Origin of unusual HREE-Mo-rich carbonatites in the Qinling orogen, China.

ABSTRACT: Carbonatites, usually occurring within intra-continental rift-related settings, have strong light rare earth element (LREE) enrichment; they rarely contain economic heavy REE (HREE). Here, we report the identification of Late Triassic HREE-Mo-rich carbonatites in the northernmost Qinling orogen. The rocks contain abundant primary HREE minerals and molybdenite. Calcite-hosted fluid inclusions, inferred to represent a magmatic-derived aqueous fluid phase, contain significant concentrations of Mo (~17 ppm), reinforcing the inference that these carbonatitic magmas had high Mo concentrations. By contrast, Late Triassic carbonatites in southernmost Qinling have economic LREE concentrations, but are depleted in HREE and Mo. Both of these carbonatite types have low δ²⁶Mg values (-1.89 t

SUBMITTER: Song W 

PROVIDER: S-EPMC5114661 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature