SOLANKI GÓRNOŚLĄSKIEGO ZAGŁĘBIA WĘGLOWEGO

Abstract

BRINES IN THE UPPER SILESIAN COAL BASIN

Abstract. The Upper Silesian Coal Basin (USCB), 7,500 sq km in area (including 5,500 sq km in Poland) lies in the Silesian Variscan intermontane depression. Within this sedimentary basin the thickness of sediments reaches about 11 km. The multiaquifer formations have been identified in the hydrogeological section of the Silesian depression. It is observed a distinct hydrodynamic and hydrochemical zoning in the USCB. Hydrogeological environment of brines occurring in the Tertiary, and Upper and Lower Palaeozoic formations has been documented by results of chemical, gaseous and isotopic investigations of groundwater until the depth of 3,000 m. These brines of TDS up to 372 g/dm³ occur in different hydrogeological environments. They have some hydrochemical features characteristic for brines occurring in deep sedimentary basins. They are burried groundwaters transformed in process of hydrogeological environment diagenesis. Brines occur in range of regional flow system. There is observed a general trend of groundwater mineralization increase with depth, regardless of the stragraphic sequence. This general trend is disturbed by phenomena of hydrochemical anomalies. According to isotopic investigations brines are of different origin. Brines occurring in clayey Tertiary complex are synsedimentary waters. Brines occurring in Carboniferous, Devonian and Cambrian formations are palaeoinfiltration groundwaters of different ages as well as mixed groundwaters. Natural brines occurring in the depth interval up to 650-1100 m are being transformed by mining activity.