Rapidly searching for carbonatite-related rare earth element (REE) mineralized systems is of paramount importance in exploration because these systems provide the world’s most significant supply of REEs. Biotite and barite are suitable indicator minerals that can offer reliable elemental geochemical information used for REE exploration. In this study, we provide an elemental geochemical dataset of biotite and barite from Cenozoic REE deposits in the eastern Tibetan Plateau, and compared the obtained data to those of biotite and barite forming in other geological settings. The fluorine (F) contents in carbonatite-hosted biotites are highly variable, with biotites from mineralized carbonatite complexes having much higher values (1.05 to 2.37 apfu, where apfu = atoms per formula unit) than their counterparts from barren carbonatite complexes (≤ 1 apfu). It is therefore believed that the presence of high-F biotites can be regarded as a sign for predicting REE reservoirs. Barites in REE mineralized systems contain much higher (even one or two orders of magnitude) total REE contents (ΣREE > 100 μg/g) relative to those species forming in carbonate-hosted fluorite-barite deposits and open marine environments. This means that high ΣREE concentration of barite can serve as an effective index for REE exploration. This information is integrated into a REE exploration program in which the areas with strong local tectonism along cratonic edges are priority exploration targets, and high-F biotites and REE-rich barites can serve as direct indices for rapidly identifying carbonatite-related REE mineralized systems at a strategic distance from other geological settings.
Full-text paper:
Mining, Metallurgy & Exploration (2023) 40:1253–1263, https://doi.org/10.1007/s42461-023-00792-4
