Full length articleSource and sink characteristics of the continental slope-parallel Central Canyon in the Qiongdongnan Basin on the northern margin of the South China Sea

- The supplying and unloading of the sediments in the Central Canyon were studied.
- The provenance of the Ledong submarine fan and Central Canyon was Eastern Vietnam.
- Sediments of the Shuangfeng submarine fan were transported by the Central Canyon.
- The growth of the Central Canyon has a good implication for tectonic activity of the Vietnam and Red River Fault.

The “source-conduit-sink” model is crucial for studying deep-water sedimentary systems along a continental margin. Using seismic data, bulk rare earth element compositions of sediments and zircon U-Pb age data, we examined the supply and deposition (i.e., the source and sink) of the sediments in the Central Canyon of the South China Sea. Five phases of secondary canyon fill are present in the Central Canyon. The natural levees developed at the head of phase 1 of the secondary canyon deposits indicate that the Central Canyon initially developed at 10.5 Ma. The sediments in the Central Canyon were supplied by the Ledong submarine fan, and the provenance of the material in the Ledong submarine fan and Central Canyon was eastern Vietnam. Large amounts of sediments were transported through the Central Canyon to the Shuangfeng Basin and deposited during four phases of submarine fan development. Phases 1-3 of the Shuangfeng submarine fans are composed of deep-water branching channel and inter-channel sediments. Phase 4 of the Shuangfeng submarine fan consists of deep-water channel and lobe sediments. Tectonic events, including the broad uplift of the Tibetan Plateau and central-southern Vietnam during the late Miocene, reversal of the strike-slip Red River Fault, and rapid subsidence in the Qiongdongnan Basin at approximately 5.5 Ma, provided favourable conditions for the growth of the Ledong submarine fan, Central Canyon and Shuangfeng submarine fan system.

311