Evolution of the South China paleocontinent and related resource-environment developments: From Columbia to Gondwana

Key words: 
• Colombia Supercontinent /
• Rodinia Supercontinent /
• Gondwana Continent /
• Yangtze Block /
• Cathyasia Block /
• Proterozoic to early Paleozoic

Abstract: Amalgamation and fragmentation cycles of the global Supercontinents from the Proterozoic to early Paleozoic profoundly related to the geological evolution and distribution of massive economic resources in South China Block. Here we focus on the tectonic framework of the South China Block and related processes of geodynamic evolution and their impact on resources formation and environmental development in the context of assembly and breakup of the global supercontinents. The Yangtze Block of South China experienced similar tectonic events to the Laurentia at early Paleoproterozoic, implying their close affinity before the Columbia (Nuna) assembly. Although the impact of tectonic evolution exists in different parts, the Yangtze Block recoded the assembly and breakup of the Columbia supercontinent, while the Cathyasia Block only shows the records of subduction-collision related to the supercontinental assembly. Before ca.820 Ma, a regional unconformity was developed along the southeastern margin of the Yangtze Block and the onset of sedimentary overlap represented a new cycle of basin evolution since the breakup of the Rodinia supercontinent. Subsequently, the South China Block experienced five evolutionary periods, represented from old to young by (a) the embryonic to young rift (820-800 Ma), (b) the mature rift (800-720 Ma), (c) Early glacial (720-660 Ma), (d) Interglacial (660-650 Ma), and (e) Late glacial periods (650-635 Ma). The South China Block experienced early Paleozoic orogen that was closely associated with the Gondwana assembly and was close to Australia or India. Critical geological events in South China such as Neoproterozoic Snowball Earth is considered to be tightly linked to the Rodinia breakup, while Precambrian giant economic deposits of Fe, Mn, and P were largely controlled by the magmatic-sedimentary events. Furthermore, successive uplifting-subsidence processes promoted the formation and evolution of Paleozoic sedimentary basins with high-quality source rocks, large-scale reservoirs and seals, which are critical for the development of hydrocarbon resources.