【作者】 孙国智；

【导师】 柳益群；

【作者基本信息】 西北大学 ， 矿物学、岩石学、矿床学， 2009， 硕士

【摘要】 石炭系是北疆地区一套新的油气勘探层系,近年来在三塘湖、准噶尔盆地勘探成果显著,但在吐哈盆地及邻区石炭系研究程度较低。博格达构造带横亘于准噶尔盆地和吐哈盆地之间,其主体部分由石炭系构成,对研究吐哈盆地石炭系有重要意义。本文以板块构造、构造地质学、沉积学理论为指导,综合利用地层学、地球化学、岩相学等方法,对博格达地区石炭纪原型盆地进行研究分析,为吐哈盆地石炭系油气勘探提供基础资料。根据岩石组合特征、生物群面貌、地层接触关系等将博格达地区石炭系自下而上划分为下石炭统塔普捷尔泉组,七角井组,上石炭统柳树沟组,祁家沟组和奥尔吐组。结合博格达构造带内的地层接触关系和盆地内地震资料解释成果,将吐哈盆地的C-P₁一级构造层划分为下石炭统亚构造层序,上石炭统柳树沟组亚构造层序,上石炭统祁家沟组-奥尔吐组亚构造层序和下二叠统亚构造层序。火山岩的岩相学、矿物学特征及主量元素、微量元素、稀土元素等地球化学特征表明博格达地区的火山岩与大陆裂谷火山岩的特征相一致。古流向及物源区母岩特征表明博格达地区石炭纪的物源来自准噶尔古隆起和吐哈古隆起、早石炭世晚期隆起的克拉美丽-莫钦乌拉构造带以及晚石炭世晚期盆地内部的局部隆起区。通过野外实测剖面和室内分析划分了沉积相,以此为基础,以裂谷的构造格局为框架,结合物源区特征,对博格达地区石炭纪原型盆地的沉积格局进行分析,认为博格达地区石炭纪的大部分地区和大部分时间为滨浅海相沉积,半深海-深海相主要发育在柳树沟组时期的博格达轴部以及奥尔吐组时期的博格达地区西部,地层主要呈东西向展布。晚石炭世奥尔吐组时期,博格达地区出现东西差异。博格达地区潜在的烃源岩主要为七角井以北地区由半深海-深海环境控制的柳树沟组暗色泥岩和哈密北部石城子地区由滨浅海环境控制暗色泥岩。研究区暗色泥岩为以Ⅱ型干酪根为主的好-差烃源岩,多处于过成熟阶段。更多还原

【Abstract】 The Carboniferous of Xinjiang, Northern-west China is a new exploration target layer, and significant exploration discoverments have been achieved in Santanghu Basin and Junggar Basin. Because of the low study level of Carboniferous in Turpan-Hami basin and adjacent areas, Carboniferous oil and gas exploration progress here is very slow. Bogda Tectonic Belt, which mainly composed of the Carboniferous, is located between the Junggar basin and Turpan-Hami basin, and has an important significant study meaning to Turpan-Hami Basins. According the Plate Tectonics, Structural Geology, Sedimentology Theory as a guide, utilizing the stratigraphy, geochemistry, petrography Stratigraphy, Structural Geology, Sedimentology, the Carboniferous prototype basin of Bogda region is analysised by the article, which provides the oil and gas exploration and development basis to the Carboniferous of Turpan-Hami Basin.According to the rock association characteristics, biological group characteristics, stratigraphic contact relations, the Carboniferous in Bogda region could be divided into Lower Carboniferous: Tapujieerquan Group and Qijiaojing Group, Upper Carboniferous: Liushugou Group, Qijiagou Group and Aoertu Group from below. The C-P₁ tectonic sequence could be divided into sub-Carboniferous tectonic sequence, Upper Carboniferous Formation Liushugou tectonic sequence, Upper Carboniferous Formation Qijiagou-Aoertu tectonic sequence sub-groups and sub-Lower Permian tectonic sequence by the stratigraphic contact relations and interpretation results of seismic data in the basin.Petrography of volcanic rocks, mineralogical characteristics and major elements, trace elements, REE and other geochemical characteristics of volcanic rocks in the region show that volcanic rocks of Bogda region has the consistent characteristics of mainland rift valley.The characteristics of ancient flow and the mother rock in source region show that Carboniferous source of Bogda region were from Junggar ancient land and Turpan-Hami Ancient Land, Kelameili - Moqinwulashan Tectonic Belt which uplifted in the late Early Carboniferous and the uplift region within the basin in late Late Carboniferous. Based on facies marks, which is established by the field measured profiles analysis and laboratory-office analysis, Bogda Rift Valley, which is a framework combined with the characteristics of source area, the Carboniferous sedimentary pattern of prototype basin in Bogda region is completed. The deposition is littoral-neritic facies in most area of the Bogda region and most time of the Carboniferous. Semi-deep sea - the deep sea sediment was developed in the axis of Bogda Rift Valley of the Liushugou period, and in the western region of Bogda region of Aoertu period. The stratigraphic distribution was developed mainly by east-west. In the Aoertu period, Late Carboniferous, differences between East and West of Bogda regions came out. The potential source rocks of Bogda areas are dark mudstone which were mainly distributed in the north area of Qijiaojing County of Liushugou Formation and Shichengzi regions located to the north of Hami City of Qijiagou Formation. They are controlled by half deep - deep-sea and littoral-neritic environment respectively. The dark mudstone is mainly II kerogen type and belongs to good - poor source rocks, most of them had been over matured.更多还原