山东东部白垩系莱阳群沉积地层与有机质特征

为了解山东东部白垩系莱阳群沉积地层,研究有机质特征,在对灵山岛、崂山垭口—八仙墩及胶莱盆地的典型剖面地层野外踏勘的基础上,结合灵山岛元素地球化学、胶莱盆地有机地球化学的相关研究成果,采用了沉积学、沉积地球化学、有机地球化学的研究方法手段,系统研究了灵山岛莱阳群地层的有机质特征。胶莱盆地早白垩世莱阳期主要发育一套河湖相及冲积扇相的陆相沉积地层,有机地球化学研究表明,其水南段烃源岩样品主要为腐泥型(Ⅰ型)和腐殖腐泥型(Ⅱ_1型),已进入生烃门限,处于热演化成熟阶段;而灵山岛、崂山垭口-八仙墩早白垩世莱阳期则主要发育深水重力流、深水牵引流为主的海相沉积地层,对灵山岛粉砂岩和页岩进行元素地球化学研究指示了其沉积环境为海相还原环境,且有机地球化学研究表明,灵山岛样品为腐殖型(Ⅲ型)和腐殖腐泥型(Ⅱ1型),处于高成熟到过成熟阶段,灵山岛浊积岩可能已经完成了生排烃过程。

Sedimentary strata and organic matter features of the Cretaceous Laiyang Group in eastern Shandong Province

The organic matter features of the Laiyang Group in Lingshan Island were systematically studied by means of sedimentology, sedimentary geochemistry and organic geochemistry and integrating with typical outcrop observation in Lingshan Island,Laoshan Yakou-Baxiandun area and Jiaolai Basin and the previous research on the elemental geochemistry of Lingshan Island and the organic geochemistry of Jiaolai Basin. In Jiaolai Basin,the terrestrial strata of fluvial and lacustrine facies and alluvial fan facies were developed in the Early Cretaceous Laiyang period.The organic geochemistry studies on the deposits show that the source rock samples from the Shuinan section are mainly of saprolite(Type Ⅰ)and humus and saprolite (Type Ⅱ₁),have entered the hydrocarbon generation threshold and are in the thermal mature stage;while in the Lingshan Island,LaoshanYakou-Baxiandun areas,marine strata dominated by deep sea gravity flow and deep water traction current deposits were developed in the Early Cretaceous Laiyang period.Meanwhile the elemental geochemical studies on siltstones and shales of Lingshan Island reveal that its sedimentary setting is a marine reducing environment,and the organic geochemical research shows that samples from Lingshan Island belong to the humic(Type Ⅲ)and humic and sapropel (Type Ⅱ₁)types in high to over mature stage,and the turbidites of Lingshan Island may have completed the process of hydrocarbon generation and expulsion.