Multi-method geochronology and isotope geochemistry of carbonatites in the Aileron Province, central Australia

Abstract Carbonatites are complex rocks yet globally significant hosts of critical mineral resources. Mitigating exploration risk demands robust understanding of their geodynamic setting, which hinges on constraining the timing, duration and nature of associated magmatic and fluid–rock processes. We present multi-method geochronology and isotope geochemistry for the recently discovered Luni and Crean mineralized (Nb, REE, P) carbonatites of the Aileron Province, central Australia. We integrate data from multiple mineral-isotope-pairs: U–Pb and Lu–Hf in zircon, Rb–Sr in biotite and Sr, Lu–Hf, Sm–Nd and (U–Th)/He in apatite. Combined petrological and isotopic evidence resolves distinct geological events over >500 Myr. Zircon U–Pb and biotite Rb–Sr dates range from 831 ± 3 Ma to 796 ± 9 Ma. The oldest dates from less altered minerals reflect primary crystallization, and younger dates relate to pervasive hydrothermal alteration. Radiogenic isotopes (Sr–Nd–Hf) imply a moderately depleted mantle source with negligible recycled sedimentary components in the primary carbonatite magma. Our findings correlate carbonatite magmatism in the Aileron Province at ∼830–820 Ma with the onset of Rodinia Supercontinent breakup, during widespread rift-related extension and mantle-derived magmatism across Australia. Post-emplacement, Lu–Hf apatite dates from 722 ± 17 Ma to 653 ± 22 Ma suggest protracted alteration, whereas apatite (U–Th)/He data indicate exhumation at ∼250 Ma. Carbonatite emplacement probably exploited pre-existing transcrustal corridors during Tonian extension. These zones of structural weakness likely facilitated ascent of volatile-rich, mantle-derived melts to mid–shallow crustal depths, highlighting how regional geodynamics govern the localization and preservation of mineralized carbonatites.