渤海辽中凹陷古近系孢粉组合带及地层划分

THE PALEOGENE PALYNOLOGICAL ASSEMBLAGES AND STRATIGRAPHIC SUBDIVISION OF THE LIAOZHONG SAG,BOHAI,CHINA

利用孢粉图示、Q型系统聚类分析等方法,对辽中凹陷JZ16-4-1,JZ21-1-1,JZ25-1-3,JZ31-2E-1等钻井的206块样品进行孢粉分析,结果显示:辽中坳陷古近系沙三段到东营组一段划分为6个孢粉组合带;结合渤海湾盆地其它凹陷的古近系孢粉地层研究发现辽中凹陷东营组孢粉组合带与南堡凹陷和冀中拗陷分带结果较为相似,与黄河口凹陷和东濮凹陷有较大差异;孢粉组合带特征表明,辽中凹陷古近系气候以温暖湿润为主,略有波动,是形成孢粉分带的主要原因。

This paper analyzed 206 palynological samples from 4 wells of the Shahejie and Dongying formations in the I.iaozhong Sag, Bohai, China. The sporo-pollen of the Liaozhong Sag can be classified into 6 pollen zones, indicating 6 vegetational stages. The sporo-pollen assemblages in the Liaozhong Sag are roughly similar to those of the Nanbao Sag and the Jizhong Depression, different from those of the Huanghekou Sag and Dongpu Sag. A warm and mild wet paleoclimate with some fluctuations was implied during the Paleogene, which lead to the different sporo-pollen zones.