摘要
记述了青海柴达木盆地侏罗系油储原油中萃取出的孢子花粉化石27属45种。基于原油中孢粉化石的研究及其与潜在油源岩中孢粉化石的对比,确定了含油区的油源岩。并根据孢子花粉母体植物所反映的古生态特征探讨了油源岩形成的环境。研究结果表明,下侏罗统小煤沟组和中侏罗统大煤沟组应为该含油区的油源岩系。研究区油源岩形成于温暖湿润气候下的湖沼环境。
Forty-five species of fossil spores and pollen referred to 27 genera extracted from the crude oil samples collected from the Jurassic reservoirs of the Qaidam Basin in Qinghai Province of China were recorded. Based on the investigations of the palynomorphs in crude oil and the comparisons with those in potential source rocks, the petroleum source rocks of the petroliferous region were determined. On the basis of the paleoecological characteristics reflected by the original plants producing the spores and pollen, the sedimentary environment of the petroleum source rocks was discussed . The main species of spores and pollen found from crude oil of the Jurassic reservoirs of the Qaidam Basin are as follows: Cyathidites minor, deicherdidites cortflexus, Dictyophyttidites harrisii, Osmundacidites wellmanii, 0. ekgans, Apiculatisporis variabilis, AcanthotrUetes midwayensis, Neo-raistrickia tnncatus, Lycopodiacidites rugidatus, Contignisporites cooksonii, Duplexisporites gyratus, D. amplectiformis, D. scanicus, Densoisporites perinatus, Protopinus scamcus, ProtopiceaexUioides, Protopodocarpus mollis, Piceites expositus, Piceaepollenites omoriciformis, Cedripites minor, Podocarpidites multesimus, P. paulus, Quadraeculina limbata, Q. enigmata, Q. minor, Chas-matosporites major, Cycadopites nitidus, C. typicus, C. subgranulosus, etc. The results indicated that the Lower Jurassic Xiaomeigou Formation and the Middle Jurassic Dameigou Formation should be the petroleum source rock series of the petroliferous region. The petroleum source rocks might have been evolved in the limnetic environment under warm and wet climatic conditions.
基金
国家自然科学基金(No.R850879)
