Shallow Braided Deltaic System in Enping Formation of Huizhou Depression,pearl River Mouth

Shallow lacustrine deposits are widely distributed in the Enping Formation of the Huizhou depression of the Pearl River Mouth Basin,and has long been considered as a kind of infilling of a faulted basin.Through the study of lithology,geophysical responses,paleontology,geochemical proxies,and grain size distribution,this paper confirms that a special delta,shallow braided river delta,was developed in the Enping Formation of the Huizhou depression in a broad shallow flat lake,with sufficient terrigenous deposits.And this system is characterized by a well-developed delta plain,an undeveloped coarsening-upwards sequence of a mouth bar,and a well-developed braided stream.Depositional features of shallow braided delta are widely observed,such as the lacustrine deposits formed in the fault-sag transition stage,wide-spread thin coal seam,high sedimentation rate,widely distributed sand body,and coarse deposits in the research area,totally different with the depositional features of the infilling deposits in a faulted lake.The new model may help exploration in the Eogene of the Huizhou depression.