This study establishes a Holocene sedimentation model for the incised valley of the Yangtze Delta based on key information taken from existing literature and new cores collected for this study. Distinctive sedimentary processes and mechanisms operating in the incised valley were revealed: 1) the significant role of a pre-Holocene incised valley on which the Holocene funnel-shaped bay was established in forming the topography of the present river mouth; 2) the backstepping migration of the depocenter in association with tidally-dominated sandy shoals developed in the Early-Middle Holocene, followed by fluvially-tidally dominated progradation during the Mid-Late Holocene; 3) the model of depocenter shift characterized by en-echelon sandy shoals in the incised valley, revealing stepwise migration from transgressive to retrogressive sedimentation in the Holocene, and 4) the dextral diversion of the river mouth controlled by strong tidal sedimentation in the valley and the Coriolis-driven tidal sedimentation off the valley throughout the Holocene. Our results further show that the sediment in the Holocene valley was characterized by an upward increase in foraminiferal abundance. This is a reversal of the usual pattern to the Holocene marine transgression, indicating a unique depositional setting in the valley, presumably due to higher turbidity and poor preservation caused by strong tidal currents.

这项研究基于从现有文献中收集的关键信息以及为这项研究收集的新岩心，为长江三角洲切开的山谷建立了全新世沉积模型。揭示了在切开的山谷中不同的沉积过程和机理：1）全新世前切开的山谷的重要作用，在该山谷上建立了全新世的漏斗形海湾，形成了当前河口的地形；2）沉积中心的后退迁移与全新世早期中期形成的以潮汐为主的沙滩有关，随后在新世中期晚期以潮汐为主的grad积；3）切谷中梯状沙滩特征的震源偏移模型，揭示全新世从海相沉积到渐进沉积的逐步迁移，以及4）河口的右旋分流受山谷中强烈的潮汐沉积和整个新世时期科里奥利驱动的潮汐沉积的控制。我们的结果进一步表明，全新世谷中的沉积物的特征是有孔虫的丰度增加。这是对全新世海侵的惯常模式的逆转，表明山谷中独特的沉积环境，可能是由于高潮流造成的更高的浊度和较差的保存。我们的结果进一步表明，全新世谷中的沉积物的特征是有孔虫的丰度增加。这是对全新世海侵的惯常模式的逆转，表明山谷中独特的沉积环境，可能是由于高潮流造成的更高的浊度和较差的保存。我们的结果进一步表明，全新世谷中的沉积物的特征是有孔虫的丰度增加。这是对全新世海侵的惯常模式的逆转，表明山谷中独特的沉积环境，可能是由于高潮流造成的更高的浊度和较差的保存。