| Project/Area Number |
09640559
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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 | Osaka City University |
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Principal Investigator |
YAO Akira Faculty of Science, Osaka City University, Professor, 理学部, 教授 (40047353)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 1998: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1997: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Keywords | radiolaria / Jurassic / Paleo-Pacific / 放散虫化石 / 海洋環境変動 |
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| Research Abstract |
This project had a subject to consider the change of oceanic environment in the northwestern Paleo-Pacific during Jurassic time. The data based on Jurassic radiolarian faunas were gotten from the Jurassic accretionary complexes of the Tanba-Mino and Chichibu terranes in southwest Japan. The radiolarian research was focused on the faunal analysis by means of identification of whole species occurred from each samples.
It was clarified that the specific number of radiolarian fauna was decreased around the Triassic/Jurassic boundary. This phenomenon is considered to be affected by the mass extinction event of Triassic/Jurassic boundary. The Toarcian event, which was represented by the oceanic anoxia, also affected the specific number of radiolarian fauna. Although the faunal change of radiolarians was slow from middle Toarcian to early Aalenian time, it was fast from late Aalenian to Bajocian time. This phenomenon may be related to the change of oceanic environment caused by the development of Central Atlantic Seaway.
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