High-temperature uranium mineralization in the Jiling Na-metasomatism uranium deposit, northwest China: Evidence from the isotope and element of rutile and apatite

• High Temperature U mineralized was identified in the Jiling deposit. • REE of hydrothermal rutile inherited from its precursor minerals. • Rutile is robust indicators for tracing characteristics of ore-forming fluids. The Jiling uranium deposit in Northwest China, which was previously considered a low-temperature system, presents evidence of high-temperature mineralization at depth. Petrographic analysis, elemental composition, and U–Pb dating of syn -ore hydrothermal rutile and apatite from this deposit were investigated in this study. Three distinct rutile types, each of which formed from a different precursor mineral, were identified: Rt-1 from altered Ti-rich magnetite, Rt-2 from ilmenite, and Rt-3 from biotite. These hydrothermal rutile types are contemporaneous with uraninite and apatite in the deposit. The three rutile types exhibit distinct rare earth element (REE) patterns. Rt-1 has a low REE content with light rare earth element (LREE) enrichment, and Rt-2 has a high REE content with a flat pattern. In contrast, Rt-3 shows an LREE-enriched pattern. These variations suggest that the REE signature of each rutile type is inherited from its precursor minerals. Furthermore, all three rutile types are enriched in high-field-strength elements (HFSEs). This enrichment was likely driven by the high-temperature, halogen- and CO 2 -bearing magmatic fluids responsible for their formation. In situ U–Pb isotope dating of hydrothermal rutile and apatite yields weighted mean ages of 432 ± 6 Ma and 435 ± 3 Ma, respectively. This study demonstrates that rutile and apatite can be used as robust tool for tracing uranium mineralization.