In this paper the author first reviews 6 major advances in the study of Precambrian geologyand tectonics of South China during the last decade, and then proposes the following new modelof Late Precambrian scissors-typ...In this paper the author first reviews 6 major advances in the study of Precambrian geologyand tectonics of South China during the last decade, and then proposes the following new modelof Late Precambrian scissors-type opening-closing tectonic evolution in the region. (1) Besidesthe Middle-Late Proterozoic low-grade metamorphic basement, there existed a LateArchaean-Early Proterozoic medium- to high-garde metamorphic basement in South China;both of them formed the united Yangtze-Cathaysia (craton) at the end of the Early Proterozoic,with the Jiangxi-Anhui-Zhejiang palaeogulf extending into the inland and the Jiangxi-Anhui-Jiangsu Peninsula lying on the northern side of the palaeogulf.(2) From the Middle Proterozoic,the present Guangxi-Guizhou-Hunan area in the western-central oldland was subjected toextensional rifting and became a rift trough, thus resulting in counterclockwise rotation of the"Cathaysian block" and clockwise rotation of the "Yangtze block"; moreover, the southwardcompression of the Dabie-Jiaonan block which split from the southern margin of the NorthChina plate and was accreted to the northern margin of the Jiangxi-Anhui-Jiangsu Peninsula ledto the scissors-type closing of the Jiangxi-Anhui-Zhejiang palaeogulf during the Middle-earlyLate Proterozoic, which further influenced the Early Palaeozoic tectonic evolution of the region.展开更多
文摘In this paper the author first reviews 6 major advances in the study of Precambrian geologyand tectonics of South China during the last decade, and then proposes the following new modelof Late Precambrian scissors-type opening-closing tectonic evolution in the region. (1) Besidesthe Middle-Late Proterozoic low-grade metamorphic basement, there existed a LateArchaean-Early Proterozoic medium- to high-garde metamorphic basement in South China;both of them formed the united Yangtze-Cathaysia (craton) at the end of the Early Proterozoic,with the Jiangxi-Anhui-Zhejiang palaeogulf extending into the inland and the Jiangxi-Anhui-Jiangsu Peninsula lying on the northern side of the palaeogulf.(2) From the Middle Proterozoic,the present Guangxi-Guizhou-Hunan area in the western-central oldland was subjected toextensional rifting and became a rift trough, thus resulting in counterclockwise rotation of the"Cathaysian block" and clockwise rotation of the "Yangtze block"; moreover, the southwardcompression of the Dabie-Jiaonan block which split from the southern margin of the NorthChina plate and was accreted to the northern margin of the Jiangxi-Anhui-Jiangsu Peninsula ledto the scissors-type closing of the Jiangxi-Anhui-Zhejiang palaeogulf during the Middle-earlyLate Proterozoic, which further influenced the Early Palaeozoic tectonic evolution of the region.
