Warunki hydrogeologiczne i przewidywane zawodnienie kopalń w Lubelskim Zagłębiu Węglowym

Abstract

HYDROGEOLOGICAL CONDITIONS AND INFERRED WATER INFLOW TO MINES IN THE LUBLIN COAL BASIN Summary Taking into account the condttions of water supply to coal-bearing Carboniferous, two hydrogeological regions were differentiated in the Lublin Coal Basin (Fig. 1). The Central and Northern Coal Fields, at present covered by hydrogeological surveys, are situated in central parts of the second hydrogeological region (Fig. 1). In the hydrogeological profile of the Coal Fields occur 4 main water-bearing stages: Quaternary, Cretaceous, Jurassic and Carboniferous (Figs. 2-3). The Quaternary aquifers are connected mainly with sandy deposits. Limestone-marly Upper Cretaceous deposits display distinct stratification of permeability and water-bearing capacity, depending on fissurity and lithology of rock massif. Top parts of the Upper Cretaceous are characterized by increased permeability usually down to about 120 m. Sandy, conglomeratic Lower Cretaceous deposits, usually a few meters in thickness, are characterized by quite good permeability and water-bearing capacity. They carry water under pressure and are characterized by quick-sand properties. Jurassic deposits developed as limestones, dolomites and sandstones, are characterized by differentiation in lithology, fissurity and degree of karstification. They conduct waters under pressure of about 69 atm. The water-bearing capacity of coal-beraring Carboniferous is connected with sandstone and siltstone intercalations which form independent layer-fissure aquifers with water under pressure of 59-112 atm. Taking into account the hydrogeological model. of this area it may be stated that coal mining planned at depths from 650 to 1000 m will be carried out in zone of impeded circulation of water with mineralization up to 4.3 g/l. Aquifers of Westphalian deposits series are supplied by waters from Jurassic stage. Water will come to mining works at the expense of dynamic resources of elastic and static Carboniferous and Jurassic aquifers. Water inflow should not exceed 10 m3/min. Water hazard for future exploitation will be mainly related to the complex of Jurassic and Lower Cretaceous rocks directly overlying the deposit series. Mining works will result in change of hydrogeological and hydrographic relations in central area of the Lublin Coal Basin.