Recent microfauna and -flora in the Gulf of Cadiz and W off Portugal; a key to the history of the Mediterranean Outflow Water (IODP Expedition 339)

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Author(s): Grunert, Patrick; Balestra, Barbara; Hodell, David; Flores, José-Abel; Alvarez-Zarikian, Carlos; Hernández-Molina, Javier; Stow, Dorrik
Integrated Ocean Drilling Program, Expedition 339 Scientists Team, College Station, TX
Author Affiliation(s): Primary:
University of Graz, Institute for Earth Sciences, Graz, Austria
Queens College, United Kingdom
University of Cambridge, United Kingdom
University of Salamanca, Spain
Universidad de Vigo, Spain
Heriot-Watt University, Edinburgh, United Kingdom
Volume Title: European Geosciences Union general assembly 2013
Source: Geophysical Research Abstracts, Vol.15; European Geosciences Union general assembly 2013, Vienna, Austria, April 7-12, 2013. Publisher: Copernicus GmbH on behalf of the European Geosciences Union (EGU), Katlenburg-Lindau, Germany. ISSN: 1029-7006
Note: In English
Summary: IODP Expedition 339 recently drilled 5 sites in the Gulf of Cádiz and 2 west off Portugal, and recovered 5.5 km of core. The Gulf of Cadiz was targeted for drilling 1) to investigate the Mediterranean Outflow Water (MOW) and its influence on global circulation and climate, and 2) to understand the effects of tectonic activity and eustatic changes on evolution of the Gibraltar Gateway and margin sedimentation. During the expedition samples from surface-waters and the seafloor were collected to evaluate recent communities of foraminifers, ostracods and calcareous nannoplankton. The results will serve as an important reference for future paleoceanographic work based on the actualistic approach in the Upper Miocene-Pleistocene deposits drilled during IODP Expedition 339. Over 400 foraminiferal taxa have been identified in size fractions >125 m at six sites of IODP Expedition 339. The preliminary results show that living specimens are rare (1-5% of the assemblages), which is most likely related to deep-sea patchiness; loss during the drilling process cannot be excluded for some samples. The composition of live and dead assemblages strongly depends on water depth and position along the pathway of MOW. Statistical analysis indicates the distinction of three groups of foraminiferal assemblages that reflect the influence of the upper and lower cores of MOW, and North Atlantic Deep Water. Combined with ostracod and nannoplankton assemblages the results will provide insights into the effect of spatial and vertical fluctuation of North Atlantic Deep Water, Antarctic Intermediate Water and MOW circulation on the microfauna and -flora. Moreover, δ13C, δ18O, Mg/Ca and Sr/Ca of foraminifers, ostracods and coccoliths will be determined and compared to seawater geochemistry to evaluate "vital effects". [Copyright Author(s) 2013. CC Attribution 3.0 License:]
Year of Publication: 2013
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 07 Marine Geology and Oceanography; Atlantic Ocean; Ecology; Expedition 339; Gulf of Cadiz; Integrated Ocean Drilling Program; Marine sediments; Microorganisms; North Atlantic; Ocean circulation; Sediments
Coordinates: N361605 N373418 W0064700 W0100735
Record ID: 2018100182
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from European Geosciences Union, Munich, Germany