【摘要】 线状陆架沙脊一直是海洋地质学和沉积学研究的热点。基于东海近海底1700km2的三维地震数据,对陆架沙脊开展地震地貌学、沉积构型、成因和演化研究,并取得以下3点认识:(1)研究区发育7条NW-SE向陆架沙脊体系,海底呈槽脊相间地形特征。沙脊表面发育NE-SW向沙波体系。脊1、脊2、脊4和脊6表现为2～3条交叉或合并的沙脊体系,而脊3、脊5和脊7呈现为独立沙脊体系。(2)线状陆架沙脊横剖面左右不对称,宽2～11km,脊高3～31m,坡面相对较缓,倾角大多小于1°。(3)研究区水深变化和近海底潮流速度等因素指示研究区沙脊处于活动沙脊和衰亡沙脊的过渡阶段。研究第四纪陆架沙脊对沙脊储层的预测具有一定的指导意义。更多还原

【Abstract】 The study on linear shelf sand ridges is always a hot topic in the field of marine geology and sedimentology. On the base of near-seafloor 3D seismic data which covers an area of 1 700 km2 ,the seismic geomorphology,sedimentary architecture,genesis and evolution of the shelf sand ridges were discussed in this paper. The following conclusions have been drawn from this study: (1) 7 NW-SE oriented shelf sand ridge systems have developed in this study area. The seafloor in the study area is characterized by a ridge-and-swale topography. Sand waves oriented NE-SW have been observed in the surface of the sand ridges. The ridge 1,ridge 2, ridge 4 and ridge 6 were composed of 2 to 3 cross-combining sand ridges. While the ridge 3,ridge 5 and ridge 7 were revealed as a single sand ridge in the study area. (2)The linear sand shelf ridges are asymmetric in cross section and are oriented parallel to the current direction. The sand ridges have a length between 2 km and 11km. Their heights are from 3 m to 31 m. The angle of dip of the slope is mostly less than 1°. (3) In this study area,the stage of the sand ridges between active sand ridge and moribund sand ridge have been indicated by the change of water depth and the velocity of tidal current. Investigation of sand ridges on the Quaternary shelf is of critical importance for predicting tidal sand reservoirs.更多还原