Glacial-interglacial variability in deep sea ostracod assemblage composition at IODP Site U1314 in the subpolar North Atlantic

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doi: 10.1016/j.margeo.2008.11.009
Author(s): Alvarez Zarikian, Carlos A.; Stepanova, Anna Yu.; Grutzner, Jens
Author Affiliation(s): Primary:
Integrated Ocean Drilling Program, College Station, TX, United States
Russian Academy of Sciences, Paleontological Institute, Russian Federation
Bremen University, Federal Republic of Germany
Volume Title: Marine Geology
Source: Marine Geology, 258(1-4), p.69-87. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0025-3227 CODEN: MAGEA6
Note: In English. Supplemental information/data is available in the online version of this article. 13 refs.; illus., incl. 2 tables, sketch map
Summary: We present a detailed study of glacial/interglacial deep sea benthic ostracod assemblage variability at IODP Site U1314 (subpolar North Atlantic) in relation to the history of ice-rafting events and changes in deep ocean circulation over the past 170 ky. Our records of ostracod diversity, abundance and dissolution and sediment properties (IRD and CaCO3) show an excellent correspondence to high amplitude orbital and millennial variability observed in the climate records (δ13C and δ18O) from neighboring deep water sites, suggesting that the benthic meiofauna fluctuates synchronously with the prevailing oceanographic conditions (surface ocean conditions, deep ocean circulation and water temperature and food flux). Krithe (dominant), Argilloecia and Cytheropteron are the most abundant and diverse genera in association with Rockallia enigmatica. Three ostracod assemblages are recognized. The genera Pennyella, Argilloecia, Pelecocythere, Ambocythere, Pseudobosquetina, Bradleya and Nannocythere are associated with interglacials and interstadials, and possibly reflect increased flux of food to the sediments and more vigorous NADW formation. A transitional assemblage composed of species of Cytheropteron, Xestoleberis and Eucythere is restricted to climatic transitions and indicate moderate environmental conditions and seasonal productivity. A glacial/stadial assemblage is characterized by a temporal predominance of either intermediate-depth and shallow water Arctic/subarctic species (belonging to Cytheropteron, Polycope, Pedicythere, Swainocythere, Cluthia, Heterocyprideis, Elofsonella and Finmarchinella) or abyssal North Atlantic ostracods (Bythocythere, Dutoitella, Bathycythere and Bythocypris). The influx of high latitude taxa can be partially explained by ice-rafting, but may also represent a shift of the location of intermediate and deep water convection to the area south of Iceland. Therefore the combination of species characteristic of different watermasses during glacials may reflect shifts in the influence of high nutrient southern source water (e.g. AABW) vs. low nutrient GNAIW during glacials. Abstract Copyright (2009) Elsevier, B.V.
Year of Publication: 2009
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Arthropoda; Assemblages; Atlantic Ocean; Benthic taxa; Biostratigraphy; C-13/C-12; Calcium carbonate; Carbon; Cenozoic; Chemostratigraphy; Cores; Correlation; Crustacea; Deep-sea environment; Depositional environment; Expedition 306; Glacial environment; IODP Site U1314; Ice rafting; Integrated Ocean Drilling Program; Interglacial environment; Invertebrata; Isotope ratios; Isotopes; Mandibulata; Marine environment; Marine sediments; Microfossils; North Atlantic; Northeast Atlantic; Ostracoda; Paleo-oceanography; Paleoclimatology; Paleoecology; Quaternary; Sediments; Stable isotopes; Subarctic regions; Upper Quaternary
Coordinates: N562200 N562200 W0275300 W0275300
Record ID: 2009052502
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands