Characteristics and evolution of Cenozoic sediments in the Liyue Basin, SE South China Sea

The Liyue Basin in southeastern South China Sea is considered to be a Cenozoic basin superimposed on the Mesozoic Erathem. The present account is based on comprehensive analysis of seismic profiles, dragnet and core samples. Cenozoic deposits in the basin are characterized by a sequence of marine detrital and carbonate rocks. There are two regional unconformities (T70 and T40), corresponding to the commencement and termination of sea-floor spreading in the South China Sea, in the Late Oligocene and late Early Miocene respectively. The Cenozoic sedimentary evolution of the basin recorded different sedimentary responses to sea-floor spreading in the South China Sea, and reflected differences in the basin structure, paleogeographic pattern and sedimentary characteristics before 30 Ma (Late Oligocene) and after 30 Ma. The evolution of sea-floor spreading, changes in sea level and sediment sources controlled the Cenozoic sedimentary infill.

► Identified 9 seismic sequence boundaries on 2D seismic profiles in the Liyue Basin. ► Seized the geologic property and tectonic implication of the main unconformities in the Liyue Basin. ► Divided the Cenozoic sedimentary evolutionary history of the Liyue Basin into two stages.