In this study, variations of organic carbon accumulation rate in hemipelagic mud during the end of last glacial period to deglaciation were examined in the two different depositional environments in the forearc basins along the Nankai Trough, such as on the deep-sea fan which connected submarine canyon and deep-sea floor where is far from the canyon mouth. The sediment of deep-sea fan contained several turbidite layers during the end of last glacial period, and the depositional frequencies of turbidites were decrease with sea-level rise during the deglaciation. On the other hand, turbidites were not recognized in the deep-sea floor sediments that were deposited far from the submarine canyon. The accumulation rate of organic carbon and terrigenous contents were high during the end of last glacial period, while those were low and the most of organic carbon is marine origin in the both depositional environments during the deglaciation.

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The Pliocene to Middle Pleistocene Kazusa Group is widely distributed in subsurface of the Kanto Plain, central Japan. This study analyzed two drilling cores CRE-TAT-1 and CRE-TAT-2 obtained from the Fuchu city, Tokyo, where is located on the Tachikawa surface of Musashino uplands (terrace), the western part of Kanto Plain. The lithology and sedimentary structures of these cores were characterized in detail and grain-size distributions, water content, electrical conductivity and pH values in soil-stirred water were measured. Also, diatom assemblage analysis and X-ray fluorescence analysis were carried out. Both cores are divided into unit 1 to unit 7, in ascending order. Unit 1 is sandy channel and floodplain sediments. Unit 2, 4, and 6 are sandy gravels of river channels. Unit 3 consists of sand and silt with fresh-water diatom indicating floodplain environments. Unit 5 has sandy channel sediments at the bottom. The middle part of the unit 5 is bluish gray silt with abundant marine diatom. High sulfur content and electric conductivity suggest marine environment. It coarsens upward into the sandy channel and floodplain sediments showing upward shallowing trend.
Unit 1 to 5 might correspond to the Toneri formation of the Kazusa Group deposited during 1.219-0.78 Ma. Unit 6 is terrace gravel which forms the Tachikawa surface during 0.4-0.2 Ma, and unit 7 is the Tachikawa Loam.

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