Geochemistry and petrogenesis of Adakitic rocks from the Kiyamaki magmatic dome, southeast Jolfa (NW Iran)

Composition of the Kiyamaki dome has mostly dacite and granodiorite in rims, with SiO2 contents ranging from 64 to 73 wt% and Mg# values ranging from 27 to 57. These rocks are high-Si adakite. Geochemical characteristics and Sr and Nd isotopic rates indicate that the rocks of Kiyamaki dome are a post-collisional adakite. Combined geochemical and Sr–Nd isotope data suggest that the Kiyamaki adakitic magma derived from partial melting of mafic rocks in the lower part of a thickened crust. So, with attention to tectonic setting and source of derived adakitic magma, age of Eocene to Miocene for generation and closing time of Neo-Tethys (Middle Miocene), it is not possible that generation of Kiyamaki adakites be directly related to geodynamical evolution of Neo-Tethys. Here, with suppose of age information for generation of Kiyamaki dome and closing of Neo-Tethys,formation of domes in the northern part of Tabriz fault can be related to the collision of Sanandaj-Sirjan micro-continual with Alborz-Azarbaijan block in Paleogene that was happened due to subduction of oceanic crust of Khoy-Zanjan basin toward beneath of Alborz-Azarbaijan block.