[O-02] Poster presentations by senior high school students

[O02-P06] Microfossils from the Nihon University Mutsuai Campus core, Fujisawa City, Kanagawa Prefecture

*Haruhi Imahashi¹, Yuka Sato¹, Arisa Matukura¹, Hitomi Saito¹, Yoshimi Honda¹ (1.Gunma Prefectural Ota girls' high school)

Keywords:ostracode, foraminifera, Fujisawa Mudstone, Paleo-Sagami Bay

Four sediment samples were collected from the Fujisawa Mudstone in the Nihon University Mutsuai Campus core, Fujisawa City, Kanagawa Prefecture, central Japan. This core was situated the middle part of Paleo-Sagami Bay developed during the interglacial period (MIS 5). In total, 26 ostracode species and 47 foraminiferal species were identified in four samples. The dominant ostracode species were Bicornucythere bisanensis, Neomonoceratina delicata and Trachyleberis ishizakii. The dominant foraminiferal species were Elphidium subgranulosum, Pseudorotalia gaimardii, Buccella frigida, Elphidium advenum and Murrayinella minuta. These species are living in middle to outer bays. These data indicate that the depositional environment of the Fujisawa Mudstone at the study site was middle to outer bay area. In addition, the dominant four foraminiferal species were examined the ratio of dextral individuals and sinistral individuals. In the foraminiferal species of Ammonia japonica, M. minuta and P. gaimardii, there are more sinistral individuals than dextral individuals. On the other hand, the foraminiferal species of B. frigida, dextral individuals and sinistral individuals are almost the same number.