论文部分内容阅读
在观察兴县关家崖野外露头剖面马五_5亚段核形石灰岩岩性特征的基础上,进行了薄片镜下鉴定,开展了全岩X衍射,主、微量元素,锶和碳、氧稳定同位素及有机碳分析。研究结果表明,核形石灰岩形成于开阔海环境,准同生阶段核形石发生重结晶作用,浅埋藏期压实作用使巨晶方解石呈镶嵌接触并产生压力双晶纹;马五_5亚段底部核形石灰岩形成于海平面上升过程,未受早期淡水溶蚀;马五_5亚段顶部核形石灰岩形成于海平面下降过程,明显受早期大气淡水淋滤与溶蚀作用影响;在中—深埋藏阶段受地下热液影响,在水-岩作用过程中发生了同位素交换及有机质成熟及排烃作用。该套核形石灰岩的发现,明确了马五_5亚段形成于开阔海环境,这对于马家沟组烃源岩的研究具有参考意义。
On the basis of observing the lithology of karst limestone in the fifth member of Mawu-5 in the outcrop profile of Guanjiaya of Xingxian County, X-ray diffraction, primary and trace elements, strontium, carbon and oxygen stable isotopes And organic carbon analysis. The results show that the formation of karyolite limestone in the open sea environment, quasi-syngenetic stage nucleation stone recrystallization, compaction during shallow burial period of the giant crystal calcite was inlaid contact and produce pressure twin grain; At the bottom of the segment, the karyolite formed at sea level rising without being affected by the early fresh water erosion. At the top of the M15 sub-segment, the karyotype limestone formed in the sea level descending process, which was obviously affected by the early atmospheric freshwater leaching and dissolution. The stage is affected by underground hydrothermal fluids. During the water-rock interaction, isotopic exchange and organic maturation and hydrocarbon expulsion occur. The discovery of this set of core limestone made it clear that the formation of the Mawu-5 sub-zone in an open sea environment has a reference meaning for the study of Majiagou source rock.