments recorded in Cores C and D. Finally, ArcGIS software and Geosoft Target extension helped the micropalaeontological study, enabling to confirm the palaeoenvironmts description made for Doñana National Park by other authors, as well as the occurrence of palaeotsunamis in this area.
- Síntese da história da Evolução Holocénica do Parque Nacional de Doñana (Espanha): evolução paleoambiental, influência climática, eventos energéticos extremos e registro de foraminíferosPublication . Guerra, Liliana; Veiga-Pires, C.; Ruiz, F.; Abad, ManuelO presente trabalho tem como objectivo realizar uma síntese da evolução paleogeográfica do Parque Nacional de Doñana, através de uma compilação da informação previamente publicada sobre o assunto, incluindo a descrição geral das variações climáticas tardi-holocénicas na Península Ibérica. Dados sedimentológicos e de microfauna de dois cores e o registo histórico de eventos energéticos extremos em Portugal e Espanha são igualmente combinados e discutidos no que diz respeito ao reconhecimento dos intervalos climáticos e eventos tsunamigénicos. Os resultados mostram que a evolução paleogeográfica do Parque Nacional de Doñana parece certamente ligada às mudanças climáticas e à ocorrência de eventos energéticos extremos como observado para o tsunami de 2168-2159 B.P., durante o período Sub-Atlântico.
- Morpho-sedimentary evidence of Holocene tsunamis in Southwestern Spain estuaries: a summaryPublication . Ruiz, F.; Rodriguez-Vidal, J.; Cáceres, L. M.; Carretero, M. I.; Pozo, Manuel; Gómez-Toscano, F.; Izquierdo, T.; Font, Eric; Guerra, Liliana; Veiga-Pires, C.; Abad, ManuelLos estuarios constituyen sistemas costeros excelentes para registrar tsunamis a través de un amplio tipo de evidencias geológicas. Este trabajo revisa y resume las evidencias de tsunamis prehistóricos e históricos en los quatro principales estuarios del suroeste de España. Las más frecuentes son erosión de playas y retroceso del litoral, ruptura y desbordamiento de flechas arenosas y depósito de capas bioclásticas. En la actualidad, estas características se encuentran particularmente bien estudiadas en los estuarios del Tinto-Odiel, Guadalquivir y Guadalete, mientras que son necesarios trabajos más detallados en el sector de influencia marina del estuario del Rio Guadiana.
- Hydro-sedimentary processes in a beach-headland systemPublication . Moura, Delminda; Veiga-Pires, C.; Oliveira, Sónia; Horta, João; Nascimento, Ana; Gomes, Ana; Guerra, LilianaUnderstanding hydro-sedimentary processes in space-limited environments as embayed beaches is a key question to reconstruct preterit and predict future coastal evolution forced by the mean sea level rise. Moreover, such knowledge is a fundamental management tool in areas where coastal erosion is currently a worrying fact. This work aims thus to assess the sedimentary contribute, provided by the alongshore transport, to feed embayed beaches. At the southernmost rocky coast of Portugal (Algarve), beaches occurring at the cliffs’ foot are separated by headlands connected to shore platforms forming littoral cells as a consequence of the extremely karstified carbonate landscape. The survival of those beaches depends almost exclusively on the alongshore drift.
- From a marsh that was once sea: the geological evolution of Europe's largest biological reserve as told by its benthic foraminifera-a reviewPublication . González-Regalado, María Luz; Guerra, Liliana; Ruiz, Francisco; Veiga-Pires, Cristina; Abad, Manuel; Izquierdo, Tatiana; Vidal, Joaquín Rodríguez; Cáceres, Luis Miguel; Muñiz, Fernando; Carretero, María Isabel; Tosquella, Josep; Muñoz, Adolfo Francisco; Pozo, Manuel; Muñoz, Juan Manuel; Toscano, Antonio; Gómez, Paula; Romero, Verónica; Gómez, GabrielThis paper presents an updated list of benthic foraminifera found in brackish and marine (paleo-)environments of the Donana National Park (SW Spain) from the Lower Pliocene to the present-day. This list, based on published records, includes ninety-four species whose autoecology and temporal distribution in surface sections and continuous sediment cores allow us to infer the palaeogeographic evolution of this Biosphere Reserve over the last millions of years. During the Lower Pliocene, this area was occupied by a wide shallow bay with Nonion faba and Ammonia beccarii as the most representative species. During the Upper Pliocene, there was a transition to terrestrial environments, later dominated by fluvial dynamics for much of the Pleistocene and devoid of these aquatic microorganisms. During the Upper Pleistocene and part of the Holocene, the park was flooded during the MIS-1 transgression and a large lagoon was formed and progressively silted up. At this stage, benthic foraminiferal assemblages were dominated by the brackish species Ammonia morphogroup tepida and Haynesina germanica, which were occasionally replaced by marine species (mainly miliolids) during high-energy events. Currently, benthic foraminifera are mainly represented by Ammonia morphogroup tepida in the temporary lagoons and distributary channels, while Ammonia beccarii is dominant in their marginal marine areas. In summary, there is a clear correspondence between the palaeogeographic evolution of the park and its benthic foraminiferal associations, a review of which contributes to increase the knowledge of its remarkable present and past faunal diversity.