Didie, Claudia and Bauch, Henning A. (2002) Implications of upper Quaternary stable isotope records of marine ostracodes and benthic foraminifera for paleoecological and paleoceanographical investigations. In: The Ostracoda: Applications in Quaternary Research. ; 131 , ed. by Holmes, J. A. and Chivas, A. R.. Geophysical Monograph, 131 . AGU (American Geophysical Union), Washington D.C., pp. 279-299.

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Abstract

A sediment core, covering marine isotope stage (MIS) 7 to I, and several urface
sediment samples, all from the Iceland Plateau, were investigated for deep- ea ostracode
carbon and oxygen isotopes. In contrast to the benthic foraminiferal species
Cibicidoides wuellerstorfi and Oridorsalis umbonatus, which both di play well-known
negative off ets from the oxygen isotope value of the equilibrium calcite, the investigated
ostracode genera Krithe and Henryhowella reveal positive offsets. We calculated an
offset of about+ 1.4 %o for Krithe and about +0.4 %o for Henryhowella with respect to
the equilibrium calcite. Downcore isotope analyses revealed differences between the
oxygen i otope records of the infaunai-Iiving foraminiferal species 0 . umbonatus and
the epifaunal-living species C. wuellerstorfi during periods of increa ed deposition of
IRD (iceberg rafted debris). These differences between infaunal and epifaunal oxygen
isotope signals have been recognized before within the area of the Nordic Seas and were
likely caused by environmental conditions during late MIS 6 and MIS 2, affecting
mainly the epifaunal-living taxa. The oxygen isotope record of Henryhowella reveal the
same trend as the record of C. wuellerstorfi, whereas the oxygen i otope records of
Krithe and 0 . wnbonatus are parallel to each other. This sugge ts an epifaunal habitat
for Henryhowella and an infaunal habitat for Krithe, which is in agreement with the
faunal abundance data as well as with other ostracode studie . The carbon isotope
records of Henryhowella and 0. umbonatus display a globally ob erved trend of
low o''C values during the glacial and high value during the interglacial periods,
whereas the one record of Kritlze shows no such climate-related trend, probably due to
strong vital effects.

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