太行山构造演化对焦作矿区瓦斯赋存的控制研究

Study on Taihang Mountain structure evolution affected to control of gas deposition in Jiaozuo Mining Area

为揭示焦作矿区二1煤层瓦斯赋存规律,运用瓦斯地质理论和区域构造演化理论,研究了太行山山前断裂带构造演化及其对焦作矿区煤层瓦斯生成、运移、保存的控制作用。结果表明:区域岩浆热变质作用使二1煤层达到高变质无烟煤,瓦斯大量生成;而晚侏罗世的地壳抬升作用使瓦斯大量逸散;新构造期的沉降作用以及水文地质条件对瓦斯保存有利,是矿区瓦斯普遍较高的主要原因。近似EW向断层在历次构造演化期对瓦斯具有较好的保存作用,但新构造期对瓦斯有短暂的释放,断层两侧250 m范围瓦斯含量下降;NE向断层发育较广且受多期次挤压、剪切构造作用的改造,对瓦斯保存以及构造煤的形成有利。

In order to reveal a gas occurrence law of No. 21 seam in Jiaozuo Mining Area,a gas geological theory and regional tectonic evolution were applied to study the tectonic evolution of the fault zone in front of Taihang Mountain and the control role to the seam gas formation,migration and preservation in Jiaozuo Mining Area. The results showed that the thermal metamorphism of the regional magma caused No. 21 seam to be high metamorphism anthracite and great gas was formed. The lifting role of the Late Jurassic crust made the gas dissipation highly. The sedimentation role of the new tectonic period and the hydrogeological condition would be favorable to the gas preservation and were the main cause of the high gas content in the mining area. After several tectonic evolution periods,the EW directional fault could have good preservation role to the gas,the new tectonic period had a short period releasing of the gas and the gas in the two sides with a scope of 250 m of the fault was reduced. The NE directional fault was widely developed,was reconstructed with several extrusions and shearing tectonic role and would be favorable to the gas preservation and tectonic coal formation.