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The protected area 'Bohemian Switzerland National Park' with its characteristic sandstone landscape was influenced by the long-term air pollution and acidic deposition within the area known as Black Triangle (located where Germany, Poland, and the Czech Republic meet, is one of the Europe's most polluted areas). The local Upper Cretaceous sandstone is subhorizontally stratified, fine- to coarse-grained, quartz dominated, with low content of clay minerals. One of the significant negative effects of the intensive acidic deposition on sandstone outcrops has been identified as chemical (salt) weathering, i.e., a process when the porous sandstone rock is except of chemical influence attacked also by force of crystallization of growing salts crystals. Anions NO together with SO and cation NH were the most abundant solutes in bulk precipitation samples. Current (2002 to 2009) bulk deposition fluxes of SO determined at three sites directly in the National Park indicate decline from 23 to 16 kg ha year. Infiltration of bulk precipitation solutes into the sandstone mediates the weathering processes. Natural outflow of sandstone pore-water (sandstone percolates) can be sampled only during certain days of year when the sandstone becomes saturated with water and percolates drip out on small number of sites from roofs of overhangs. Under usual conditions percolation water evaporates at the sandstone surface producing salt efflorescences-the typical example is Pravčická brána Arch locality. The average pH of the dripping sandstone percolates was 3.76. Concentration of SO and Al in sandstone percolates reached up to 46 and 10 mg L. The concentration of Al in percolates has been 160-fold greater the one in the precipitation samples suggesting the sandstone as a source. The water O and H isotopic composition of percolates has been virtually identical to precipitation samples, indicating thus relatively short residence time of the solutions within the sandstone pore-spaces. Evaporation experiments with bulk precipitation and percolate samples proved possible origin of some Ca in bulk precipitation and the sandstone rock as the source of Al and possibly of K for the salt efflorescence identified on Rock Arch body. [ABSTRACT FROM AUTHOR]

Concentration of sulphate, δ34S(SO4 2−), δ18O(SO4 2−O) values, in surface waters and groundwaters from crystalline rocks in mountainous Rudawy Janowickie Massif (RJ) in SW Poland, have been analysed. The RJ is located close to the area of the biggest anthropogenic emission source of sulphur compounds in Europe called the “Black Triangle”. The lowest concentration of sulphate ions dissolved in water (13 mg/l) were found in groundwaters at the highest altitude (750m asl). In the course of groundwater downward infiltration (hydraulic gradient) the concentration of sulphate ions increased with decreasing altitude. The highest concentrations of SO18O(H2O) values, in surface waters and groundwaters from crystalline rocks in mountainous Rudawy Janowickie Massif (RJ) in SW Poland, have been analysed. The RJ is located close to the area of the biggest anthropogenic emission source of sulphur compounds in Europe called the “Black Triangle”. The lowest concentration of sulphate ions dissolved in water (13 mg/l) were found in groundwaters at the highest altitude (750m asl). In the course of groundwater downward infiltration (hydraulic gradient) the concentration of sulphate ions increased with decreasing altitude. The highest concentrations of SO4 2− (100 mg/l in springs at metamorphic rocks and 60 mg/l in springs at granites) were observed at the foothills (altitudes 410 and 580 m asl, respectively). Likewise, the sulphur and oxygen isotope composition of sulphate ions showed systematic increasing trends with respect to the altitude decrease (from 3.45 to 11.05‰ and from −6.53 to 10.03‰, respectively). Three main sources of sulphate for the surface-water/groundwater systems in RJ have been isotopically discriminated. The high δ34S-δ18O sulphate showed waters from precipitation and peat bogs. The lower δ34S–δ18O sulphate originated due to decomposition of organic matter. The lowest δ34S–δ18O sulphates formed due to microbial ( Thiobacillus ferrooxidans) pyrite oxidation within the pyrite-deposit weathering zone. The highest contribution of anthropogenic sulphate have been observed at the top-hills and during low water levels at lower altitudes. The contribution of biogenic and geogenic sulphate relatively increased with the increasing distance (time?) of the water flow through rocks or/and increasing water level in springs. The isotope, hydrochemical and hydrogeological observations confirmed a negligible role of anthropogenic sulphur in the groundwaters analysed. This suggests significant improvement in the natural environment in the Western parts of Sudety Mountains. [ABSTRACT FROM AUTHOR]

The isotope composition of sulphur and oxygen were measured in water collected from the Central Roztocze (SE of Poland) rivers. The research focused mainly on the upper section of the Wieprz River, its confluences and springs and on two confluences of the Tanew River. The results proved that there are two sources of sulphate dissolved in water: the Cretaceous aquifer and soil within the catchment's area. Seasonal variation of the sulphate concentration together with sulphur and oxygen isotope composition was observed. The isotope composition of sulphate varied in water collected at the different locations of the same river. They are similar for sulphates in springs and rivers. The isotope composition of sulphate varied in water collected at the different locations of the same river. The δ34S values of sulphates in the Wieprz River are the lowest (negative) in lower part of the river. It shows that the contribution of sulphate from spring water increases downstream. The low sulphate content and high δ34S and δ18O value in sulphates was found downstream from dams. It may be the result of deficiency of oxygen in mud and the reduction in bacteria activity. The seasonal variations of the oxygen isotope composition in sulphate are significant in sulphates collected from rivers and from springs. They are caused by seasonal variations of the δ18O in water stored in the soil. The narrow range of the δ18O values for the sulphates extracted from springs at the same time means that the main source of sulphate in spring water are oxidising processes using the same source of oxygen in every location. The high sulphate content combined with the high δ34S values of the sulphates in springs suggest, that the sulphates from Cretaceous aquifer were mixed with sulphates dissolved from the soil. [ABSTRACT FROM AUTHOR]