Palaeoplate pattern in China and its adjacent areas

Biogeographic and paleomagnetic data show that the early Paleozoic Cathaysian block group was closely related to Gondwana continent, and it began to split from Gondwana continent in the early and middle Devonian.

After Caledonian movement, Qaidam block, Qinling microplate and North China plate collided into a whole, and North Qinling and Qilian Ocean disappeared. From Devonian to Carboniferous, the South Qinling Ocean Basin was formed along Mianxian-Lueyang line. After Permian, the South Qinling Ocean gradually closed, and the Triassic collision formed the South Qinling orogenic belt.

Cathaysian plate group includes China-Korea plate, South China plate, Tarim plate and many other small blocks, such as Qaidam block, Qinling block, Songpan Ganzi block, Changdu-Simao block and Qiangtang block. Among them, the Yangtze plate collided with the Cathaysian plate in the late Early Paleozoic, forming a large-scale South China plate. Only the Qinfang Trough remained in the South China Sea until the end of the Early Permian. In the Late Paleozoic, the South China Plate underwent two remarkable rifting processes: Devonian-Early Carboniferous and Middle and Late Permian. It is characterized by the alternation of shallow carbonate platforms and deep-water basins in the South China plate. There are also signs (radiolarian siliceous rocks in northeastern Jiangxi) that the Yangtze plate and Cathaysian plate split again in the late Paleozoic, but whether the late Paleozoic ocean basin and two independent plates were formed is still controversial.

The Paleo-Asian Ocean between Tarim Plate, North China Plate and Siberia and Kazakhstan Plate gradually closed and disappeared in the Late Paleozoic. During the late Devonian to the late Carboniferous, the Tarim plate quickly moved northward to about 30 north latitude, and its northern edge gradually collided with the Kazakhstan plate, thus causing the molecules of Angara flora to invade this area in the late Permian. In the late Permian, the North China plate gradually merged with the Siberian plate, and the ancient Asian ocean finally disappeared.

Songpan Ganzi block on the northwest edge of South China plate is a part of Yangtze plate. The late Paleozoic strata in this area are mainly carbonate rocks, which are similar to the Yangtze plate in biota and lithofacies. The Simao-Lanping-Changdu-Qiangtang area may be a strip composed of micro-blocks in the late Paleozoic. They separated from the South China Plate in Devonian, forming the initial Jinshajiang-Ailaoshan ocean basin, and formed an open ocean basin in Late Carboniferous-Early Permian.

In the Late Paleozoic, Bangongcuo-Lancangjiang Ocean was the main ocean basin separating Cathaysian block group and Gondwana block group. Gondwana mainland in China mainly includes Lhasa mainland, Gangdise mainland and Baoshan mainland. They are very similar to Gondwana in sedimentary characteristics and biogeography.