Based on the lithology, thickness of aquifuge and changes of the rock between Ordovician limestone aquiferous to lower-group coal seam, the watertightness of aquifuge are evaluated.

• 对矿区内奥灰含水层与下组煤之间隔水层的岩性、厚度及变化进行了分析，并对隔水层的隔水性能做出了综合评价；