The potential for REEs in igneous-related apatite deposits in Europe

Abstract

Phosphate rocks and the Rare Earth Elements (REE) as potential by-products are listed as Critical Raw Materials (CRMs) by the European Commission. In Europe, igneous-related phosphate deposits are associated with carbonatites, alkaline complexes, (ultra)mafic intrusions, iron oxide apatite - iron oxide copper gold mineralisation, granites or formed in a metasomatic/hydrothermal context. To provide an overview of these deposits and assess their potential in CRMs, a database gathering in-situ analyses of apatite was compiled. The data emphasize the significant REE enrichment of apatite related to alkaline complexes and carbonatites. They also guide the use of apatite in mineral exploration, based on distinct geochemical characteristics. Among the latter are the Sr, Mn, total REE and Y contents of apatite, the degree of light and middle REE enrichment, the Eu anomaly, and the tetrad effect. Additional bulk rock analyses combined with estimates of reserves/resources of the deposits indicate a sub-economic potential of REE to be exploited as by-products of phosphate mining at Kodal, Bjerkreim-Sokndal and in the Northern Norrbotten district (Sweden). This study helps in identifying new deposits/areas of interest for CRMs exploration in Europe that could contribute to decrease the supply risk in these raw materials, through domestic production.Supplementary material at https://doi.org/10.6084/m9.figshare.c.5913009

Processes controlling rare earth element distribution in sedimentary apatite: Insights from spectroscopy, in situ geochemistry and O and Sr isotope composition

“…This would be the most efficient way to form large and economically interesting sedimentary phosphate deposits (Föllmi, 1996: Pufahl & Groat, 2017). This is clearly the case for the phosphatic calcarenite of the Mons Basin, which is one of the largest sedimentary phosphorite formations occurring in Europe, representing about 47 Mt of P 2 O 5 (Robaszynski & Martin, 1988) with an estimate of ca 0.4 Mt of REE oxides (Jacquemin, 2020; Decrée et al ., 2022a,b).…”

“…Jarvis, 1994; Trappe, 2001), they have so far been scarcely used, whether for igneous or on sedimentary apatite (e.g. Emo et al ., 2018; Li et al ., 2018; Yang et al ., 2018; Decrée et al ., 2020a, 2022a,b, for Sr isotopic composition; and Žigaitė & Whitehouse, 2014; Chen et al ., 2016; Sun et al ., 2016; Zeng et al ., 2016; Wotte et al ., 2019; Yang et al ., 2020; Decrée et al ., 2020a; Edwards et al ., 2022, for O isotopic composition). By combining high spatial resolution trace element, O and Sr isotopic analyses, the processes involved in apatite formation (and the changes regarding its mineralogy and chemistry related to later processes) were investigated with unmatched precision.…”

Leveraging Domain Expertise in Machine Learning for Critical Metal Prospecting in the Oslo Rift: A Case Study for Fe-Ti-P-Rare Earth Element Mineralization

“…The Kodal deposit represents the largest known occurrence of Fe-Ti-P-REE mineralization in the LPC, with total indicated resources of 14.6 Mt at 5.18% P 2 O 5 and 24.12% Fe [7]. Moreover, apatite from the deposit hosts between 0.92 to 1.29 wt.% total rare earth oxide potential by-products [4]. The western part of the deposit is exposed, where massive titanomagnetite-apatite-ilmenite-rich rocks (main mineralization) can be observed.…”

“…The ore varies from a few centimeter intervals that occur as pockets within the monzonite, displaying sharp contacts, to zones with approximately 2 m of thickness, normally surrounded by disseminated intervals (Figure 2a The Kodal deposit represents the largest known occurrence of Fe-Ti-P-REE mineralization in the LPC, with total indicated resources of 14.6 Mt at 5.18% P2O5 and 24.12% Fe [7]. Moreover, apatite from the deposit hosts between 0.92 to 1.29 wt.% total rare earth oxide potential by-products [4]. The western part of the deposit is exposed, where massive titanomagnetite-apatite-ilmenite-rich rocks (main mineralization) can be observed.…”

“…In this context, the geological setting of Norway displays great potential for the discovery and subsequent exploitation of critical raw materials, especially P-REE resources [4]. Notably, significant Fe-Ti-P-REE resources have been identified in Norway that are related to layered intrusions and alkaline intrusive complexes [5,6], emphasizing the potential for discoveries in diverse settings.…”