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Yongjie Tan, Development and Research Center, China Geological Survey (China)
Ruizhao Qiu, Development and Research Center, China Geological Survey (China)
Su Zhou, China University of Geosciences (China)
Tingdong Li, Chinese Academy of Geological Sciences (China)
Jinfu Deng, China University of Geosciences (China)
Qinghui Xiao, Information Center of Ministry of Land and Resources (China)
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The lithosphere thinning and Mesozoic metallogenic explosion in east China was one of the most noticeable scientific issues in the recent decade. Regarding to its dynamic bacground, various view points have been proposed by the geologists both at home and abroad, and have become a hot spot to be widely concerned. Based on the studying on the ages of igneous rocks and deposits in east China, a new viewpoint on the genesis of the granites and geodynamic setting in east China was proposed.
The geological-setting of the granites and associated deposits in east China is belong to the active continental margin of east Asia in Mesozoic, their formation and evolution is generally regarded as associated with the Pacific crust subduction towards to the below of the Asia continent, but generally the width of magmatic belt associated with the subduction is less than 100 kilometers, so it is hard to explain why the magmatic belt in east China extend to inland more than 1000 kilometers. According to the history of the formation of China continent, after Triassic the China continental blocks had been pieced together to form an entity; the most important Mesozoic geological event of China continent was the Tethyan Ocean developed in the west and orogenic belt in the east. In the deep process in the J-K period, the development and evolution of Tethyan oceans in west China was a token of hot mantle-flow upwards with the process of extension with lithosphere thinning as a whole, with the unstable orogenic lithosphere-root lost, more material and heat of convective mantle was urged to input into the continental crust along the lithospheric discontinuities, more asthenospheric material upwelling may cause the magmatism to come to a climax in J3 and K1 and led to large-scale mineralization happened about 120 Ma to 140Ma. it comes to us that the Pacific crust subduction was not the only factors, and the Genesis and Geodynamic Setting of the Granites and Mineralization in Mesozoic, east China probably was the combined result of the systematic changing of lithosphere/asthenosphere in China continent and the subduction of the Pacific plate.
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