Japan Geoscience Union Meeting 2014

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Symbol H (Human Geosciences) » H-QR Quaternary research

[H-QR23_1AM2] Diachronic dynamics of human-environment interactions

Thu. May 1, 2014 11:00 AM - 11:30 AM 414 (4F)

Convener:*Takahiro Miyauchi(Department of Earth Sciences, Graduate School of Science, Chiba University), Toshihiko Sugai(Department of Natural Environmental Studies, Institute of Environmental Studies, Graduate School of Frontier Science, The University of Tokyo), Takashi AZUMA(Active Fault and Earthquake Research Center, National Institute of Advanced Industrial Science and Technology), Akira Ono(Meiji University Center for Obsidian and Lithic Studies), Chair:Osamu Fujiwara(Active Fault and Earthquake Research Center, National Institute of Advanced Industrial Science and Technology)

11:15 AM - 11:30 AM

[HQR23-P07_PG] Morphosis of the Oyster shell bed and Diatom assemblage in Tokyo bay

3-min talk in an oral session

*Marie NOGUCHI1, Kunihiko ENDO2, Kaoru KASHIMA1 (1.Kyushu University, 2.Nihon University)

Keywords:Tokyo bay, oyster shell bed, diatom

Recently, oyster shell beds and reefs have been found in various places in Tokyo bay. Six shell bed types can be recognized on the basis of their lithology (YOKOYAMA et.al., 2004). Topographic and paleogeographic changes closely related to the Holocene Jomon Transgression, have been investigated by reconstructing the migration of oyster shell beds, which are good markers of paleoshorelines, throughout the wide inner bay during the rising stage of sea-level. However, ecology of benthos and diatom assemblages is not clear about oyster shell bed types(Endo et.al.,2013 ). This study describes taphonomic processes of the oyster reefs well exposed in Tokyo bay, Sanbanze. The oyster reefs of Sanbanze have grown up during about 5 years. The growth of oyster reefs was rapid but nowadays it is reduced due to change of oyster environment as consequences of Torrential rain and Typhoon. We started to do research 5 years ago in Sanbanze. We are making a report on oyster shell bed types and ecology of diatom assemblage in this area.