Lithium-zoning in hydrothermal zircons from Osayama jadeitite: A clue to understanding subduction-zone fluids

Abstract

Trace elements distributions of hydrothermal zircons (523 ± 1.8 Ma) from Osayama jadeitite were determined using a LA-ICPQMS. Zircon with ossilatory growth texture contains up to 30-70 μ/μg [Li], showing systematic element coupling with Y, Nb, U, Pb,Th, Ce and HREEs. [Li] doesn't correlate to Ti. Considering trace elements partitioning coefficients between zircon and hydrothermal fluid, a jadeitite-forming fluid in equilibrium with the hydrothermal zircon had very high [Li], which was at least one magnitude order higher than inferred subduction zone fluids in the literature.