Distribution of pollen grains in sediment core T89-16-PC (Table 2)

High abundances of mangrove pollen have been associated with transgressive cycles on tropical margins, but the detailed relations between systems tracts and the taphonomy of the pollen are unclear. We report here the occurrence and high abundance of Rhizophora pollen, in association with taraxerol, a Rhizophora-sourced biomarker, from a high-resolution Congo fan core covering the last deglaciation. An age model based on 14C dates enables the temporal changes in taraxerol content and the percentage frequencies and flux (pollen grains (pg)/cm**2/(10**3 yr)) of mangrove pollen to be compared quantitatively with the lateral rate of transgression across the flooding surface (derived from glacio-hydro-isostatic model output and the bathymetry of the margin). Rhizophora pollen concentrations and taraxerol content of the sediment are very strongly positively correlated with the lateral rate of transgression and indicate, independently of any sequence stratigraphic context, that mangrove pollen spikes are associated with the transgressive systems tract rather than the highstand systems tract or maximum flooding surface. Lower-resolution longer-term records from this margin indicate an association between taraxerol concentrations and transgressive rather than regressive phases. The flux of these materials to the Congo fan is interpreted as a function of the erosion of flooded mangrove swamp on the shelf and, less importantly, changing extent of mangrove habitat, during sea-level rise. Congo River palaeoflood events also result in reworking of mangrove pollen and supply to the fan, but this mechanism is subdominant. Rhizophora pollen has been underestimated in many palynological studies undertaken on cores from the African margin because of inappropriate sieve mesh size used during laboratory preparation.红树林花粉的高丰度与热带陆缘的海侵旋回存在关联，但体系域（systems tracts）与花粉埋藏学（taphonomy）之间的具体关联仍不明确。本文报道了采自覆盖末次冰消期的高分辨率刚果扇岩心中的红树属（Rhizophora）花粉的产出与高丰度特征，其与红树属来源的生物标志物（biomarker）蒲公英赛醇（taraxerol）伴生。基于14C测年（14C dates）建立的年代模型（age model），可将蒲公英赛醇含量、红树林花粉的百分频率与通量（花粉粒数/平方厘米/（10³年））的时间变化，与洪泛面（flooding surface）处的海侵侧向速率（由冰川-水均衡模型（glacio-hydro-isostatic model）输出与陆缘水深地形（bathymetry）推导得到）进行定量对比。沉积物中的红树属花粉浓度与蒲公英赛醇含量与海侵侧向速率呈极强的正相关，且独立于任何层序地层背景（sequence stratigraphic context），表明红树林花粉峰值与海侵体系域（transgressive systems tract）相关，而非高位体系域（highstand systems tract）或最大洪泛面（maximum flooding surface）。该陆缘的低分辨率长期记录显示，蒲公英赛醇浓度与海侵阶段而非海退阶段（regressive phases）存在关联。这些物质向刚果扇的通量被解释为：海平面上升过程中，陆架（shelf）上被淹没的红树林沼泽的侵蚀为主导因素，红树林生境范围的变化则为次要因素。刚果河古洪水事件（Congo River palaeoflood events）同样会导致红树林花粉的再搬运（reworking）并向扇体输送，但该机制占比偏低。由于实验室前处理阶段使用的筛网孔径（sieve mesh size）不当，在非洲陆缘岩心开展的诸多孢粉学研究（palynological studies）中，红树属花粉的丰度被低估了。