塔里木盆地下寒武统底部高熟海相烃源岩中有机质的赋存状态

Occurrence of High Mature Organic Matter in Marine Black Shale Source Rocks of Lower Cambrian from Northern Tarim Basin,China

近年来的研究证明 ,中新生代未熟 -低熟海相富有机质泥质烃源岩中有机质是通过溶解在水中的分子规模的碳有机质以化学吸附的形式被吸附到矿物表面上和蒙脱石结构层内 .然而 ,对于高熟海相泥质烃源岩中有机质的赋存状态却少有报道 .通过对塔里木盆地下寒统底部高熟海相泥质烃源岩的有机碳含量、矿物表面积、扫描电镜和透射电镜的综合分析 ,得到了其有机质以细小的颗粒状保存于沉积物颗粒之间的结论 .同时 ,通过高熟海相烃源岩与现代未熟海相烃源岩有机质赋存状态的对比 ,提出了值得进一步研究的有关科学问题 .

More and more evidences indicate that the organic matter (OM) in immature organic-rich sediments and sedimentary rocks is chemically absorbed onto the external surfaces of minerals and into interlayer (internal) surfaces of smectitic clay minerals in the form of amorphous molecular scale carbon OM. But there are few reports about the occurrence of high mature OM in marine black shale petroleum source rocks. This paper studies the occurrence of high mature OM in the black shale of basal Cambrian from the northern Tarim basin. Based on the comprehensive analysis of total organic carbon contents (TOC), maximum thermolysis temperatures (T_(max)) of OM, mineral surface areas (MSA), scanning electronic microscope (SEM) and transmission electronic microscope (TEM) of the black shale, it concludes that the high mature OM in the marine black shale of the basal Cambrian from the basin occurs in the state of particulates ranging from 1 to 5 microns in diameter. The contrast of the existing state of the high mature OM in the black shale with that of the immature one in the modern marine continental margin sediments has brought some scientific problems, which are valuable to study in detail.