Abstract
SHRIMP U–Pb dating of zircon from two representative samples of the Bardkish sye-nitic pluton, Urumieh plutonic complex, northwestern Iran, yielded a Late Cretaceous weighted mean206Pb/238U age of 91.1 ±0.8 Ma (Turonian). The pluton is character-ized by high K2O content, Ti–Nb–Ta depletion, enrichment in light rare earth elements and large ion lithophile elements compared to high field strength element, Mg-rich biotite and calcic amphibole, suggesting a shoshonitic affinity. Geochemical features of the Bardkish syenite are consistent with derivation by fractional crystallization of initial mafic parent magmas. It is most likely that primary magma of the sye-nite originated from a metasomatized subcontinental lithospheric mantle source with minor crustal component, and underwent a fractional crystallization process during its emplacement. The estimates of trapping pressures and temperatures suggest that crystallization began at the middle crustal level (less than 11 km) near 700–730°C. The generation of the Bardkish syenite could be related to the subduction of Neo-Tethyan oceanic crust beneath the Central Iranian microcontinent and it possibly marks a major magmatic episode prior to the final closure of the Neo-Tethyan ocean in northwest Iran.
Original language | English |
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Article number | e12375 |
Pages (from-to) | 1-21 |
Number of pages | 21 |
Journal | Island Arc |
Volume | 29 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1 Jan 2020 |