134 / 2022-02-25 23:19:44

Sedimentary distribution characteristics and sedimentary model of Zhuhai Formation, Central of Zhu-3 Depression

Pearl River Mouth Basin，Zhu-3 Depression，Upper Oligocene，Provenance，Sedimentary type

In order to solve the problems of insufficient research on the sedimentary distribution of Zhuhai Formation of Upper Oligocene in the middle of Zhu-3 Depression, complex provenance and differences in sedimentary facies types, this paper uses core, drilling and logging, seismic data, as well as analysis and test data such as particle size, heavy minerals and thin sections, and comprehensively considers various factors such as structural evolution, provenance system and core characteristics, The sedimentary facies analysis and vertical evolution law of Zhuhai Formation in the middle of Zhu-3 Depression in Pearl River Mouth Basin are studied. The Zhuhai Formation in the study area mainly develops three sedimentary facies types: tidal flat, braided river delta facies and fan delta facies. Both braided river delta facies and fan delta facies develop delta plain and delta front subfacies. The provenance supply mainly comes from two provenance systems: Yangchun uplift in the northwest and Shenhu uplift in the southeast. In addition, the axial Braided River Delta extending from the Northeast indicates that there is also an extrabasin source in the northeast. During the sedimentary period of Zhuhai Formation in the study area, the seawater intruded from south to north, the Yangjiang low uplift gradually contracted into an isolated structural high point in the coastal environment, the tidal flat facies was widely developed, the braided river delta was well developed, the Shenhu uplift gradually submerged in the water, and the fan delta changed from large to small and disappeared at last.