Study of origin and petrogenesis of granitoid bodies of Soursat complex (Northwest of Takab): Whole- rock ‎geochemical and Sr-Nd isotopic evidences

The plutonic bodies in the Soursat complex are parts of the widespread plutonic bodies in the Sanandaj- Sirjan zone. Based on field observations and microscopic studies, the study area is dominated by hornblende gabbro, quartz diorite, monzodiorite, granodiorite, monzogranite and tonalite. According to geochemical studies, the granitoids of Turke Dare and Khangholi are characterized by I-type nature, high K calc-alkaline, metaluminous composition and plotted on Volcanic Arc granite area (VAG) with 87Sr/86Sr(i) and εNd(t) values equal to 0.70448, -0.12. The overall geochemical signatures represent that monzodiorites generated from magma that derived from mantle which subjected to assimilation and contamination processes. The Pichaghci, Hamzeh Ghasem and the Northeast Khangholi bodies are I-type, metaluminous to peraluminous and calc-alkaline which are plotted in the volcanic arc granite area (VAG) with 87Sr/86Sr(i) and εNd(t) values equal to 0.70529, -2.82. These geochemical criteria indicate that the study granodiorites generated from mixing of mantle-derived magma with crustal melts. The Ghare zagh and Ouch dare monzogranite bodies are S-type, peraluminous and calc-alkaline which are plotted in continental- continental collision area with high values of 87Sr/86Sr (i) and εNd(t) equal to 0.94476, 0.879276 and -6.71, -6.61 representing that monzogranites originated from crustal melts. The Tonalite group is I-type, calc-alkaline, peraluminous, with low values of La/Yb, Sr/Y and Nb/Ta ratios and low fractionated patterns of rare earth elements (REE), negative anomaly of Eu. On the base of these data, it can be concluded that the group resulted from amphibolitic crust that generated from thickened mafic crust or under plate basalts under low pressures and low deep with the presence of plagioclase in the source area.