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ASI-01 Geodynamic evolution of Asia - Part 2
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Relationship of the large-scale mineralization happened with the dynamic evolution process of Lithosphere in China continent
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Ruizhao Qiu, Development and Research Center,China Geological Survey (China)
Jinfu Deng, China University of Geosciences (China)
Su Zhou, China University of Geosciences (China)
Tingdong Li, Chinese Academy of Geological Sciences (China)
Xiufa Chen, Development and Research Center,China Geological Survey (China)
Chunhua Yuan, Development and Research Center,China Geological Survey (China)
Jiuxi Han, Development and Research Center,China Geological Survey (China)
Liangliang Wang, Development and Research Center,China Geological Survey (China)
Zhen Chen, Development and Research Center,China Geological Survey (China)
Yuming Chen, Development and Research Center,China Geological Survey (China)
Dawen Liu, Development and Research Center,China Geological Survey (China)
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The large-scale mineralization in China continent could be divided into three periods and areas, late Paleozoic in north China associated with the Paleo-Asia ocean closed, Mesozoic associated with the orogenic belt in the east China, and Cenozoic in southwest China associated with event of the Tethyan Ocean represented by Yarlung Zangpo closed. They happened have the closest relationship with the dynamic evolution process of lithosphere in China continent.
China continent was consisted of the five types lithospheres, namely, the cratonic, the orogenic, the rift, oceanic crust and island-arc. Different type lithospheres with the different dynamic mechanism and effect, The area between the different type lithospheres must be the lithospheric discontinuity zones, and should be have the close relationship with the metallogenesis. Facts, absolute majority of known metal deposits in China continent distribute in the lithospheric discontinuity or activating discontinuity, indicate the lithospheric discontinuity providing the favored move-store space for large-scale deposits. China continent was pieced together by the orogenic belts in different periods, and the orogenic belt was the unstable lithospheric unit, also called the lithospheric discontinuities, which show differences on the crust-mantle structure, rock composition, heat flow and thickness of the continental crust and lithosphere with the conterminous lithospheric units. On the basis of this concept, combined with the fact that most metallic ore deposits in continental China are distributed in lithospheric discontinuities, it is indicated that the lithospheric discontinuities and reactivated discontinuities provide a framework of source-migration-accumulation for the formation of huge ore clusters and are favorable ore-housing spaces for the formation of large ore deposits.
According to the metallogenic characteristics, peak period of magmatic activity and main metallogenic epochs in the northwest, east and southwest of China, combined with the ages of formation of lithospheric material and structure, it is proposed that the main period when the strongest and last magmatism occurs in an area is also the main period for the formation of lithospheric material and structure. This reflects the constraints of the lithospheric evolution on large-scale metallogenesis. In other words, large-scale metallogenesis in an area is initiated in a period of instability and de-rooting of the orogenic lithosphere and large-scale upwelling of the asthenosphere. The occurrence of C-type adakite is one of such indicators.
Acknowledgements: This research is funded by the Projects of China Geology Survey (1212010561502, 1212010561501), the support projects of the science and technology(2006BAB01A03), key project of the international cooperation on the science and technology(2007DFA21380), Ministry of Science and Technology in China and the National Fund of Nature Science of China (40572063).
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