The early rift sedimentation history of the South China Sea is still not well understood due to restricted borehole coverage of the Paleogene strata and lack of reliable stratigraphic dating. We use detrital zircon U‐Pb geochronology to explore the source‐to‐sink characteristics of syn‐rift sequences in the northern South China Sea. The results reveal significant intrabasinal provenances in addition to the well‐perceived terrigenous supply from the north. The Dongsha Uplift is considered to account for the dominance of the Early Cretaceous zircons in the Eocene samples. The Lower Oligocene sediments in the Qiongdongnan Basin could have been sourced from Hainan Island and local uplifts, but their distinction cannot be confirmed by the U‐Pb age spectra. Contemporary sediments in the northern Pearl River Mouth Basin were most likely transported from southeastern South China with well‐rounded zircon grains showing U‐Pb age similarity to those from the northeastern tributaries of the Pearl River. By contrast, intrabasinal sources from the west and east are suggested to have contributed the infill of the southern part of the Pearl River Mouth Basin based on generally euhedral zircon shapes. These sedimentary source patterns appear to change very little in the Oligocene northern South China Sea. However, the newly detected Neoproterozoic zircons in the Upper Oligocene sediments from borehole L21 tend to indicate a southern source. The episodic and diachronic nature of rifting and erosion processes in the early South China Sea is the cause of complex patterns in the Paleogene provenance history.

There are some active bottom currents on the northern continental slope of the South China Sea (SCS).Reflection seismic profiles show that the bottom current channels occur in the water depth range of 1000 to 2700 m, extending from the NE to the SW, leading to accumulation of discontinuous drifts with higher sedimentation rates on the eastern side of the channel. The stacking pattern of the layers suggests that these drifts propagated southwestward, following the direction of the bottom currents. One sedimentary drift to the southeast of the Dongsha Islands has the highest sedimentation rate of 97cm/ka in the last 12 ka. The sedimentary characteristics of the sediment layers indicate that these bottom currents are most likley caused by the water movement of a branch of the West Pacific Ocean Current, which enters the northern SCS via the Bashi Strait. Once formed, the bottom currents transport sediments along the northern slope of SCS southwestward and finally disappear into the central basin of the SCS. Due to the bottom current activity, the deep-sea sedimentary process in the northern SCS is complex. deep water bottom current, deep sea deposition, sedimentary drift, reflection seismic profile, South China SeaDeep water bottom currents could transport sediments over a long distance in the deep marine environment and form deposited drift with a high sedimentary rate [1] , which is apt to good reservoir for oil and gas hydrate. Due to the sedimentary exceptionalness and its economic value, bottom current deposition has been an important research field in marine sedimentation in recent years [1][2][3][4][5][6][7][8] . The core SO17940, 1315 cm long, was taken from a sedimentary drift in the northeastern slop of the South China Sea (SCS) during the SONNE cruise 95 in 1994 [9] . The sedimentation rate is about 33 cm/ka in the last 40000 years [10] , based on δ 18 O record and AMS 14 C dating. According to the record from ODP Leg 184 Site 1144 on this sedimentary drift in 1999 (water depth of 2037 m and the core is 51 900 cm long), the sedimentation rate reaches 49 cm/ka in the last 1.05 Ma [11] . The "Marion Dufresne" has taken a box-core, 1192 cm long, in this sedimentary drift (MD05-2905), the sedimentation rate is as high as 97 cm/ka in the last 12 ka, the highest record in the SCS. The sedimentary drift consists mostly of terrigenous material, with some organic carbon (about 10%-20%), and siliceous biota (<5%), and is completely homogenized by bioturbation. No slumping structure and mass transport have been found in the sediment core [11][12][13] , based on cores description of ODP1144 and MD05-2905. The formation and origin of the sedimentary drift is one of the key questions for the sedimentology in the SCS. The geological data and multi-channel reflection seismic profiles have been used to decipher these questions in this paper, the seismic profiles are about 3600 km long. The study

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Geochemical data from South China Sea sedimentary rocks show the effects of both source composition and depositional environments. This enables us to link tectonic trends with erosion in the Pearl River region since c. 32 Ma. In particular, a shift in the geochemistry appears to signal a response to a well-recorded regional tectonic event at c. 23-25 Ma, probably corresponding to a jump in the seafloor spreading axis from the west to the SW within the South China Sea. This may correlate with the uplift of the West Yunnan Plateau and possibly also the eastern Tibetan Plateau. Clay mineralogy, sand-mud ratio, and major and rare earth element concentrations, also varied in response to the environment in the drainage areas of the palaeo-Pearl River. By comparing data from the modern sources and the sedimentary record from the northern South China Sea, especially the erosion-transportation-deposition patterns, three groups of index minerals (Ati, GZi, ZTR), as well as rare earth elements can be recognized. These are used to characterize the Pearl River from the east to the west, representing three different parent rock sources. The evolution of the palaeo-Pearl River can be tracked by variations of heavy minerals and key elements that are indicative of provenance.