Sediment And Range Of The Submarine Delta Of The Abandoned Yellow River In Northern Jiangsu Province

According to the seismic profiles related to the Abandoned Yellow River Delta, and cores drilled by other researchers, this paper analysizes the range and structure of the submarine delta of the Abandoned Yellow River. At the same time, this dissertation also applies ArcGIS to synthesize the sediment of the the Abandoned Yellow River Delta, the study shows:First, interpretation on the profiles getting from geophysical survey in the western of south Yellow Sea shows that there are four distinct reflecting interfaces named T0, T1, T2, T3, which include one seabed surface (TO), one conformable surface (T1) and two unconformable surfaces (T2, T3); at the same time, there are four stratum units with different sediment thickness, which named U1, U2, U3, U4.U1is located in the interface of TO and T1with moderate to fine continuity, parallel to subparallel reflection configuration, moderate amplitude, it has concordant contact with sea bed, concordant and onlap contact with T1, part of this unit doesn’t have reflection.U2is located in the interface of T1and T2with moderate continuity, parallel to subparallel reflection configuration, moderate amplitude, it has concordant and toplap contact with T1, concordant and onlap contact with T2.U3is located in the interface of T2and T3with moderate to bad continuity, moderate to high amplitude, undulant and chaotic reflection configuration, part of this unit doesn’t have reflection. It has erosional and toplap contact with T2, downlap contact with T3.U4is located below the interface of T3with bad continuity, moderate to high amplitude, undulant and chaotic and reflection configuration, partially with parallel and subparallel reflection configuration. It has erosional contact with T3. Although thickness of sediment among four units, it decreases from land to sea.Second, according to the analysis of the inner reflecting structure, the outer geometrical morphology, the amplitude and continuity of seismic face, the paper successfully distinguishes a lot of geomorphologic types.There is one paleodelta in the BH6profile with oblique progradation bedding has downlap contact with the bottom; meanwhile, there is also one obvious delta front subfacies deposition in the northern of BH1profile with oblique progradation bedding, moderate continuity, moderate to high amplitude and moderate to fine continuity separately has toplap and downlap contact with sea bed and the bottom.There is one large basin-fill in the northern BH1profile with parallel and subparallel reflection configuration has onlap contact with the bottom.At the same time, there is a combined fill in the slope of the northern of BH1with oblique and chaotic reflection configuration has downlap contact with the bottom, and onlap contact with the top, where its configuration is parallel and subparallel.Third, Compared with the core named QC4, analyzing the sediment of Ul, this article finds out that sediment in the cape of Abandoned Yellow River Delta is declining, while sediment is increasing from the cape of Abandoned Yellow River Delta to its northern side and southern side and forms two sedimentation center. This phenomenon may be related to the sediment which is eroded from the cape and then transported to sides. Moreover, there is a piece of thin sediment formed off the coast of the cape of Abandoned Yellow River Delta, which runs northern to southern, almost parallel to the coast, just likes a trough comparing with the surrounding topography. This phenomenon fits the fact that residual current runs northern and southern and wave power converge wave refraction and in the cape of the Abandoned Yellow River Delta.Fouth, based on the data of sedimentology, micropaleontology, chronology and shallow seismic profiles, this paper synthetically analyzes and draws a conclusion that the submarine Abandoned Yellow River Delta exists in the south of DongXi Island located in the top of the HaiZhou Bay and station of8426, whose latitude is34°38.30’N, and station of SYS-0701, whose latitude is34°39.7535’N, east to the western side of longitude of122°E, goes through the southern of survey line of D-D’, and south to the QiangGang, the depth of water in the margin of the submarine is around20meter.Fifth, according to the income and expenses of the sediment in the Abandoned Yellow River Delta, applying the module of spatial analyst in the ArcGIS, the article calculates the sedimentation and concludes that the volume of the sediment of the Abandoned Yellow River Delta calculated by304years is4332×108t～4547×108t, while the same firsthand data calculated by360years is4413×108t～4679×108t; the amount of the sediment discharged by the Yellow River is14.3×108t～15.0×108t per year if the river spends304years to construct the Abandoned Yellow River Delta; however, supposing it takes the river360years to give birth to the giant delta, the amount of the sediment loaded by the Yellow River is12.3×108t～12.9×108t per year. From the outcome, this article shows that all results are comparatively consistent with the conclusion drawn by other academics. In a word, the amount of the sediment delivered handled by this article is reasonable and the range of the Abandoned Yellow River Delta is reliable.