ULTRAFILTRACJA I DIAGENEZA JAKO WAŻNE PROCESY FORMUJĄCE SKŁAD IZOTOPOWY I CHEMICZNY WODY W NIEKTÓRYCH BASENACH SEDYMENTACYJNYCH

Abstract

ULTRAFILTRATION AND DIAGENESIS AS IMPORTANT PROCESSES CREATING ISOTOPE AND CHEMICAL COMPOSITION OF WATER IN SOME SEDIMENTARY BASINS

Abstract. Saline waters in the Polish Flysch Carpathians can be regarded as representative for basins with clay sediments. They are preserved in deep tectonic traps, but due to geostatic overpressure they may travel to the surface along some fault zones and discharge in springs or be extracted by shallow wells. In some cases they mix with local meteoric water. The typical end member is characterized by δ¹⁸O≈6–7.5‰ and δ²H≈–25–30‰, with the molar Na⁺ to Cl^- ratio usually significantly exceeding 0.87. The isotope data indicate the diagenetic origin of water molecules released in illitization of clay minerals during burial diagenesis of flysch formations. The process is characterized by the dominant presence of Na+ in pore water. Saline waters of the bedrock are of marine origin in the Badenian strata and of paleoinfiltration origin in older formations.