黔西地区构造演化及其对晚二叠世煤层的控制

Structure Evolution in West of Guizhou Area and Control to Seam in Late Permian

黔西地区构造复杂,严重制约了煤田的勘探与开发,为此,以区域构造演化为主线,结合野外地质和煤田勘探资料分析,对黔西地区构造演化及煤层聚集和赋存的构造控制进行深入的探讨。结果表明:黔西地区构造演化经历了6个阶段:基底形成阶段、被动大陆边缘阶段、陆内裂陷阶段、稳定台地阶段、陆内造山阶段和挤压隆升阶段;受NE、NNE向同沉积断裂及东吴运动形成的北西高南东低的古地形控制,晚二叠世时沉积了一套海陆过渡相为主的含煤建造,沉积相带由NW至SE呈NE向规律性展布,成煤期后受燕山运动和喜马拉雅运动影响,原型煤盆地遭受强烈破坏,大型向斜和复向斜成为最重要的控煤构造。

The structures in West Guizhou were complicated and seriously restrained the exploration and development of the coalfield. Thus, taking the regional structure evolution as the main line, in combination with the analysis on the field geological and coalfield exploration information, a detail discussion was conducted on the structure evolution and the structure control of the seam accumulation and deposit. The results showed that the structure evolution of West Guizhou had experienced with six stages, including the base formation stage, passive continental margin stage, inland rift-depression stage, steady platform stage, intracontinental orogenic stage and compressing and uplifting stage. Controlled by the NE and NNE synsedimentary faults and the paleotopography with high in northwest and low in southeast formatted by the Dongwu movement, a coal bearing structure mainly with set of the marine-continental transitional facies was deposited in Late Permian. The sedimentation facies was expanded in NE direction from NW to SE. After the coal formation period, the original type coal basin was seriously decomposed by the influences of the Yanshan movement and the Himalayan movement. The large syncline and synclinorium would be the main coal controlled structure.