[M-IS20] 遠洋域の進化

[MIS20-06] 新生代深海堆積物の地球化学データの多変量統計解析：顕生代を通じた遠洋域の進化の解読へ向けて

★招待講演

*安川 和孝^1,2、藤永 公一郎^2,1、中村 謙太郎¹、岩森 光^3,4、加藤 泰浩^1,2,3 (1.東京大学大学院工学系研究科、2.千葉工業大学次世代海洋資源研究センター、3.海洋研究開発機構、4.東京工業大学地球惑星科学系)

キーワード：深海堆積物、多変量解析、独立成分分析、付加体

Deep-sea sediments are important record media of the changes in global climate, tectonics, and geochemical cycles, both in the present and the past oceans. From a different point of view, a certain type of sediment is enriched in industrially critical metals and thus expected as a promising resource in near future. For the purpose of clarifying the origin(s) of rare-earth elements and yttrium (REY)-rich mud, we have constructed a huge dataset of bulk chemical composition of deep-sea sediments from more than 100 sites in the Pacific and Indian oceans. By applying a multivariate statistical technique called independent component analysis (ICA) to the hemisphere-scale dataset, we extracted statistically independent components (ICs) that characterize the geochemical signatures in the Cenozoic deep-sea sediments. Moreover, by combining the ICs with depositional ages and reconstructed plate motions, we visualized the spatiotemporal variations of the ICs over the past 65 million years (Yasukawa et al., 2016). In the presentation, we will discuss the potential for the extension of the multivariate statistical approach to the accretionary complex that records the oceanographic information older than the Cretaceous.