Sea level and climate changes during OIS 5e in the Western Mediterranean

Departamento de Estratigrafía-UCM and Instituto de Geología Económica-CSIC, Universidad Complutense, 28040-Madrid, Spain
Geomorphology (Impact Factor: 2.79). 03/2009; 104(1):22-37. DOI: 10.1016/j.geomorph.2008.05.027
Source: OAI


Palaeontological, geomorphological and sedimentological data supported by isotopic dating on Oxygen Isotopic Stage (OIS) 5e deposits from the Spanish Mediterranean coast, are interpreted with the aim of reconstructing climatic instability in the Northern Hemisphere. Data point to marked climatic instability during the Last Interglacial (OIS 5e), with a change in meteorological conditions and, consequently, in the sedimentary environment. The oolitic facies generated during the first part of OIS 5e (ca. 135 kyr) shift into reddish conglomeratic facies during the second part (ca. 117 kyr). Sea surface Temperature (SST) and salinity are interpreted mainly on the basis of warm Senegalese fauna, which show chronological and spatial differential distribution throughout the Western Mediterranean. Present hydrological and meteorological conditions are used also as modern analogues to reconstruct climatic variability throughout the Last Interglacial, and this variability is interpreted within the wider framework of the North Atlantic record. All the available data indicate an increase in storminess induced by an increase in the influence of north-westerlies, a slight drop of SST in the northern Western Mediterranean, and an important change in meteorological conditions at the end of OIS 5e (117 kyr). These changes correlate well with the decrease in summer insolation and with the climatic instability recorded in North Atlantic high latitudes.

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Available from: Cristino J. Dabrio, Oct 08, 2015
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    • "Sea, including the sand barriers near Alicante, along the Alboran Sea, in the Gulf of Lion, at Cap Bon in Tunisia, and on Sardinia. Their origins are associated with high sea levels in the Pleistocene (Goy and Zazo 1988; Zazo et al. 2003; Elmejdoub and Jedoui 2009; Bardají et al. 2009; Fornós et al. 2009) and the Holocene (Zazo et al. 1993; Barusseau et al. 1996; Goy et al. 2003; Andreucci et al. 2009; Antonioli et al. 2009; Raynal et al. 2009; Dabrio et al. 2011; Sabatier et al. 2011). Many of these ancient barriers can be recognized by their characteristic outcrop morphology on the present-day seafloor (e.g., Alcántara-Carrió et al. 2013, this volume), but others are completely buried and can therefore be identified only on seismic records (Tesson et al. 2005; Raynal et al. 2009). "
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    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.
    Geo-Marine Letters 04/2013; 33(2 - 3):217-223. DOI:10.1007/s00367-012-0315-x · 2.12 Impact Factor
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    • "The Last Interglacial (MIS 5; sensu lato, Kukla et al., 1997) age of the sediment was inferred from observations of field morphology, from the presence of the Senegal fauna (warm-loving fauna from Senegal, an eco-stratigraphic indicator for MIS 5; for details see Mauz and Antonioli, 2009) and from previous studies (Table 1). Optical (optically stimulated luminescence, OSL) dating of quartz was used to determine the exact timing of ooid formation during MIS 5. Sample preparation followed standard procedures to extract sand-sized quartz grains from carbonate-rich sediment samples (Mauz et al., 2002). "
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    Quaternary Science Reviews 10/2012; Volume 54:89-98. DOI:10.1016/j.quascirev.2012.02.021 · 4.57 Impact Factor
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    • "Although potentially useful for this study, we avoided making predictions for the last interglacial phase (about 135 000–115 000 BP), because of a lack of detailed bioclimatic data for this period. However, it is worth mentioning that palaeoclimatic conditions during this period were in many respects similar to current ones in the Western Mediterranean basin (Bardají et al. 2009 and references therein). As our specific aim was to predict the potential effect of sea level drop during the last glacial phase, the models were built by considering only the Corsica–Sardinia microplate, i.e. an area that was largely and persistently connected into a single landmass during the Pleistocene glaciations. "
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    ABSTRACT: Many temperate species experienced demographic and range contractions in response to climatic changes during Pleistocene glaciations. In this study, we investigate the evolutionary history of the Tyrrhenian tree frog Hyla sarda, a species inhabiting the Corsica-Sardinia island system (Western Mediterranean basin). We used sequence analysis of two mitochondrial (overall 1229 bp) and three nuclear (overall 1692 bp) gene fragments to assess the phylogeography and demographic history of this species, and species distribution modelling (SDM) to predict its range variation over time. Phylogeographic, historical demographic and SDM analyses consistently indicate that H. sarda does not conform to the scenario generally expected for temperate species but rather underwent demographic and range expansion mostly during the last glacial phase. Palaeogeographic data and SDM analyses suggest that such expansion was driven by the glaciation-induced increase in lowland areas during marine regression. This unusual scenario suggests that at least some temperate species may not have suffered the adverse effects of glacial climate on their population size and range extent, owing to the mitigating effects of other glaciations-induced palaeoenvironmental changes. We discuss previous clues for the occurrence of such a scenario in other species and some possible challenges with its identification. Early phylogeographic literature suggested that responses to the Pleistocene glacial-interglacial cycles were expected to vary among species and regions. Our results point out that such variation may have been greater than previously thought.
    Molecular Ecology 11/2011; 20(24):5313-27. DOI:10.1111/j.1365-294X.2011.05363.x · 6.49 Impact Factor
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