2005 Fiscal Year Final Research Report Summary
Miocene paleoceanography around the North Pacific based on the activities of past primary producers and benthic organisms
| Project/Area Number |
15540448
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Stratigraphy/Paleontology
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| Research Institution | Chiba University |
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Principal Investigator |
KAMEO Koji Chiba University, Marine Biosystems Research Center, Assistant professor, 海洋バイオシステム研究センター, 助手 (00312968)
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| Co-Investigator(Kenkyū-buntansha) |
KOTAKE Nobuhiro Chiba University, Faculty of Sciences, Associate professor, 理学部, 助教授 (00205402)
MOTOYAMA Isao Tsukuba University, Department of Earth Sciences, lecturer, 地球科学系, 講師 (80295295)
IWAI Masao Kochi University, Faculty of Sciences, Associate professor, 理学部, 助教授 (90274357)
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| Project Period (FY) |
2003 – 2005
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| Keywords | calcareous nannofossils / diatoms / radiolarians / trace fossils / calcareous concretion |
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| Research Abstract |
The qualitative analyses of microfossils and trace fossils from the Neogene and the Quaternary sections distributed in the Pacific side of Japan and related deep sea core sediments were performed to determine changes in surface circulation systems in the North Pacific and changes of deep sea environments, and implications for climatic changes. Stratigraphic occurrences of two characteristic taxa of nannofossils and diatoms in the Choshi area allow us to monitor the movement of the oceanographic front around the NW Pacific. Floral changes can be strongly related to the circulation changes around the North Pacific Ocean. For example, at approximately 0.85 Ma, the Oyashio Current, a cool and nutrient-rich surface current in the NW Pacific, suddenly invaded into the Pacific side around the Japanese islands. The timing of this strong invasion of the Oyashio Current coincides with the initial event of the mid-Pleistocene Transition (MPT;0.90〜0.60Ma), corresponding to the transition time to high frequnecy ice volume fluctuation during the late Pleistocene (e.g.Raymo,1990). This means that the oceanographic frontal system along the NW Pacific has been controlled by global climate change occurred in the high latitude during the middle Pleistocene. At the same time, activities of benthic organisms and developments of calcareous concretion layers had become stronger and thus, these results suggest that the subtropical gyre circulation in the North Pacific region had changed and deep sea circulations also altered. During the Miocene, same phenomena were also found and thus, flux changes of primary producers affected ocean climatic changes.
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Research Products
(12 results)
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[Journal Article] Origin of remanent magnetization and magneto-biostratigraphy correlation in pelagic sediments, ODP Site 1225, eastern equatorial Pacific.2005
Author(s)
Niitsuma, S., Ford, K., Iwai, M., Chiyonobu, S., Sato, T.
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Journal Title
Proc. ODP, Scientific Results 201(CD-ROM)
Description
「研究成果報告書概要(和文)」より
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[Journal Article] U-series ages for solitary coral species from the Middle Pleistocene Kunosan Formation in the Udo hills, Shizuoka, central Japan.2005
Author(s)
Kitamura, A., Omura, A, Tominaga, E, Kameo, K, Nara, M.
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Journal Title
The Quaternary Research (Daiyonki-kenkyu) 44
Pages: 177-182
Description
「研究成果報告書概要(和文)」より
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[Journal Article] Origin of remanent magnetization and magneto-biostratigraphy correlation in pelagic sediments, ODP Site 1225,eastern equatorial Pacific.2005
Author(s)
Niitsuma, S., Ford, K., Iwai, M., Chiyonobu, S., Sato, T.
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Journal Title
Proc.ODP, Scientific Results 201(CD-ROM)
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] U-series ages for solitary coral species from the Middle Pleistocene Kunosan Formation in the Udo hills, Shizuoka, central Japan.2005
Author(s)
Kitamura, A., Omura, A., Tominaga, E., Kameo, K., Nara, M.
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Journal Title
The Quaternary Research (Daiyonki-kenkyu) 44
Pages: 177-182
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Glacial-interglacial surface water variations in the Caribbean during the last 300 by based on calcareous nannofossil analysis2004
Author(s)
Kameo, K., Shearer, M.C., Droxler, A.W., Mita, I., Watanabe, R., Sato, T.
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Journal Title
Palaeogeogr., Palaeoclimatol., Palaeoecol. 212
Pages: 65-76
Description
「研究成果報告書概要(和文)」より
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[Journal Article] Glacial-interglacial surface water variations in the Caribbean during the last 300 ky based on calcareous nanofossil analysis.2004
Author(s)
Kameo, K., Shearer, M.C., Droxler, A.W., Mita, I., Watanabe, R., Sato, T.
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Journal Title
Palaeogeogr., Palaeoclimatol., Palaeoecol. 212
Pages: 65-76
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Age model, physical properties and pale oceanographic implications of the upper Quaternary core sediments in the Choshi area, central Japan
Author(s)
Komeo, K., Okada, M., El-Masry, M., Hisamitsu, T., Saito, S., Nakazato, H., Ohkohchi, N., Ikehara, M., Yasuda, H., Kitazato, H., Taira, A.
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Journal Title
Description
「研究成果報告書概要(和文)」より
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[Journal Article] Age model, physical properties and paleoceanographic implications of the upper Quaternary core sediments in the Choshi area, central Japan
Author(s)
Kameo, K., Okada, M., El-Masry, M., Hisamitsu, T., Saito, S., Nakazato, H., Ohkohchi, N., Ikehara, M., Yasuda, H., Kitazato, H., Taira, A.
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Journal Title
Description
「研究成果報告書概要(欧文)」より
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