HR: 17:30h
AN: B44C-06    [Abstracts]
TI: Environmental versus biological controls on multi-proxy records from bivalve shell carbonate
AU: * Hippler, D
EM: dorothee.hippler@falw.vu.nl
AF: Vrije Universiteit Amsterdam, Faculty of Earth & Life Sciences, De Boelelaan 1085, Amsterdam, 1081 HV, Netherlands
AU: Kluender, M H
EM: mhk@geus.dk
AF: Geological Survey of Greenland and Denmark (GEUS), ุster Voldgade 10, Copenhagen, 1350, Denmark
AU: Witbaard, R
EM: witbaard@nioz.nl
AF: Royal Netherlands Institute for Sea Research, P.O. Box 59, Den Burg, 1790 AB, Netherlands
AU: Buhl, D
EM: dieter.buhl@ruhr-uni-bochum.de
AF: Ruhr-University Bochum, Institute for Geology, Mineralogy and Geophysics, Universtitaetsstrasse 150, Bochum, 44780, Germany
AU: Richter, D
AF: Ruhr-University Bochum, Institute for Geology, Mineralogy and Geophysics, Universtitaetsstrasse 150, Bochum, 44780, Germany
AU: Frei, D
EM: df@geus.dk
AF: Geological Survey of Greenland and Denmark (GEUS), ุster Voldgade 10, Copenhagen, 1350, Denmark
AU: Immenhauser, A
EM: adrian.immenhauser@ruhr-uni-bochum.de
AF: Ruhr-University Bochum, Institute for Geology, Mineralogy and Geophysics, Universtitaetsstrasse 150, Bochum, 44780, Germany
AB: Field experiments on different bivalve species have been conducted in the Dutch Wadden Sea near the Netherlands Institute for Sea Research (NIOZ) to investigate the environmental and biological controls on the fractionation pattern of different stable isotope systems (¹⁸O/¹⁶O, ²⁶Mg/²⁴Mg, ⁴⁴Ca/⁴²Ca) and elemental/calcium ratios, and their reliability as geochemical proxies for high- resolution palaeoclimate reconstructions. Our study includes various individuals of the blue mussel, Mytilus edulis and juveniles of the ocean quahog, Arctica islandica. Our study is completed using samples from growth experiments on young Arcitca's which were also performed at the NIOZ laboratory. These individuals were cultured in five temperature controlled basins, ranging from 1 to 12° Celcius. The third sample set analysed was collected at several sites in the Baltic Sea characterised by salinities lower than 15 permil. Our data shows that both species deposit their shells in isotopic equilibrium with ambient seawater. Trace element ratios in Mytilus edulis further indicate that Mg/Ca may indeed provide a reliable palaeothermometer. In contrast, Calcium and magnesium isotope fractionation is obviously controlled by biological processes. However, environmental signals (e.g. temperature, salinity) are well recorded in the shells. Therefore, the combined approach could give new insights into biomineralization processes. This is a contribution to EuroCLIMATE project 04 ECLIM FP08 CASIOPEIA.
DE: 0419 Biomineralization
DE: 0454 Isotopic composition and chemistry (1041, 4870)
DE: 0460 Marine systems (4800)
DE: 1055 Organic and biogenic geochemistry
DE: 4954 Sea surface temperature
SC: Biogeosciences [B]
MN: 2007 Fall Meeting