Holocene benthic foraminifera from Bahia Blanca estuary: a review and update systematic and paleeoenvironmental aspects.

CUSMINSKY, G,; BERNASCONI, E.; CALVO MARCILESE, L

HOLOCENE (SEVENOAKS)

Arnold

Año: 2009 vol. 19 p. 1221 - 1231

0959-6836

Abstract: Assemblages of benthic foraminifera in a Holocene core from the outer area of Bahía Blanca estuaryin Argentina were studied. The systematic of the group was updated, and provided 28 genera distributed among59 species, six species with nomenclature aperta. 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 estuarineenvironment to be determined. Qualitative and quantitative studies conducted on the faunistic content in thecore allowed identification of three subenvironments closely linked to sea-level fluctuations during the midHolocene: a lower zone (6350 yr BP) corresponding to a high intertidal environment, an intermediate zone(2460 yr BP) representing a low intertidal environment related to a system of channels and variations in envi-ronmental energy, and an upper zone characterized by the development of a high-energy littoral environmentaffected by the action of waves, tides and tidal currents, which underwent progressive change until it attainedpresent-day conditions.