TYPES AND CHARACTERISTICS OF THE CATHAYSIAN BLOCK GROUP

The theory of block tectonics was put forward when the mapping project on "Tectonic Frame Map of China and Adjacent Regions" was lunched. With it the crustal evolution of China and adjacent regions is divides into 5 stages:the continental nucleus forming stage, the paleo-global tectonic stage which includes the platform forming stage and the stabilizing stage, the transitional stage and the neo-global tectonic stage. Blocks and junction belts are adopted and redefined as the second order tectonic units under the plate to reveal the tectonic evolution of the paleo-global tectonics stage, as the theory of plate tectonics has successfully illuminated the global tectonic evolution in the neo-global tectonic stage. By Late Permian, there were 3 block groups in China and adjacent regions as part of the Pangea:the Laurasia Block Group, the Cathaysian Block Group and the Gondwana Block Group. The Cathaysian Block Group is composed of a number of smaller blocks which have complicated evolutionary history and rich tectonic information respectively. In this paper, we collected and studied the data of regional tectonics, lithology and stratigraphy, plus detailed analysis of isotope dating data related to tectonic evolution stages, divided the Cathaysian Block Group into three types of North China, Yangtze and South China and stipulated their evolutionary history in detail. The platform forming stage of the North China type was completed in late PaleoProterozoic about 1.8Ga, the platform forming stage of the Yangtze type in early NeoProterozoic about 800 Ma, and the platform forming stage of the South China type by the end of Early Paleozoic 400Ma. Once the platforms were formed, they entered the stabilizing stage until the end of early Permian when they entered the transitional stage. Their evolution shows a similar sequence but different time schedule. After the Indosinian movement, as parts of the Eurasian Plate, the Cathaysian Blocks have moved into the neo-global tectonic stage.