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The fossil record is the main tool to reconstruct the evolution of life on Earth. Because continuous and deep relationships exist between the biota and the abiotic environment, the analysis of the structures of the biotic assemblages has a key-role in the understanding the history of our planet. The planktonic and benthonic assemblages, which are widespread from coastal areas to open ocean, are a tool to investigate the paleoclimatic changes and the development of the Earth climate system and to predict its future evolution. The planktonic (coccolithophores and planktonic foraminifers) and benthonic (ostracods) assemblages of ODP Site 974 located in the central Tyrrhenian Sea and the assemblages of piston cores C -106, C-101 and C9, located in the Gulf of Salerno and Gaeta were analyzed.
The oxygen isotope stratigraphy, the calcareous nannofossils events and C14 data, provided the stratigraphic constrains (Amore et al, 2000; Buccheri et al., 2002). The studied interval ranges from MIS 1 to MIS 3. This interval is characterized by intense changes of environmental factors like light, salinity, temperature of water masses, nutrient availability, terrigenous inputs and water turbidity, which are directly related to climatic and global sea level changes.
The cores have been sampled at an average spacing distance of 2cm. The quantitative counting and the statistical analysis of the planktonic and benthonic assemblages is focused to highlight the evolution of the last glacial-interglacial transition and the Holocene climate instabilities. The abundance data of species like Globorotalia truncatulinoides, Orbulina universa and Globigerinella siphonifera, which are considered warm-water indicators, and the variations of species like Globorotalia scitula, Turborotalita quinqueloba and Globigerinita uvula, which indicate cold-water conditions, have been analysed. Among calcareous nannofossils the abundance data of species like Syracosphaera pulchra, Rhabdosphaera clavigera and Helicosphaera carteri, which are considered subtropical species, and the variations of the cold-water species as Coccolithus pelagicus and Gephyrocapsa mullerae have been used. Benthic assemblages have been used for the bottom paleoenvironmental reconstruction and paleobathymetry curves have been reconstructed on the polynomial analysis of ostracoda assemblages.
References Amore F.O.,Ciampo G.,DiDonato V.,Esposito P.,Ermolli E.& Staiti D.2000-An integrated micropaleontological approach applied to Late Pleistocene-Holocene paleoclimatic changes(Gaeta Bay,Italy).Royal Geol. Soc.,special issue,London,95-111. Buccheri G.,Capretto G.,Di DonatoV.,Esposito P.,Ferruzza G.,Pescatore T. Russo Ermolli E., Senatore M.R.,Sprovieri M.,Bertoldo M.,Carella D.,Madonna G.,2002.A high resolution record of the last deglaciation in the south Tyrrhen ian Sea:environmental and climatic evolution. Mar. Geol.186, 447-470.
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