Petrology and geochemistry of Aligoodarz granitoid, Western Iran: implications for petrogenetic relation with Boroujerd and Dehno granitoids

The Aligoodarz granitoid occurs in Sanandaj-Sirjan Zone (SSZ), Western Iran. Tonalite, granodiorite and granite are the main rock types cropping out in the area. Comparison of Aligoodarz granitoid with Dehno and Boroujerd granitoids reveals several similarities in their chemical characteristics. Thus, the above mentioned granitoids can be assigned as a co-genetic magmatic suite, in which plutons evolved from a parental magma; with fractional crystallization being the main mechanism for magma evolution. Samples with lower SiO2 content from different areas, are not similar in composition, and indicating varying degrees of mineral accumulation and trapped interstitial melts. These granitoids are compositionally similar to normal I-type granitoid rocks originated from continental arcs. Compared with the primordial mantle, they are enriched in Large Ion Lithophile Elements (LILE) and Light Rare Earth Elements (LREE) over High Field Strength Elements (HFSE) and Heavy Rare Earth Elements (HREE). This feature together with relative depletion of Ta, Nb, Ti, and P confirm derivation of these granitoids from a crustal source region in continental arc environment