Zircon U-Pb geochronology and Lu-Hf isotope geochemistry constraints on Neoproterozoic S-type meta-granites from the Tutak area, Sanandaj-Sirjan Zone, Iran

Meta-granites in the Tutak metamorphic Complex (TMC) preserve crucial information about the Late Neo-proterozoic tectonic history of the Sanandaj-Sirjan Zone, Iran. This paper employs comprehensive zircon U-Pb geochronology, whole-rock geochemistry, and zircon Lu-Hf isotopic data to elucidate the protolith, tectonic setting, and evolutionary history of these rocks. Late Neoproterozoic zircon U-Pb ages of ca. 575 Ma are taken as the crystallization age for the protolith to the meta-granites, which are intruded by leucogranite with a zircon U-Pb age of 543 Ma. Zircon trace element data indicate that the grains have the late magmatic signature extracted from continental crust mafic zircons under oxidizing conditions. The meta-granites have a pronounced high-K-alkaline, peraluminous S-type signature. The meta-granites have zircon epsilon Hf(t) ranging from-4.2 to +2.3 and the TDMC model ages from 1.3 Ga to 1.7 Ga, suggesting the involvement of Paleoproterozoic crust. The geochemical data indicate that granitic melts in the Sanandaj-Sirjan Zone were produced via partial melting of lower crustal igneous crustal rocks (i.e., amphibolite) and sedimentary sources (i.e., metapelite). Based on the data (e.g., negative anomalies of Ba-Nb and enrichments of Rb-Th-Ce and U/Yb, Nb/Yb ratios in zircon), they have been formed in a post-collisional setting related to the convergence of peri-Gondwana terranes and Iranian continental fragments.