：层序地层学前期研究注重顺物源方向的二维剖面解释，垂直物源方向的层序结构差异性 是当前研究的热点和难点。以南海琼东南盆地西区晚更新世（0.125 Ma 迄今）陆架边缘地层序列 为例，通过典型地层终止关系、地层叠置样式和陆架边缘迁移轨迹方法，识别了体系域单元内部结 构和组合特征，自下而上划分为低位体系域（LST）、海侵体系域（TST）、高位体系域（HST）和下降 体系域（FSST）。其中下降体系域内部分界面（WSTS）可将下降体系域分为早晚两期，该界面对应 陆架边缘迁移轨迹角由正到负和地层叠置样式由进积到降积的转换面。琼东南盆地西区上更新 统发育稳定型和滑塌型两类陆架边缘层序结构，随着相对海平面的变化，稳定型陆架边缘主要发 育多期次陆架边缘三角洲和深水扇沉积，滑塌型陆架边缘则主要发育大规模峡谷和块体搬运沉积 体系；响应于“快速海侵而缓慢下降”的不对称海平面升降特征，晚更新世陆架边缘层序表现为较 薄或者不发育的低位—海侵体系域，厚的强制海退楔单元，而外陆架区活动性断裂增加了高位体 系域组分在层序中的占比。先存的坡折地貌、断裂活动及非对称海平面升降旋回差异共同导致了 研究区层序结构多样性体系，高频层序地层驱动机制的定量化探索是更新世层序地层学未来发展 趋势，该研究为层序地层学标准化实践和侧向层序结构差异研究提供了一定的参考意义。

Previous sequence stratigraphy research mainly focuses on the two-dimensional seismic interpretation in its dipping direction, while the variations of sequence architectures in vertical provenance direction is the focus and difficulty of current research. This study takes the Late Pleistocene (0.125 Ma to today) shelf margin stratigraphic successions of the Qiongdongdong Basin as an typical example. The internal structure and combination characteristics of the systems tract units are established and identified, according the methods of typical stratal terminations, stratal stacking patterns, and shelf-edge migration trajectory. The systems tract in the studied sequence are classified from bottom to top, including the lowstand systems tract (LST), the transgressive systems tract (TST), the highstand systems tract (HST), and the falling stage systems tract (FSST). Among them, the part of the interface within the falling stage systems tract (WSTS) divides the FSST into early and late phases. The WSTS interface is the transitional surface for the positive to negative angle of the migration trajectory of the shelf-edge and for the stratal stacking transition from progradation to degradation. The stabilized and collapsed types of shelf-edge sequence architectures have developed in the Upper Pleistocene of the western part of the eastern Qiongdongnan Basin. With the change of relative sea-level, the stabilized shelf-edge mainly develops multi-phase shelf margin deltaic and deep-water fan deposits, while the collapsed shelf-edge mainly develops large-scale canyons and mass transport deposits. In response to the a short sea-level rising but a prominent falling cycle, the late Pleistocene shelf-edge sequences are composed of thin or undeveloped LST and TST units, and a thick FSST unit, whereas the active faults in the outer shelf locations increase the proportion of the HST unit in sequences. The pre-existing slope break geomorphology, fault activities and asymmetric sea-level fluctuation coevally lead to a diverse of the sequence architectures in the study area. The quantitative exploration of highfrequency sequence stratigraphic driving mechanisms is the future development trend of the Pleistocene stratigraphy, and this study provides a potential reference significance for the standardization of 3D sequence stratigraphic investigations.