鄂尔多斯盆地东北部侏罗纪煤系烃源岩的分布特征

Distributing Features of Jurassic Coal Measures Hydrocarbon Source Rock in Northeastern Ordos Basin

鄂尔多斯盆地东北部是煤炭、石油、天然气、砂岩型铀矿等有机矿产共存的代表性地区之一,煤系烃源岩作为原始物质,在多种能源矿产成藏(矿)过程中起着重要作用。从煤系层序地层格架及沉积体系分析入手,分析了鄂尔多斯盆地东北部侏罗纪煤系烃源岩的种类、岩性、聚积环境、发育程度、时空分布等。结果表明,煤系烃源岩随时间在纵向上的变化与盆地的演化阶段相一致,盆地相对稳定期,烃源岩发育程度最好,初始和退覆充填期次之;空间上总体分布为由北向南,自西向东,层数增多,厚度增大。该区广泛发育的煤系烃源岩为多种能源矿产形成奠定了物质基础,其时空分布对多种能源共存成藏格局具有初始控制作用。

The northeastern Ordos Basin is a typical example of organic minerals of coal, oil, natural gas and sandstone type U-ore coexisting in the country. The coal measures hydrocarbon source rock as a primitive material plays a major role in various energy resources ore-forming processes. Start from coal measures sequence stratigraphic framework and sedimentary system analyses, discussed type, lithology, accumulating environment, developing extent, space-time distribution etc. of source rocks. The results demonstrated that the longitudinal varying of source rocks corresponded with the basin evolution as time going. The relative stable phase of the basin was the best time to develop source rocks, while the initial and offlap filling period the second. Spatially, layer number and thickness of source rocks are increasing from north to south, west to east. The vastly developed source rocks established material basis for the various energy resources ore-forming, their space-time distribution has initially controlled the ore-forming framework.