Magmatic zircons from I-, S- and A-type granitoids in Tibet: Trace element characteristics and their application to detrital zircon provenance study

Abstract

This study reports a dataset of 21 trace elements of magmatic zircons from typical I-type (93 analyses) and S-type (73 analyses) granitoids from the Lhasa and Himalayan terranes, southern Tibet, and A-type granitoids (21 analyses) from the Songpan–Ganzi terrane, eastern Tibet. Our results indicate that magmatic zircons from the I-type granitoids are characterized by relatively lower Pb concentrations and higher (Nb/Pb)N ratios, distinct from those of the S-type granitoids that reveal higher Pb, lower (Nb/Pb)N and significant Eu negative anomalies (Eu/Eu*⩽0.3); while these values are transitional in zircons from the A-type granitoids. Such differences, most likely governed by compositional variations in the host magmas, are considered as a useful tool, in addition to U–Pb and Hf isotopes, for tracing the source provenance of detrital zircons. Consequently, the trace element compositions of detrital zircons with a diagnostic age peak (∼1170Ma) from the Lhasa Terrane indicate the presence of coeval S-type magmatism in their source region. This study exemplifies the usefulness of zircon trace element geochemistry in investigating sedimentary source provenance and paleogeographic reconstruction.