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

Abstract

Phosphate rocks and rare earth elements (REEs) 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 (IOA) and iron oxide–copper– gold (IOCG) mineralization, and granites or are 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 charac-teristics. 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 REEs to be exploited as by-products of phosphate mining at Kodal, Bjerkreim–Sokndal and in the northern Norrbotten district (Sweden). This study helps to identify new deposits/areas of interest for CRM exploration in Europe that could contribute to decreasing the supply risk for these raw materials through domestic production.