南海北部深水区古近系沉积物源演变及古地理意义OA北大核心CSTPCD

The deep-water area of the northern South China Sea experienced a transition from lacus-trine to marine environments in the Paleogene,and has rich oil and gas resources and broad exploration prospects.Due to the limitation of water depth,the provenance of sediments and the palaeogeographic evo-lution of the basin are not clear.In this paper,the Paleogene of the Zhu-2 depression in the Pearl River Mouth Basin is systematically studied by means of detrital zircon U-Pb ages and source-sink correlation.The results show that in the Early and Middle Eocene,the sediments of the Zhu-2 depression were mainly from local uplift area around the depression.In the Late Eocene,the Kunyingqiong River originated from the western side of the depression provided a large amount of sediments for the basin,whereas the Paleo-Pearl River sediments had little influence on the deposition in the depression.In the Oligocene,the Paleo-Pearl River crossed the Panyu low uplift and entered the Baiyun sag,carrying sediments mixed with the Kunyingqiong River sediments in the form of delta deposition in the north and mid-west of the sag,forming a dual provenance river-delta system.The Paleogene provenance evolution of the deep-water area of the northern South China Sea was obviously controlled by regional tectonic palaeogeography of the Mesozoic.Identifying the provenance evolution during this period is of great significance for restoring the regional palaeogeography pattern.