| Project/Area Number |
16204040
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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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 | The University of Tokyo |
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Principal Investigator |
ISOZAKI Yukio The University of Tokyo, Dept. Earth Science & Astronomy, Professor (90144914)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUO Motoyuki University Tokyo Komaba, Dept. Chemistry, Professor (10167645)
KAWAHATA Hodaka University Tokyo Komaba, Dept. Marine Chemistry, Professor (20356851)
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| Project Period (FY) |
2004 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥47,060,000 (Direct Cost: ¥36,200,000、Indirect Cost: ¥10,860,000)
Fiscal Year 2007: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000)
Fiscal Year 2006: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2005: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2004: ¥33,670,000 (Direct Cost: ¥25,900,000、Indirect Cost: ¥7,770,000)
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| Keywords | mass exticntion / P-T boundary / G-L boundary / carbon isotope ratio / Sr isotope ratio / Permian / Kamura event / plume winter / Capitanian / 古生代 / 光合成共生 / 巨大二枚貝 / 寒冷化 / 海山 / 共生 / X線マイクロアナライザー / 微量元素組成 / 超海洋中央部 |
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| Research Abstract |
During the 4 years of research under the support of this grant-in-aid, we conducted field studies in the northern Sichuan in China, central Kyushu in Japan, and the Velebit mountains in Croatia, and in door geochemical analyses. These led the following results and conclusions.
1) An unusually high positive values of carbon isotope ratio was detected for the first time from a 5 million years interval immediately before the G-L boundary mass extinction. We named this unique event of a global context the "Kamura event" after the study area in Kyushu. This implies the increase in primary productivity in the superocean, mass consumption of atmospheric C02, decline in greenhouse effect, and resultant global cooling.
2) The simultaneous extinction of the Guadalupian shallow marina fauna composed of gigantic bivalves (Alatoconchidae), large-tested fusulines and rugose corals was documented both in Tethys and the superocean Panthalassa. These "tropical trio" shared the same habit of photosymbiosi
… More
s with algae/bacteria under oligtrophic environments, and they were terminated probably by cooling through the collapse of photosymbiosis.
3) We confirmed that the Sr-isotope ratio reached the minimum of the Phanerozoic in the late Guadalupian. This apparently coincided with the greatest sea-level drop in the Phanerozooic. These indicate the end-Guadalupian event was related to the initial Pangean breakup in the late Middle Permian.
4) We found that the P-T boundary interval in South China is characterized by frequent activity of felsic (explosive) volcanism. Geochemical and mineralogical lines of evidence suggest that this volcanism was related to mantle plume activity.
The above-listed results partly prove thus positively support the "Plume Winter" scenario that the head investigator proposed more than 10 years ago. As the results contain several new finds and the first perspectives, we already reported in 29 articles in international scientific journals, 2 books, and 6 oral presentations at international meetings including 3 keynote speeches. Less
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