Benthic and Planktic Foraminifera as Indicators of Late Glacial to Holocene Paleoclimatic Changes in a Marginal Environment: An Example from the Southeastern Bay of Biscay

• Authors: Jennifer Garcia , Meryem Mojtahid , Hélène Howa , Elisabeth Michel , Ralf Schiebel , Céline Charbonnier , Pierre Anschutz , Franciscus J. Jorissen
• Languages of publication: PL

Abstracts

PL

Benthic and planktic foraminiferal assemblages from two sediment cores (2000 m depth, 44°33′N-2°45′W) were analyzed to first compare modern and dead faunas and next to study changes in the hydrology of the southeastern Bay of Biscay (SE BoB) over the last 12.8 cal ka BP. Considering benthic ecosystem characteristics, the first part of the paleorecord (12.8–7.6 cal ka BP) is composed of laminated sediments that may have resulted from turbiditic overflow events, whereas occurrences of transported species (e.g. Nonionella sp., Cassidulina carinata) attest of continental influence at the core location. After 7.6 cal ka BP, the sediment becomes bioturbated concomitantly to the stabilization of the sea-level. The benthic foraminiferal fauna is largely dominated by Uvigerina peregrina suggesting a high seasonality with seasonal pulsed organic matter fluxes to the seafloor. On the other hand, the planktic foraminiferal composition indicates that surface water masses were under the influence of the polar front in the early record, which retreated at about 11.5 cal ka BP. The early Holocene is characterized by relatively warm and stratified water masses at 8.4–4.8 cal ka BP. The last 4.8 cal ka BP records a gradual sea surface water cooling trend and enhanced foraminiferal production from ~2.6 cal ka BP until present. The early (12.8–10.5 cal ka BP) and late (2.3–1.7 cal ka BP) Holocene are characterized by the presence of the planktic species Globigerinoides ruber probably caused by intrusions of the Iberian Poleward Current (IPC), and a negative state of the North Atlantic Oscillation (NAO).

Keywords

PL

Benthic Foraminifera, Planktic Foraminifera, Stable isotopes, Bay of Biscay, Holocene, Iberian Poleward Current (IPC)

• Publisher: Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
• Journal: Acta Protozoologica
• Year: 2013
• Volume: 52
• Issue: 3

Dates

published

2013

online

07 - 09 - 2015

Contributors

author

Jennifer Garcia

author

Meryem Mojtahid

author

Hélène Howa

author

Elisabeth Michel

author

Ralf Schiebel

author

Céline Charbonnier

author

Pierre Anschutz

author

Franciscus J. Jorissen