⁵⁷Fe Mössbauer Study of Specific Iron Species in the Antarctic Ocean Sediments

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To elucidate the environment of sedimentation in the Scotia and Ross Seas in the Antarctic Ocean during the period from upper Pleistocene to the present, sediments from the seas were investigated by ⁵⁷Fe Mössbauer spectroscopy, instrumental neutron activation analysis, and X-ray absorption near-edge structure. In Mössbauer spectra of Scotia Sea sediment, a specific doublet peak (isomer shifts of 0.57–0.59 mm s^-1, quadrupole splitting of 1.70–1.83 mm s^-1) was observed, suggesting the generation of primary glauconite by detailed speciation. In contrast, sediment cores from the Ross Sea and another sea area around Antarctica had no specific peak in Mössbauer spectra. Concentrations of iron and other elements in both sediments hardly fluctuated, that is, sedimentation matter in the Scotia Sea sediments containing iron species was not affected by the origin of specific iron species but by factors such as early-stage diagenesis.