苏北盆地溱潼凹陷第三系烃源岩地球化学特征

溱潼凹陷第三系主要分布有戴南组一段、阜宁组四、三、二、一段和泰州组6套烃源岩层.通过地球化学的方法研究了溱潼凹陷主要烃源岩的分布特征、有机质丰度、类型及热演化程度,描述了烃源岩中有机质族组成、甾烷和三萜烷系列化合物分布特征等,分析了不同层位烃源岩的母质类型、沉积环境及有机质演化规律.并根据生物标志物组合特征将烃源岩划分成A、B、C3类,A类烃源岩形成于相对咸化的还原环境,生源以低等水生藻类为主,为研究区的优质烃源岩,主要分布在泰州组二段、阜宁组二段中—下部和阜四段上部.

Geochemical characteristics of the lower tertiary source rock in Qintong Sag, Subei Basin

There are mainly six sets of source rocks in the Tertiary in Qintong Sag,including the 1th member of Dainan formation,the 1th member,the 2th member,the 3th member and the 4th member of Funing formation and Taizhou formation.The distribution feature of main source rocks,the content,types and thermal evolution degree of the organic matter in these source rocks are studied by geochemical method.The composition of the organic matter and the distribution characteristics of sterane and triterpane series compounds are described.The kerogen types and depositional environment of the source rocks and the evolution law are analyzed.The source rocks are divided into three types of A,B and C according to the association characteristics of their biomarkers.The study result shows that the A type of source rocks is formed in a salinizing reduction environment.This type of source rocks is the high-quality source rocks in the studied area,and its biogenesis is mainly lower aquatic algae.The type of source rocks distributes mainly in the 2th member of Taizhou formation,the middle part and lower part of the 2th member and the top of the 4th member of Funing formation in Qintong Sag.