Characteristics Of Nappe Structure And Coal Prospecting In Liuyang-Liling District, Northeast Hunan

Based on the coalfield structure and the actual demand of coal prospecting in Liuyang-Liling area, Northeastern Hunan, we take the structural geology theory as the guide, taking the research of coal-controlled structure as the core, and taking the computer technology as the main tool to do the job. We do the research through the combination between the deep structure and the shallow structure, the macroscopic structure and the microstructure, the qualitative analysis and the quantitative evaluation, the morphological study and the genetic study from the known area to the unknown area. According to the condition of coal occurrence and the characteristics of distribution of sedimentary structure and faulted structure, we divide the Liuyang-Liling area into three different deformation zone. From this we know the structural feature of each part.The area of Northeastern Hunan is compressional tectonic pattern, so the deformation is strong and the tectonic style is complicated. The main structure line distribution and regional stratigraphy with NNE-trending to SSW-trending, associated with NNE-trending folds and fractures, are cutted by fractures from every direction, therefore, we can find the tectonic pattern with the alternation between basin and uplift. The fracture, with mutiperiodic activity, is the main structure in coalfield tectonic pattern, especially the compressoshear reverse fault, which has the obvious composite characters of piezotropy, torsional pressure and extensional pressure. Nappe structure develops and its direction may be from southeast to northwest, but it probably transformed by a group of NNE-trending imbricate faults with southeast-trending thrust-napped structures after Jurassic Period. Therefore, we can focus on the coal system which underlying nappe tectonic system in coal prospecting works. The compressional tectonic pattern is the main structure style in Liuyang-Liling area, Northeastern Hunan. The thrust fault fold tectonic pattern and thrust nappe tectonic pattern are the most developing, so they are the main coal control structure. This paper put forward two one-level target section-Baitutan, Chengtanjiang and three two-level target sectionO-Wenjiashi, Nanqiao and Zhangjiachong from the basis of the structural control of coal.