西马坊断裂石英组构与显微构造分析

西马坊断裂发育于芦芽山复背斜的倒转翼上,构成了宁武—静乐煤田的西部边界。断裂下盘下寒武统砂岩的石英组构显示B构造岩的特征,与Price7号岩组特征类似,反映其形成于褶曲翼部,为构造挤压的产物。该岩层中,石英的显微构造比较发育,主要表现为显微剪破裂与压扭性破裂。通过对石英岩组与显微构造分析,恢复了西马坊断裂活动的古应力场,并对断裂的形成机制进行了讨论。

Analyses on quartz fabric and microstructure of Ximafang fault

The Ximafang fault is located in the west boundary of the Ningwu-Jingle coal field, which lies on the overturned limb of the luyashan composite anticline. The quartz fabric of lower Cambrian sandstone in its foot wall is similar to the fabric of the Price 7, shows the feature of B tectonite, and indicats that it was formed in the fold limb caused by the tectonic pressure. There are many microstructures in quartz grains of the rock formation. Most of them show shenr joint or compresso-shear joint. Through the analyses of quartz fabric and microstructures, the paleostress field formed the fault is reappeared and the forming mechanism of the fault is discussed.