莱州湾南岸滨海平原晚更新世以来古环境演变的孢粉记录

依据莱州湾南岸A1钻孔孢粉分析，结合14C、热释光测年、沉积物粒度、岩性等资料，对A1钻孔自下而上划分为7个孢粉组合带，并概括它们的主要特征。利用孢粉组合，探讨了120 ka BP 以来莱州湾南岸咸水入侵区的植被发展以及气候的冷暖、干湿交替变化。在85～76 ka BP、50～24 ka BP和10～4 ka BP出现三次暖湿期，分别对应于“羊口海侵”、“广饶海侵”和“垦利海侵”。在三次暖湿期中发生海陆交互相滨岸沼泽或湖泊相沉积，植被类型为落叶阔叶林或针阔叶混交林滨岸草原。在76～50 ka BP和24～10 ka BP两次冷干期为陆相沉积环境，前者出现以针叶林为主的草原植被类型，后者出现干冷的针叶林干旱草原或荒漠草原植被类型，它们分别对应于早大理亚冰期和晚大理亚冰期。孢粉组合所反映的莱州湾南岸晚更新世以来的环境演化同全球性的气候事件及渤海沿岸环境变化具有很好的可比性。

Spore-pollen records of environmental change on south coast plain of Laizhou Bay since the Late Pleistocene

The south coast of Laizhou Bay is one of the most typical areas of salt water intrusion, which has a close relation with the environmental evolution since the Late Pleistocene This paper deals mainly with the systematic palynological and sedimentologic studies on 25 samples since the Late Pleistocene from a 29 m column core A1 According to the spore pollen diagram, 7 assemblage zones have been distinguished, and the paleo vegetation and paleoclimatic fluctuations are discussed There were three warm and wet periods since 120 ka BP， that is 85～76 ka BP, 50～24 ka BP and 10～4 ka BP, coeval to Yangkou seawater transgression, Guangrao seawater transgression and Kenli seawater transgression respectively The depositional types were paralic swamp or lake during these periods, and the main vegetational types were coastal steppes with deciduous broad leaved forest or needle broad leaved mixed forest Two cold and dry periods were 76～50 ka BP and 24～10 ka P, coeval to early Dali glacial epoch and late Dali glacial epoch, which were dominated by continental environments. The main vegetational types were needle leaved forest steppe and needle leaved forest arid steppe or hungriness steppe The environmental change stages based on spore pollen records on south coast of the Laizhou Bay since the Late Pleistocene are consistent with global climate events as well as the environmental change stages around the Bohai Sea