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Detailed study of associations of planktonic foraminifera in cores MD95-2043 and ODP 977, located in the Alboran Sea (Mediterranean Sea), has allowed the identification of 29 new faunal events, defined by abrupt changes in the abundances of Neogloboquadrina pachyderma (right and left coiling), Turborotalita quinqueloba, Globorotalia scitula, Globorotalia inflata, Globigerina bulloides and Globigerinoides ruber (white and pink varieties). The age model for ODP 977 was based on that of MD95-2043 [Cacho et al. (1999), Paleoceanogr. 14, 698–705], on the isotopic stratigraphy, and on two AMS 14C measurements. Sea Surface Temperatures (SSTs) were estimated for the last 54 kyr using the Modern Analog Technique (MAT) and were compared with the SSTs provided by the Uk′37 method. The Uk′37 record is very similar to the MAT annual mean temperature record for the last 8 kyr. However, for older times alkenone-derived temperatures are consistently higher than the annual MAT temperatures. This offset may be due to an underestimation of the SST provided by the planktonic foraminiferal method for glacial times, to an overestimation of the Uk′37 record, or to changes in the seasonal production of alkenones. Most of the variability in the fauna is related to the millennial variability of Heinrich and Dansgaard–Oeschger (D–O) events. During Heinrich events (HEs) and most of the other D–O stadials, G. bulloides, T. quinqueloba and G. scitula increased, while N. pachyderma (right coiling), G. inflata and G. ruber decreased. By contrast, N. pachyderma (left coiling) was only abundant in the HEs. The main component of the associations – N. pachyderma (right coiling) – follows a general trend similar to that of sea-level and δ18O. This species reached its highest abundance during the Last Glacial Maximum, when sea-level was at a lower position. The occurrence of a shallower nutricline owing to a shallowing of the interface between Atlantic inflowing and Mediterranean outflowing waters could have favoured the development of neogloboquadrinids in the vicinity of the Strait of Gibraltar. [Copyright &y& Elsevier]

Abstract: The present work analyses the seasonal evolution of planktonic assemblages and particle fluxes through the water column in the Eastern Alboran Sea (Western Mediterranean) at 35º55.47''N/01º30.77''W. A Sediment trap was deployed below the influence of the Almeria-Oran Front (AOF), a semi-permanent geostrophic front, during July 1997 to June 1998. Overall, the temporal variability of coccolithophore, planktonic foraminifer, diatom, benthic and wind-carried biogenic particle fluxes is linked to the seasonal evolution of sea surface hydrological structures. Maximum planktonic fluxes were found during high-productivity periods and wind-induced upwelling, following a trimodal pattern, with maximum fluxes in July 1997, November–December 1997, and April–May 1998. These periods were characterized by vertical mixing and the full development of anticyclonic gyres in the Alboran Sea. The annual flux of coccolithophores was dominated by the “small Gephyrocapsa Group” and Emiliania huxleyi, whereas Turborotalita quinqueloba and Globigerina bulloides dominated the foraminiferal fluxes, and Chaetoceros Resting Spores (RS) were predominant in the diatom assemblage. Benthic specimens were also collected with the sediment trap, suggesting a variable influence of bottom water activity. Wind-driven particles (phytoliths and fresh-water diatoms) were collected along the year, but their fluxes followed the local wind regime. The high Sea Surface Temperature (SST) during fall due to weaker than usual westerly winds, and the pressure anomaly prevailing in the Alboran Sea during early winter, were reflected in the planktonic assemblages by the proliferation of warm, lower photic layer inhabitants and/or oligotrophic taxa of coccolithophores (Florisphaera profunda), planktonic foraminifers (Globigerinoides ruber and Globorotalia inflata) and diatoms (Leptocylindrus danicus). These unusual climatic conditions in the eastern Alboran Sea must have been caused by the 1997–1998 ENSO event. [Copyright &y& Elsevier]