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北黄海中部晚更新世末以来低海面时期发育的硬质粘土层是古环境变化信息的重要载体。文章运用沉积学、孢粉学和年代学等方法,从样品中提取出了可指示北黄海硬质粘土层成因的孢粉、藻类化石,并揭示了其记录的古环境和古气候特征。研究表明,该硬质粘土层的形成年龄介于12602~10357cal.a B.P.之间,年代上与发生在12.9~11.6ka期间的末次冰消新仙女木气候回冷事件相吻合,与不同沉积环境中形成的北黄海泥炭层为同一时期的沉积,可作为新仙女木事件在北黄海陆架响应的一个重要证据。高含量淡水藻类(环纹藻、盘星藻)与香蒲的存在表明北黄海硬质粘土层的形成环境主要为淡水水域,而硬质粘土层中藜科-蒿属的存在指示其形成期间间或受到海水的影响,其上下层段海生沟鞭藻含量的增加说明硬质粘土层沉积初期及形成后期海水作用的增强,淡水藻类与陆生植物孢粉此消彼长的变化规律反映了硬质粘土层形成的阶段性特征。硬质粘土层中蒿属-香蒲-松-禾本科-单缝孢和松-蒿属-禾本科-单缝孢-香蒲孢粉组合表明研究区当时处于寒冷而湿润的环境,低地为以河流湿地为主的平原草甸,周边山地有针阔叶混交林分布。北黄海晚更新世末期形成的硬质粘土层与长江三角洲地区同期形成的硬质粘土层孢粉藻类组合中均出现高含量的淡水藻类化石,而差异性体现在前者存在一定比例的蒿属藜科植物花粉,主要由两者所处的纬度不同所致。
The hard clay layer developed in the low sea level since the late Pleistocene in the northern North Yellow Sea is an important carrier of paleoenvironmental change information. Based on the methods of sedimentology, palynology and chronology, the authors extracted the sporopollen and algal fossils that could indicate the origin of the North Yellow Sea hard clay from the samples and revealed the paleoenvironment and paleoclimate recorded by them. The results show that the age of formation of the hard clay layer is between 12602 and 10357cal.a BP, coinciding with the climatic cold event of the last ice-new fairy in the age of 12.9 ~ 11.6ka, The formation of the North Yellow Sea peat layer for the same period of sedimentation can be used as a new fairy wood event in the North Yellow Sea shelf response is an important evidence. The presence of high concentrations of freshwater algae (Rings algae, Platymonas subcordyceps) and cattail showed that the formation of the North Yellow Sea hard clay was predominantly freshwater, whereas the presence of Chenopodiaceae-Artemisia in the hard clay layer was indicative of the formation of Under the influence of seawater, the increase of the content of dinoflagellates in the upper and lower layers of seaweed showed the enhancement of seawater in the early stage of sedimentation and later stage of formation of hard clay. The change law of spore powder of freshwater algae and terrestrial plants reflected the change of hard clay Layer formation of the stage characteristics. The combination of Artemisia - Typha - Pine - Poaceae - Pinus sylvestris - Artemisia - Poaceae - Monocosporidium - Typha pollen in the hard clay layer indicated that the study area was in a cold and humid environment at that time, Wetlands mainly plains meadow, surrounded by coniferous and broad-leaved mixed forest distribution. High concentrations of freshwater algae fossils occur in both the hard clay layer formed in the late Pleistocene of the North Yellow Sea and the sporopollen assemblages in the hard clay layer formed in the same period of the Yangtze River Delta while the difference is reflected in the existence of a certain proportion of Artemisia quinoa Branch plants pollen, mainly due to the latitude of the two are due to.