Origin of heavy rare earth elements in highly fractionated peraluminous granites

Rare earth elements (REEs + Y) play an important role in modern industry. Heavy REEs (HREEs) are particularly critical because of their relative scarcity nature. Global HREE resources predominantly present granitoid weathering crusts southern China. Although it is well known that generally enriched alkaline rocks, contrast, the parental granitoids most Chinese deposits peraluminous. Here, we examined different REE mineral compositions, distribution patterns, and Nd isotope ratios complex Zudong, South China, whose form largest globally. The composed granodiorite, biotite-muscovite, muscovite alkali-feldspar granites, patterns change from depletion to enrichment light (LREEs) with increasing negative Eu anomalies. They not fractional crystallization products same melts owing zircon U-Pb ages (?191, ?169, ?154 Ma for respectively). However, magmatic zircons three types show consistent initial Hf compositions [?Hf(t) = 3.4 8.6], indicating they evolved sources. granodiorite contains primary LREE minerals low ?Nd(t) values (?13.8 ?10.1), decoupled high isotopes. This indicates a garnet-containing basement source resulted Lu (HREE) remaining preferentially garnet phase, entering melt. contradicts concentration recorded biotite-muscovite which contain abundant associated muscovite, fluorite, recrystallized quartz. whole-rocks secondary variable higher [?Nd(t) ?3.7 2.9 ?11.4 ?7.1 respectively] than early granodiorites minerals, minimal 143Nd was derived radioactive decay 147Sm wall rocks. constrained contribution external REE-, volatile-rich liquids, drove segregation highly silicate magma chamber. increased volatile saturation fluid exsolution, may have mobilized HREEs metasomatized granites during emplacement. Therefore, infer metasomatism appears be crucial fractionated peraluminous granites.