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Figure F20. Micropaleontological age datums and rank abundance of important biostratigraphic diatom and radiolarian indicators, shown as a composite from Holes U1417A–U1417E. Composite diatom biostratigraphy shows relative abundance (%) of eight diatom species (Neodenticula seminae, Proboscia curvirostris, Proboscia barboi, Actynocyclus oculatus, Neodenticula koizumii, Neodenticula kamtschatica, Shionodiscus oestrupii, and Stephanopyxis horridus). Composite radiolarian biostratigraphy shows relative abundance (%) of ten radiolarian species (Lynchnocanoma sakaii, Axoprunum acquilonium, Stylaconturium universus, Eucyrtidium matuyamaii, Sphaeropyle robusta, Cycladophora sakaii, Cycladophora davisiana, Thecosphaera akitaensis, Phormocyrtis fistula, and Thecosphaera pseudojaponica). NPD = Neogene North Pacific Diatom zone of Yanagisawa and Akiba (1998). FO = first occurrence, LO = last occurrence.

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