Fan-Delta and Related Turbiditic Deposits on the Steep Slope of Dongying Depression, Bohai Bay Basin
The fan-delta in the fourth member of Shahejie Formation in steep slope of Dongying depression belongs to prograded type. The proximal part of the deposit is dominated by the successive deposition of sandstone aprons with a few channel plug sandbodies produced through rapid sedimentation from channelized sediment-laden debris flows. The middle part, on the other hand, is mainly represented by the stacked channel-fills with alternate sandstone aprons. Following the deposition of bedded sandstones, as the slope of the depositional surface reduced, debris flows with relatively less grain concentration extended towards the ambient waterbody through channels incised into the preexisting unconsolidated sediments. The thick stacks of channel-fill sandbodies were developed as a consequence of vertical channel aggradation under continued hangjngwall subsidence, and the upward declining trend in vertical aggradation suggests gradual fall in the rate of this subsidence. Distal fan-delta deposits represents beds characterized by a repetition of sandstone and mudstone layers. Each stratum is thin-to medium-bedded and forms a succession with a thickness range of decimetres to several metres. The present study indicates that gravity channel and slumps formed in the prodelta region of the fan delta.
Dongying depression fan-delta gravity channel slump depositional model.
Zhang Jinliang Zhang Xin
College of Marine Geosciences, Ocean University of China, Qingdao 266100, China
国际会议
The IPACES 6th Annual Meeting(“现代地球科学，交流与合作国际学术研讨会暨第六届IPACES学术年会)
武汉
英文
314-316
2007-04-25（万方平台首次上网日期，不代表论文的发表时间）