Geochemistry and tectonic setting of Arghun intrusion, southwest of Mahneshan and comparing it with the neighboring intrusions

The Arghun intrusion is located in the southwest of Mahneshan and has penetrated in the Precambrian metamorphic rocks. The study area is part of the Central Iran zone. Lithologically, the main composition of this intrusion is gabbro and it has the mineralogical composition of plagioclase, pyroxene, hornblende and opaque minerals. Based on the geochemical composition, the magmatic nature of the study rocks is calc-alkaline. Their normalized REE pattern to the chondrite shows the enrichment of LREEs relative to HREEs. The negative anomalies of the Nb and Ti elements are observed in the spider diagrams normalized to the chondrite, which is characteristic of the subduction zone magmatism (active continental margin arc and island arc magmas). Also, LILEs enrichment and depletion of HFSEs elements indicate subduction arc magmas. The tectonic setting discriminant diagrams also show the characteristics of the island arcs and the active continental margin. Also, the study of the spider diagrams shows the involvement of subduction fluids in the formation of the study rocks. Comparison of the study gabbro intrusion with the north of the Takht-e-Soleiman intrusion and Aghdareh granite indicates that the magmatic series are the same and their spider diagram pattern are similar.