[HQR04-P04] Environmental change from diatom analysis since MIS7 to Jomon Transgression in the Omoikawa lowland and North Nakagawa lowland, the Kanto plain
Keywords:diatom analysis, Jomon Transgression, MIS5e, Kurihashi, Goka, Boring core
At the eastern side of Omoikawa and Nakagawa Lowlands, Koga terrace (MIS5a to MIS5e, Kaizuka et al., 2000) is situated, extending to Kurihashi. Goka terrace is very low terrace near Kurihashi. Tone River is going through Koga terrace and Goka terrace, by construction of the new cahnnel. At a result, topographical and geological conditions in Kurihashi and Goka areas are very complicated.
We analyzed the topography and geology in this area using many boring data. This shows the Goka terrace is composed of Joso F. (MIS5c) and marine mud of MIS5e below -14m. The latter may be the same horizon as C unit of Omoikawa core, which is characterized by inner-bay environment by diatom analysis.
From these, paleoenvironments during Inner-Tokyo Bay (MIS1) and Paleo-Tokyo bay (MIS7 to MIS5) , along with the basal topography of Chuseki-so will be discussed.