【摘要】 利用传统的地震相分析方法,分析总结现代长江水下三角洲浅地层地震剖面反射波的几何形态、内部反射结构、连续性、振幅等特征,形成对长江水下三角洲各典型地震相特征的认识,圈定相应的地震相范围,并结合钻孔资料,解释了长江口范围三角洲前积、浅海沉积、古河道等各沉积相的分布。结果表明,现代长江水下三角洲浅地层各地震相特征明显。典型的三角洲前积地震相主要分布在长江口外东北部,其余大部为典型浅海沉积地震相,且浅海地震相特征向口内逐渐变弱,表现为浅砂或淤泥型地震相,向口外逐渐有晚更新世基底地震相出露,并发育古河道地震相,此外,浅层气地震相嵌入区内各个地震相范围。更多还原

【Abstract】 According to the traditional method for seismic facies analysis,geometrical shapes,internal reflection structures,facies boundaries,continuity and amplitude of the shallow strata of the Yangtze River are studied by this paper,upon which seismic facies recognized.Incorporated with borehole data we established the facies framework which includes deltaic deposit,shallow sea deposit and paleo channels of the river.Typical seismic facies of delta front are mainly distributed in the northeastern part of the Yangtze River mouth,and the rest of the area is dominated by shallow marine facies.Shallow marine facies consisting of sand and silt are gradually thinning out towards the mouth.Instead,late Pleistocene basement seismic facies gradually crop out at the mouth,decorated by paleochannel seismic facies.Shallow gas seismic facies always invade into other seismic facies.更多还原