Marine Thalassiosira species from coastal Pleistocene sediments in central Kanto Plain, Japan

Abstract

Nineteen species of the diatom genus Thalassiosira Cleve, including two tentatively identified and three unidentified species, are recorded from two sediment cores, drilled in Pleistocene coastal sediments of the Kanto Plain, central Japan. Concise descriptions obtained from the light and scanning electron microscopes are provided for the 19 Thalassiosira taxa recorded. This is the first study systematically investigating the taxonomy of the genus Thalassiosira and detailing the stratigraphic distribution of each taxon from Pleistocene coastal sediments of Japan. The species diversity of the genus Thalassiosira in the Japanese Pleistocene coastal environment is as high as in recent coastal waters.

Keywords:

• fossil diatoms
• Kanto Plain
• Japan
• drill core
• marine coastal sediments
• Pleistocene
• Thalassiosira

Acknowledgements

I am grateful to Yukio Yanagisawa from the Institute of Geology and Geoinformation, National Institute of Advanced Industrial Science and Technology (AIST) for his valuable suggestions and discussions on the manuscript. Thanks are also due to Shoich Hachinohe from the Center for Environmental Science in Saitama (CESS) allowing the author to use the core samples owned by CESS, Misao Hongo of AIST (currently at the Alps Technical Research Laboratory Co., Ltd.) and Masaaki Yamaguchi of AIST (currently at the Quintessa Limited K.K.) for their assistance in sample collection, and Kiyohide Mizuno of AIST for his helpful comments on stratigraphy. Special thanks are expressed to A.J. Martin of the National Cooperative for the Disposal of Radioactive Waste for reading the manuscript and his suggestions to improve the English. Special thanks also to the associate editor and anonymous reviewers for their helpful suggestions to the manuscript. This work was partly supported by Special Coordination Funds for Promoting Science and Technology (project: Development of Integrated Geophysical and Geological information Database) from Japan Science and Technology Agency.

Additional information

Notes on contributors

Tomonori Naya

Supplementary data available online at www.tandfonline.com