1999 Fiscal Year Final Research Report Summary
Reconstruction of Early Paleozoic arc-trench system: a case study in the eastern Gondwana margin
| Project/Area Number |
10041102
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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 |
Geology
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
WATANABE Teruo Grad. School of Sci., Hokkaido Univ., Pro., 大学院・理学研究科, 教授 (40135900)
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| Co-Investigator(Kenkyū-buntansha) |
TSUNOGAI Toshiaki Fac. Of Education, Shimane Univ., Lecturer, 教育学部, 講師 (50252888)
SANO Sakae Fac. Of Education, Ehime Univ., Associate Professor, 教育学部, 助教授 (10226037)
HYODO Hironobu Senior Reseach Institute of natural Sci., Okayama Univ. of Sci., Lecture, 自然科学研究所, 講師 (50218749)
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| Project Period (FY) |
1998 – 1999
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| Keywords | Gondwana / Rodinia / eclogite / Serpentinite melange / Australia / arc-trench system |
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| Research Abstract |
The target of our research is to reconstruct the Early Paleozoic arc-trench system along the eastern margin of Gondwanaland. However, the chronological results on Attunga eclogite and host gabbro in the serpentinite melange yield a range from 660Ma to 460Ma zircon U-Pb SHRIMP gaes with 660Ma, thus the time span for rearch has been expanded to Neoproterozoic. Tectonics of Neoproterozoic along the later Gondwana eastern margin include those of breakup process of the Rodinia supercontinient . We obtain the following results
1) We propose a model of the Phillipne type for Early Paleozoic Gondwana margin.
2) In Latest Neoproterozoic, a subduction zone was produced. Simultneously, a rifting and opening of an ocean in the Kanmantoo Fold Belt occurred in the Eastern Gondwana part.
3) Serpentinite melange includes various kinds or igneous and metamorphic rocks. Their ages range from Neoproterozoic to Early Mesozoic.
4) During the Rodinia breakup, petrochemical evidence of mantle plume activity is obatained.
After the breakup, arc systems were formed firstly in SW Siberia and then Australia.
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