Tracing the sediment provenance in the Bellingshausen Sea for the changes of the West Antarctic Ice Sheet

Previously, clay mineral assemblages are frequently used to understand the sediment provenances. However, clay mineralogy may not be sufficient to prove the source of sediments, because even same clay mineral, for example smectite has various chemical composition that may have multi sediment sources. Such that elemental composition of smectite at a nano scale is necessary to confirm clearly the source of sediment. Clay mineralogy, elemental composition and crystal size distributions (CSDs) of smectite from the Bellingshausen Sea was investigated to puzzle out the sediment provenance that was not compatible with clay assemblages. We will test sediments for the sampling site (BS17-GC04, BS17-GC15) that may be affected by various sediment sources from the Ronne Entrance and Beethoven Peninsula, Bellingshausen Sea. Clay size fraction less than 2 mm was used to measure the mineralogy and semi-quantification analysis with depth by X-ray diffractometer (XRD). Smectite, illite, chlorite and kaolinite are dominant phase in sediments. The proportional variation of clay minerals with depth corresponds to the glacier movement. Crystal size distributions and elemental composition of clay mineral using TEM verify the origin of sediments during glacial and interglacial period. New approach to define the source of sediments will be discussed.