Classopollis高含量带的发现及其地质意义

系统收集整理准噶尔盆地地面、井下三工河组的古生物资料，重点研究三工河组Classopollis(克拉梭粉属）高含量带的孢粉组合的分布规律，在北天山山前Classopollis高含量带地层厚度大，含量高。准噶尔盆地由南向北其含量减少，地层厚度减薄。认为Classopollis高含量带在三工河组下段顶部，与吐哈盆地煤窑沟剖面三工河组，塔里木盆地库车河剖面阳霞组上段、青海大煤沟剖面大煤沟组二、三段，民和盆地炭洞沟组上部，陕甘宁盆地南部富县组相当，反映全球托阿尔斯（Toarcian)的一次气候变干事件。Classopollis高含量带是一良好标志层，可以作为中下侏罗统划分的标志之一。

Discovery and Geological Significance of Classopollis High-Content Zone

This paper systematically collects and integrates palaeotologic information from downhole Sangonghe formation and out -crops in Junggar basin,and pays mainly attention to study of the distribution of sporopollen assemblage of Classopollis high-con-tent zone in Sangonghe formation.The results show that strata with Classopollis high-content zone are big in thickness and high in content in the foreland of North Tianshan mountain,and become thinning and reducing from the south to the north of Junggar basin.The Classopollis high-content zone in top of lower member of Sangonghe formation in Junggar basin is correlated with San-gonghe formation of Meiyaogou section in Turpan-Hami basin,upper member of Yangxia formation of Kuqa river section in Tarim basin,No.2and3members of Dameigou formation of Dameigou section in Qinghai region,upper part of Tandonggou formation in Minhe basin and Fuxian formation in southern Shaanxi-Gansu-Ningxia basin,reflecting an arid climate occurred in period of Toar-cian in the world.The Classopollis high-content zone is a good marker bed,and can be used as one of markers for distinguishing between the Middle Jurassic and the Lower Jurassic in Junggar basin.