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oa Variations of Europium Anomaly Estimates in Lanthanide Spectra of Natural Monazite-Group Minerals
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 18th International Conference Monitoring of Geological Processes and Ecological Condition of the Environment, Apr 2025, Volume 2025, p.1 - 5
Abstract
This article presents the results of a study on the variability of European anomaly values in the lanthanide spectra of in natural monazite-group minerals of diverse genesis. The spectra of monazites-(Ce), monazites-(La), monazites-(Nd), monazites-(Sm), monazite-(Gd), and nodular monazites were used. The lowest value of the European anomaly Eu/Eu* 0.06 in the lanthanide spectrum was determined for monazite-(Sm,Nd,Ce) from the Blue Beryl Dyke of the Julianna pegmatite system, while the highest value, 9.05, was observed in the Ln spectrum of monazite-(La,Ce,Nd) from a samples of Archean banded iron-formation. These values differ by approximately 150 times. The greatest variation in Eu/Eu* 6.64 (2.41–9.05) is characteristic of monazite-(La,Ce,Nd), whereas the smallest variation is observed for monazite-(Sm,Nd,Ce) – 0.05 (0.06–0.11) and monazite-(Gd,Sm,Nd) – 0.05 (0.19–0.24). The variation in European anomaly values Eu/Eu* for monazite-(Ce,Nd,Sm) is 0.01 (0.35–0.36), and for monazite-(Nd,Ce,Sm) it is 1.25 (0.43–1.68). The variation in European anomaly values Eu/Eu* for monazite-(Ce,La,Nd) is 2.23 (0.11–2.34) and for monazite-(Ce,Nd,La) it is 2.16 (0.11–2.27), showing similar patterns. The high variability of European anomaly values Eu/Eu* in the studied lanthanide spectras is a result of lanthanide fractionation during mineral-forming processes. Extreme variations are particularly characteristic of rare samples of monazite-(La,Ce,Nd) lanthanide spectra and monazite-(Sm,Nd,Ce) lanthanide spectra.