摘要
本文通过对长江口砂坝地区的三个钻孔的岩性岩相结构特征和微体古生物综合分析,在全新世地层中发现有四个沉积层和相应的四个微体化石层。它们分别指示了该地层经历了(由下往上)由滨海—河流相→滨海—河口相→浅海相→河口相的环境演变过程;古气候则显示为从温凉干旱→湿暖略干→暖热湿润→温暖湿润四次波动发展过程:并认为该区全新世地层可以四分,即古全新世、早全新世,中全新世、晚全新世。
According to the distribution of microfauna assemblages of the column profile from bottom to top, the sediments of Holocene in the mouth bars of the Changjiang estuary may be divided into four microfauna assemblages as follows: 1, Elphidium magella nicum-A m m onia beccarii var. -Cribrononion subincertum assemblage. 2, Ammonia beccarii var. -Elphidium magellanicum-Pseudononionella variabilis assemblage. 3, Ammonia beccarii var. -Epistominella naraensis-Florilus decorus assemblage. 4, Epistominella naraensis-Ammonia beccarii convexidorsa assemblage. Based on the anelysis of microfauna, sporepollen and C^(14)dating data, the paogeographic environment of theChangjiang estuary in the Holocene can be devided into four development stagges.
关键词
长江口
全新世
古地理
古生物
沉积
Changjiang estuary Sands Holocene Paleogeoraphy Microfauna
