HR: 09:00h
AN: PP41E-05 INVITED    [Abstracts]
TI: High Quality Proxy Data From Foraminiferal Calcite Using Flow-Through Time Resolved Analysis
AU: * Klinkhammer, G P
EM: gklinkhammer@coas.oregonstate.edu
AF: Oregon State University COAS, Ocean Admin Bldg 104, Corvallis, OR 97331, United States
AU: Mix, A C
EM: amix@coas.oregonstate.edu
AF: Oregon State University COAS, Ocean Admin Bldg 104, Corvallis, OR 97331, United States
AU: De Baere, B J
EM: bdebaere@coas.oregonstate.edu
AF: Oregon State University COAS, Ocean Admin Bldg 104, Corvallis, OR 97331, United States
AU: Haley, B A
EM: bhaley@ifm-geomar.de
AF: Leibniz-Institute of Marine Sciences, IFM-GEOMAR, Kiel, D-24148, Germany
AB: Flow through time resolved analysis (FT-TRA) offers increased potential over standard batch methods for extracting pristine El/Ca ratios from biogenic calcite, even in samples that are severely overgrown. The potential of the technique is rooted in its ability to resolve differences in solubility by making thousands of determinations (typically 8300) during the leaching and dissolution process. These time-resolved ratios can be used to isolate shell material from other phases and provide a real measure of uncertainties in the proxy. FT-TRA is based on the premise that biogenic calcite is one of the most soluble phases in a sample of foraminiferal tests and early methods were successful at dissolving carbonate phases while leaving more resistant phases like clays and low-Sr barite behind. More recent FT methods use deionized water and dilute nitric acid (3mM) along with highly controlled concentration gradients and flow-rate protocols to achieve improved resolution. Previous work has shown that FT-TRA dissolves different shell parts in the same sequence that occurs naturally on the sea floor. The natural formulation of FT-TRA yields insight into the formation, preservation and dissolution of biogenic calcite and associated authigenic minerals in addition to producing high quality proxy data. Examples of FT-TRA separations and their use in paleoceanography will be given in this presentation.
DE: 4912 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 1615, 4805)
DE: 4924 Geochemical tracers
DE: 4926 Glacial
DE: 4936 Interglacial
DE: 4994 Instruments and techniques
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting