The occurrence and distribution of rare earth elements in mineral and thermal waters in the Polish Lowlands

• Published in: Journal of geochemical exploration 2022-06, Vol.237, p.106984, Article 106984
• Main Authors: Kaczor-Kurzawa, Dorota, Wysocka, Irena, Porowski, Adam, Drzewicz, Przemysław, Vassileva, Emilia
• Format: Article
• Language: English
• Subjects: Brine; Geothermal water; Groundwater origin; Poland; REE-fractionation; Saline water; Water-rock interaction
• ISSN: 0375-6742; 1879-1689
• DOI: 10.1016/j.gexplo.2022.106984

The occurrence and distribution of rare earth elements (REEs) in mineral and thermal waters encountered in Quaternary, Mesozoic and Permian aquifers of the Polish Lowlands are described, with REE concentrations analyzed in 35 groundwater samples and 25 aquifer host rock samples. The waters analyzed are characterized by high variability of total dissolved solids (TDS: 0.44 to 340 g/L) and of outflow temperatures (9 to 89 °C). Values of ultralow concentrations (pg/L-μg/L) of REEs in groundwaters of variable salinity were obtained using a novel method combining a seaFAST-pico preconcentration system with inductively coupled plasma mass spectrometry (ICP-MS). Very low concentrations of dissolved ( 60 °C) favouring a release of the more easily soluble MREEs from rocks into the water, (ii) the presence of organic material showing a strong ability to form complexes with REEs, (iii) reductive release (dissolution) of previously adsorbed REEs on mineral particles, and (iv) dissolution of rocks by acidic waters. Our findings confirmed that REEs can be a useful markers for identifying basic hydrogeochemical processes shaping the chemistry of waters. •REE contents and three REE-pattern types were determined in waters studied.•Combination of seaFAST system and ICP-MS detection for REE analyses in waters•REE-patterns in water and aquifer host rocks were used to assess REE-fraction