HR: 14:25h
AN: B43G-03    [Abstracts]
TI: Coccolith Chemistry: A Flow-Through Analysis
AU: * Halloran, P P
EM: paul.halloran@earth.ox.ac.uk
AU: Rickaby, R
EM: rosr@earth.ox.ac.uk
AF: Department of Earth Sciences, Oxford University, Parks Road, Oxford, OX1 3PR, United Kingdom
AU: Myhra, S
EM: sverre.myhra@materials.oxford.ac.uk
AF: Department of Materials, Oxford University, Oxford University Begbroke Science Park, Sandy Lane, Yarnton, Kidlington, Oxford, OX5 1PF, United Kingdom
AB: Coccoliths not only hold much promise as a source of new and exciting geochemical data, but also provide an elegant test case for models of biomineral trace-metal incorporation due to their simple construction. Coccoliths are formed from a small number of single crystals growing from a ring of alternating vertical and radially oriented calcite nucleation sites. Microprobe and electron backscatter analysis hint at crystallographically discrete trace metal distribution coefficients. Here we investigate inhomogeneities within the calcite of coccolithophore monocultures using continuous-dissolution trace-metal analysis, combined with repeated AFM imaging of individual dissolving coccoliths. We present coccolith trace-metal distribution coefficients, explore the potential of coccolith calcite as a recorder of palaeoenvironmental data, and consider crystallographic controls over trace- metal chemistry.
DE: 0419 Biomineralization
DE: 0473 Paleoclimatology and paleoceanography (3344, 4900)
DE: 1051 Sedimentary geochemistry
DE: 1065 Major and trace element geochemistry
SC: Biogeosciences [B]
MN: 2007 Fall Meeting