Holocene benthic foraminifera from Bahía Blanca estuary: a review and update of systematic and palaeoenvironmental aspects

CUSMINSKY GABRIELA; BERNASCONI EMILIANA; CALVO MARCILESE LYDIA

HOLOCENE (SEVENOAKS)

SAGE PUBLICATIONS LTD

Lugar: United Kingdom; Año: 2009 vol. 19 p. 1221 - 1231

0959-6836

Assemblages of benthic foraminifera in a Holocene core from the outer area of Bahía Blanca estuary in Argentina were studied. The systematics of the group was updated, and the main species recorded were Buccella peruviana f. campsi (Boltovskoy), Ammonia beccarii (Linné), Elphidium gunteri Cole, Elphidium galvestonense Kornfeld, Elphidium articulatum d´Orbigny and Elphidium discoidale (d´Orbigny). These species allowed an estuarine environment to be determined. Qualitative and quantitative studies conducted on the faunistic content in the core allowed identification of three sub-environments closely linked to sea level fluctuations during the mid-Holocene: a lower zone (6350 years BP) corresponding to a high intertidal zone, an intermediate zone (2460 years BP) representing a low intertidal zone related to a system of channels and variations in environmental energy, and an upper zone characterized by the development of a high-energy littoral environment affected by the action of waves, tides and tidal currents, which underwent progressive change until it attained present-day conditions.