依据植被对气候的适应性原理,通过对辽东湾地区古近系东营组中孢粉进行气候类型划分、不同气候类型孢粉含量和相对比值综合分析,对古气候演化及其对湖平面变化的影响进行研究。结果表明:辽东湾渐新世东营期气候总体上表现为从相对干热向相对冷湿转变;气候演变存在明显的旋回特征,大致可以划分为5个气候旋回,与前人研究划分的四级层序界面吻合;气候和构造沉降控制了不同层次的湖平面变化,气候为构造沉降稳定阶段控制湖平面高频升降的主控因素,并间接控制四级层序界面的形成,同时干热气候是形成盆底扇的有利条件。
According to the adaptability of vegetation to climate including temperature and humidity,the paleoclimate evolution and its influence on lake level changes of Paleogene Dongying epoch in Liaodong Bay were researched based on the division of the pollen climate types and the comprehensive analysis of the level of pollen,and the relative ratio of different climate type pollen in study areas.The results show that the whole climate in Dongying epoch transforms from relative dry-warm to relative wet-cold gradually.Climate change is characterized by significant cycle and can be divided into five cycles,which agrees well with the four-order sequence boundary of previous studies.With the tectonic subsidence and lake level change history,it is found that the climate controls the high-frequency lake level fluctuations when tectonic subsidence is stable.At the same time,the climate also indirectly controls the four-order sequence boundary,and the dry-warm climate is favorable for the formation of basin floor fan.