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以过南海北部陆缘的珠江口盆地白云凹陷中部的第一条长电缆深反射地震剖面(14s)作为研究的基础,对该剖面进行了速度分析、时深转换及精细地震解释,探讨了白云凹陷的深部构造特征.该剖面深部反射特征非常清晰,莫霍面表现为一个起伏不平、厚薄不一的“层”,其厚度可达1~3km.地壳厚度从陆架、陆坡向海盆明显阶梯式减薄,在白云主凹的沉积中心处仅厚7km左右.在剖面的最东南端下陆坡部位,深部(10~21km)有三个略显起伏、彼此大致平行的强反射条带,推测为莫霍面之下存在俯冲洋壳的显示.在白云凹陷可能存在深大断裂,凹陷的持续强烈沉降可能与深大断裂的长期活动有关.
Based on the first long cable deep reflection seismic profile (14s) in the central part of Baiyun Sag in the Pearl River Mouth Basin in the northern margin of the South China Sea, the paper analyzes the velocity, time conversion and fine seismic interpretation of the profile, The deep reflection feature of this section is very clear, and the Moho surface is characterized by an undulating layer with a thickness of 1 ~ 3 km. The thickness of the crust is obviously stepped from the shelf and the slope to the basin Thinning only about 7km thick in the sedimentary center of the main depression of the Baiyun Formation.At the lower part of the slope (10 ~ 21km) in the southeastern part of the profile, there are three strong reflection bands roughly parallel to each other, presumed to be Mo There are subduction oceanic crust beneath the Huo-nian surface, where there may be deep-seated faults and sustained strong settlement of the sag may be related to the long-term activities of the deep faults.