宇部鉱業所における坑内水について

抄録

The Ube coal mine is developing the submarine coal seams belonging to the Tertiary formations. The coal field is divided into two areas by the Tsubuta fault, which runs nearly parallel to the shoreline under the sea bottom.
The underground water in the inside area which is cut by the Tsubuta fault, i. e. the area adjoining to the land is sea water type, which the water in the outside area is special type rich in HCO₃.
The highly-pressed water flowing in the stratum above the coal seam somtimes breaks the roof of the working-face, which is protected by the draining bore-hole.