Analysis Of Sedimentary Characteristics In The Guangli River Estuary And The Western Laizhou Bay

Based on the actual measured data of 45 surface samples and 16 core samples,the sedimentary environment of the northern tidal flat of the Guangli Estuary and the western part of Laizhou Bay was analyzed.Through the grain size and geochemical data,combines the research results of river age characteristics,deposition rate and shoreline changes,this paper analyzes the modern sedimentary environment of the northern tidal flat of Guangli River estuary and the evolution of sedimentary environment in the western part of Laizhou Bay in the past 100 years,and has obtained certain research results.The northern tidal flat of Guangli Estuary is located at the junction of the modern Yellow River Delta and the Weihe-Mihe Delta.The Yellow River formed a major sedimentary framework for sediments entering the sea during the period from 1929 to 1934,but the modern sedimentary environment was more affected by the Guangli River system.The western part of Laizhou Bay can be divided into five sedimentary units,according to the degree of influence of the Yellow River,including grain size,provenance,underwater topography and other information.The southern marginal zone of the modern Yellow River estuary is the side edge of the modern Yellow River underwater delta.According to the deposition rate,it can effectively reflect the age characteristics of the Yellow River into the sea.The abandoned Yellow River underwater delta was formed during 1929 to 1934.Due to the difference in external dynamics,the abandoned underwater delta can be divided into two parts: the northern tidal flat of the Guangli River estuary and the Central shallow sea.The sediments of the northern tidal flat of the Guangli Estuary from 1934 to the present are discontinuous in the age.It can be preliminarily judged that 80 cm below the surface layer was formed in 1934.The reconstruction of sediments by the Guangli River has not changed the overall sedimentary pattern.Seawater dynamics and coastal rivers affect the sedimentary environment in the Central shallow sea,and the provenance is complex.The Xiaoqing River estuary and its adjacent area are a transitional zone.Although the Yellow River affects the sedimentary environment,it is no longer the dominant factor.The sedimentary environment on the southern bank of Laizhou Bay is not affected by the Yellow River.Since 1855,the shoreline has been basically stable and the deposition thickness is thin.