The complex hydrogeology of the unique Wieliczka salt mine

Abstract

A b s t r a c t. The salt mine in Wieliczka is a mining plant which is unique on the worldwide scale, which has been developing since the Middle Ages until the present times. The high geological complexity of bedrock in the vicinity of the mine, which is associated with the Carpathians orogeny, determines the high level of complexity of local hydrogeological conditions. At present, about 260 l/min of water discharges into the mine, which is considered very high as for a salt mine. 86% of that amount comes from three major inflows, i.e. WVII-16 (from Fornalska II chamber), WVI-32 (from Z-32 chamber) and WVI-6 (from Z-28 chamber). These seepages cause threats to the mine, not only due to their large volumes but also due to high quantities of salt that is leaching from the rock mass. The most troubled area in the Wieliczka salt mine, from the hydrogeological viewpoint, is the northern border, where salt deposits are in contact with strongly dislocated sandstones via a gypsum-clay layer. These sandstone deposits comprise not very productive aquifers that, to some degree, are isolated from one another.