永陇矿区东部边缘煤层底板高差缘由探究

Study on the causes of the height difference of coal seam floor in the eastern edge of Yonglong mining area

依据地质勘查基础资料,分析了永陇矿区东部的地层结构、构造演化及应力场特征,明确了边缘赋煤区煤层底板高差大的原因。研究表明:矿区东部经历了印支、燕山及喜山3期构造运动,其中印支晚期的弱褶皱作用,应力方向近似南北,造成了区内近似东西的小褶皱形成;燕山期构造最为复杂,伸展凹陷作用、挤压抬升作用交替演化,最终基本奠定构造格局;喜山期的伸展、断陷作用,促使研究区内的构造形态最终成形,东南部地层在前期抬升的基础上发生翘倾。矿区东部边缘赋煤区在挤压抬升、断陷翘倾作用的影响下,造成了煤层底板高差大的结果。

According to the basic data of geological exploration,the stratigraphic structure,tectonic evolution and stress field characteristics of the eastern part of Yonglong mining area were analyzed,and the reasons for the large height difference of coal seam floor in the marginal coal-producing area were discussed.The study shows that the eastern part of the mining area has experienced the three-phase tectonic movement of Indosinian,Yanshan and Xishan.Weak folding in late Indosinian resulted in the formation of small east-west folds in the region.Yanshanian tectonic extensional depression and extrusion uplift alternately evolved,and finally laid the tectonic framework.The extension and faulting of Himalayan period led to the final formation of the tectonic form in the study area,and the southeastern strata tilted on the basis of the earlier uplift.Under the influence of the extrusion uplift and the fault depression on the eastern margin of the mining area,the coal seam floor height difference is large.