Content of rare earth elements in basalt aggregate from Winna Góra, Poland

摘要

Seek for new Rare Earth Elements (REE) sources encourage looking for easily available sources located in Europe. REE in evolved magmatic systems are predominantly associated with alkali environments. Therefore, it was decided to identify the content of REE in alkali igneous rocks of the Winna Góra basalt quarry located in Lower Silesia, Poland. In this study, a commercially available basalt aggregate from Winna Góra deposit located in the south-western part of Poland near Jawornik was examined for REE content. Mineral content and chemical composition were examined with a light microscope, XRD and XRF, whereas trace element content was measured with the ICP-MS technique. A new method of sample preparation for the purpose of REE identification in basalt aggregate based on pressure microwave mineralisation was developed. Mineral composition and TAS diagram classify aggregate as tephrite. The mineral composition of samples reflects typical mafic and ultramafic rocks. Quantitative mineralogical analysis by the Rietveld method showed that the main minerals are anorthite (46.7%) and augite (37.4%) with a minor content of forsterite (7.5%), nepheline (7.4%) and apatite below 1%. The total content of REE does not exceed 132 ppm. Chondrite normalised curves show the highest concentration of La and Pr. In the case of HREE, the majority of elements (Eu, Tb, Dy, Ho, Er, Yb) concentrations were below 1 ppm, a Tm and Lu were not detected. The low enrichment in HREE was also reflected in La/Gd ratios. Obtained results are comparable to the REE contents in the western part of the Cenozoic European Volcanic Province.