Zircon U–Pb ages and geochemistry of granitoid from the southwest part of the Taşlıçay batholith: Implications for Neotethyan closure in Eastern Anatolia, Turkey

Abstract

The composite Taslicay batholith that is located in the Eastern Anatolian Accretionary Complex (EAAC) includes I- and S-type granitoid rocks. This batholith occurred as a result of the collision between Arabian and Eurasian plates along the Bitlis–Zagros suture zone during the Early Miocene (Burdigalian). This paper presents new whole rock geochemical and zircon U–Pb geochronological data from the southwest part of Taslicay batholith. The study area contains S-type granitoids such as tonalite, granodiorite, monzogranite, and granite. These rocks are characterized by enrichments in large ion lithophile elements (LILEs) (Cs, Ba, Rb, K) and light rare earth elements (LREEs), and depletions in high field strength elements (HFSEs) (Nb, P, Ti). They contain a number of mafic microgranular enclaves (MMEs) that are quartz microdiorite in composition. Aluminium Saturation Index (ASI) and CIPW normative corundum values of these granitoids vary between 0.98 and 1.22 and 0.06–1.55%, respectively. The zircon U–Pb ages of the studied granitoids range between 19.8 and 20.0 Ma. Considering all geological, geochemical and geochronological data, we suggest that S-type granitoids from the southwest part of Taslicay batholith were formed with assimilation fractional crystallization (AFC) from a hybrid magma source in a syn-collisional (Arabian–Eurasian collision) tectonic environment.