abandoned mines, Nízký Jeseník Mts., clayey shale, collapses

The hilly landscape of the Nízký Jeseník Mts. is interlaced with the tens of the underground clayey shale mines of the various age and length. Many of these mines have been quarried since 18th century and some of them are still in the operation. The largest mine works reach a few kilometres length and they are tens of meters deep. Some of them have been mined in two or three levels. The steeply inclined clayey shale flags were mined by the battery breast. Huge underground chambers and pillars remained after this method of the mining. Over the time when the mines are abandoned the chambers started to be unstable and the collapses of the walls and the ceilings destabilize the superficial terrain above the mine works. The paper discusses the current state of the mines and describes the most important collapsed localities.