5:15 PM - 6:30 PM
[BPT05-P15] The origin of deep-sea sediments within the Minamitorishima EEZ inferred from elemental composition and isotopic ratios
Keywords:Deep-sea sediments, Rare Earth Sediments and Yttrium, Minamitorishima EEZ, Nd isotpes
In order to unravel the origin of these sediments, it is necessary to decipher geochemical end-members characterized by distinctive compositions and to specify their sources, fluxes and processes of supply. The most powerful tool for this approach is isotopic compositions such as Nd, Sr, Pb and so on. [3, 4].
Here, as the first step for the comprehensive elucidation of the origin of the deep sea sediments in the Minamitorishima EEZ, we analyzed the modern, uppermost sediment samples collected from the southern part of the Minamitorishima EEZ. We investigated (1) mineralogical compositions by smear slide observation and XRD analysis and (2) bulk chemical compositions by XRF and ICP-MS analyses, in addition to (3) bulk Nd isotopic ratios using Thermal Ionization Mass Spectrometry (TIMS). We report the results and interpretation of the analysis, and discuss the origin of the uppermost sediments in the study area.
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