渝东北地区晚二叠世海槽形成及其对富有机质页岩发育的控制作用

发布时间：2018-06-19 07:16

  本文选题：构造演化 + 大隆组页　； 参考：《成都理工大学》2017年硕士论文

【摘要】：本文以四川盆地上二叠统大隆组富有机质页岩为研究对象,根据野外地质观测,并结合区域构造背景分析,系统的论述了渝东北地区大隆期构造特征对其页岩气发育的地质意义。针对研究区内采集的岩石样品,对其进行了岩石有机地球化学方面的测试分析,再结合前人资料,共得出以下几点认识。1、大隆组富有机质泥页岩的发育受到构造控制。主要发育在开江-梁平海槽及城口-鄂西海槽内部,而在其余地区没有发育大隆组泥页岩。2、晚二叠世,研究区内古构造格局为“两隆两凹”古地貌格局为“三缘两高”。开江-梁平海槽及城口-鄂西海槽的形成是在南秦岭洋拉张背景下,扬子板块内部峨嵋地裂运动及基底断裂的共同作用下形成的。3、海槽的形成对大隆组的控制具体表现在:晚二叠世由三种构造运动综合作用下形成的海槽,导致了大隆组沉积时的深水环境,大隆组的沉积环境控制了大隆组富有机质页岩的发育、分布及其有机质特征。4、根据岩石颜色,岩石结构构造,岩石组合类型等标志,可将大隆组所沉积的深水环境划分出盆地相和陆棚相两大沉积。大隆组中富有机质泥页岩主要发育于陆棚相,主要为硅质泥岩,泥质灰岩,泥岩,砂质泥岩及钙质泥岩等。5、大隆组矿物组分主要为粘土和脆性矿物,碳酸盐矿物含量相对较低。脆性矿物以石英为主,粘土矿物主要为伊利石、伊蒙混层和绿泥石,碳酸盐矿物以方解石为主。6、大隆组富有机质页岩的有机质类型主要为Ⅱ型有机质,主要显微组分为腐泥组,约占显微组分的60%~80%。干酪根主要为Ⅱ1型,少量为Ⅱ2型。大隆组泥页岩中Ro值有机质的成熟度已达高-过成熟阶段,多数为2.0-3.0%,对页岩气的形成十分有利,总有机碳含量较高量,主要分布于2%-4%,及6%的区间,具有良好的生烃潜力。
[Abstract]:In this paper, the organic shale of the Upper Permian Dalong formation in Sichuan Basin is taken as the research object, according to the field geological observation and the analysis of the regional tectonic background, This paper systematically discusses the geological significance of the structural characteristics of the Dalong period to the development of shale gas in northeast Chongqing. According to the rock samples collected in the study area, the organic geochemistry of the rocks was tested and analyzed. Combining with the previous data, it was concluded that the development of the organic matte shale in the Dalong formation was controlled by the structure. It is mainly developed in Kaijiang-Liangping trough and Chengkou-western Hubei trough, while in other areas there is no mud shale .2. late Permian. The paleotectonic pattern in the study area is "two uplift and two depression" paleogeomorphology pattern is "three margins and two heights". The formation of the Kaijiang-Liangping trough and the Chengkou-Western Hubei trough is under the background of the South Qinling Ocean extension. The formation of the trough controlled the Dalong formation by the combined action of the Emei tectonic movement and the basement fault in the Yangtze plate: the trough formed under the combined action of three tectonic movements in the late Permian, The depositional environment of the Dalong formation controls the development, distribution and organic matter characteristics of the organic shale in the Dalong formation, according to the color of the rock, the structure of the rock, the type of the rock assemblage, and so on, the sedimentary environment of the Dalong formation controls the development, distribution and organic matter characteristics of the organic shale of the Dalong formation. Deepwater environment of Dalong formation can be divided into basin facies and shelf facies. The organic matter rich mud shale in Dalong formation is mainly developed in continental shelf facies, mainly composed of siliceous mudstone, argillaceous limestone, mudstone, sandy mudstone and calcareous mudstone, etc. The mineral components of Dalong formation are mainly clay and brittle minerals, and the carbonate mineral content is relatively low. The brittle minerals are mainly quartz, the clay minerals are mainly Illite, Illite, and chlorite, and the carbonate minerals are calcite. 6. The organic matter type of organic shale in Dalong formation is mainly type 鈪，

本文编号：2039072