【作者】 杨永军；

【导师】 林丽；

【作者基本信息】 成都理工大学 ， 古生物学与地层学， 2010， 硕士

【摘要】 经过勘探实践和科学研究,下寒武统牛蹄塘组烃源岩已经引起了广泛的重视。不少学者认为下寒武统牛蹄塘组的烃源岩其有机质丰度高,属较好烃源岩,并且认为黔北地区下寒武统中的油气资源是十分丰富的,近期有望突破的重点地区。对华南油气资源的研究是目前地学领域的研究热点之一。本文主要研究了贵州遵义松林地区的寒武系牛蹄塘组下部烃源岩的沉积学及地球化学特征。主要从该地区早寒武世烃源岩的元素地球化学、有机地球化学以及有机岩石学特征的角度入手,探讨了研究区烃源岩的形成背景、有机质富集程度、有机质的输入母源、有机质的类型、有机质的成熟度、有机质的生烃潜力,从而对遵义松林地区的寒武系牛蹄塘组下部烃源岩做出综合的评价,取得了如下认识:(1)遵义地区的下寒武统牛蹄塘组烃源岩为一套由碳质页岩、结晶灰岩以及磷块岩所构成的岩性组合,其中磷块岩的分布不稳定,在松林穹窿背斜的南翼较薄,有的局部被歼灭,产生于潮坪区。灰黑色、黑色高碳质页岩或碳质泥岩页岩分布连续,厚度不稳定。泥、页岩中的镍、钼矿层呈薄层状产出,厚度总体分布连续、稳定。在泥、页岩的特定层位有磷结核分布。牛蹄塘组底部的含矿层以下的泥、页岩以及结晶灰岩形成在内陆棚的环境,牛蹄塘组底部含矿层以上及牛蹄塘组中部的泥、页岩形成在陆棚水体较深的沉积环境。(2)通过对微量元素地球化学的研究表明,研究区岩系沉积环境为缺氧还原环境,在此环境下所形成的有机质易于保存,而且类型较好。岩系具有热水沉积特点,可见热液活动提供了丰富的物质来源。(3)对岩系样品进行了可溶有机质的抽提,检测出了丰富的正构烷烃、类异戊二烯烃、萜类化合物和甾类化合物。对这些生物标志化合物参数的研究表明,研究区有机质来源于菌藻类等低等海洋生物物质,有机质类型较好;岩系的沉积环境为缺氧、强还原、低Eh、高盐度环境;有机质热演化程度较高,一般已经达到了生油门限或高成熟的阶段。(4)通过对岩系样品的有机碳测试分析并对其数值加以恢复,得出岩系有机碳含量较高,有机质丰度好,达到了好的烃源岩的标准。干酪根显微组分含量和干酪根碳同位素的含量都表明干酪根为Ⅰ型。此类型干酪根与细菌和藻类有关,这与有机地球化学指标反应的是一致的。岩系样品等效镜质体反射率都大于3.1‰说明烃源岩有机质热演化程度较高,处于高成熟或过成熟阶段。通过对有机质的丰度、类型、成熟度以及生烃潜力等方面进行评价,确定贵州遵义松林地区早寒武世牛蹄塘组下部岩系是一套良好的烃源岩。更多还原

【Abstract】 After the exploration and research, the source rocks of lower Cambrian Niutitang formation has caused much attention . A few scholars judged that the source rocks of lower Cambrian Niutitang formation get a high organic matter abundance , belong to good source rocks, they also judged that its hydrocarbon resources are rich, it will be an important area to be developed in the near future. The research of hydrocarbon resources in south China is one of the hot topic in the forefront area of geology . The paper mainly studies the sedimentology and geochemistry of the source rocks of lower Cambrian Niutitang Formation in Songlin Zunyi area of Guizhou province. Based on the element geochemistry, organic geochemistry and organic petrology , we discussed the formation background of the source rocks, the type/input/ maturity/ abundance/hydrocarbon bearing ability of the organic matter of the source rocks. The main conclusions are as following:(1)The rock series of Niutitang Formation which consist of phosphate rock, crystalline limestone,carbonaceous shales and crystalline limestone. phosphate rock distribute are not steady ,and it is thin of the south of anticline in zunyi cove and it is not discover in somewhere. Carbon shale distribute are continuously and thickness is fluctuate. The Ni-Mo ore in mudstone and shale out put thinly, the thickness distribution is continuous and steady. There are phosphate nodules in certain position. The rock series below the mine formed in the continental shelf environment, and those above the mine formed in the deep continental shelf.(2)Based on the research of the characteristic of the element geochemistry, we can draw the conclusion that the black rock series deposited in a anaerobic and reducing environment in which the organic matter is preserved easily. The rocks series has the characteristic of hot water deposit.(3)We extracted plenty of normal paraffin hydrocarbons, isoprenoid, terpenoid and steride from the samples of the black rock series. According to the research of parameters of biomarkers, we concluded that the organic matter originated from homoneneae, with good type. The rock series deposited in a anaerobic、reducing、low Eh and high salinity environment in which the organic matter is preserved easily .And the organic matter is of high mature.(4)Analyzing on the TOC of the sample, it indicates that the black rock series is of high TOC, with abundant organic matter. Contrasting the standard, we think the rock series are good source rocks. According to content of the kerogen’s maceral and carbon isotope, the kerogen is typeⅠ. This type of kerogen has something to do with bacterium and algae, which is accordant with organic geochemistly index. The R0 of rock sample shows that the organic matter is of high mature. we concluded that the rock series is good source rocks by researching the abundance/type/mature/ hydrocarbon bearing ability.更多还原