宣东二号煤矿滑脱构造特征及其形成机制探讨

据钻探资料分析,宣东二号煤矿发育有以F2为主滑脱面的滑覆型滑脱构造,滑脱面主要发育在下花园组煤系中,上覆系统包括Ⅲ3煤层及其以上地层,而Ⅳ1煤层及其以下地层则构成下伏系统。区内滑脱构造属于鸡鸣山—黄羊山推覆构造伴生的次一级构造,它的发育使部分压应力得到释放,从而使煤层避免了类似下花园附近的强烈褶皱和断裂。发育于Ⅲ3等煤层内部的滑脱构造,导致了煤变质程度的提高和物理力学性质的改变。

Discussion on Decollement Structure Features and Their Formation Mechanism in Xuandong No.2 Coalmine

Based on drilling data analyses a slip thrust decollement structure has found and to take the F2 as the main decollement surface developed mainly in the Xiahuayuan Formation coal measures. The overlying system includes coal seam III3 and strata above, while the coal seam IV1 and strata below the underlying system. Decollement structure in the area belongs to a secondary structure associated with the Jimingshan-Huangyangshan nappe structure; its development has released a part of compressive stress and avoided strong folding and faulting of coal seams analogous to those in Xiahuayuan close proximity. Decollement structure developed in coal seams III3 and others caused the higher coal metamorphism and changing of physical and mechanical properties.