POSITION OF SOUTH CHINA IN GONDWANA

It is generally accepted that South China was located along the northern periphery of East Gondwana. However, its precise position relative to India and Australia is debated. In all the previous models, the Yangtze and Cathaysia blocks, the two major components of South China, were amalgamated by the Tonian, and South China was considered as a single coherent block in Gondwana. Based on a summary and critical re-evaluation of available palaeomagnetic, paleontological, stratigraphic and detrital zircon data, we propose that Yangtze and Cathaysia were not juxtaposed until the early Paleozoic and had been located at two separate parts of the northern margin of Gondwana before then. Yangtze was located to the northwest of India in the Ediacaran and early Cambrian. Cathaysia was close to or a part of northern Australia in the Ediacaran, when Australia and India were separated by the Kuunga Ocean, and amalgamated with the eastern margin of India in the late Ediacaran to early Cambrian when the ocean closed. Our model implies that the Early Paleozoic orogeny in South China could be related to two distinct events, the late Ediacaran to early Cambrian collision of Cathaysia/Australia with India (the Kuunga orogeny) and the late Ordovician amalgamation of Cathaysia with Yangtze. It also implies that Yangtze and Cathaysia likely occupied two separate positions in Rodinia.