Petrography, Geochemistry and Tectonomagmatic Setting of the intrusive bodies of Jasb area

The Jasb area is located about 100 Km of South of Qom in Urmiyeh-Dokhtar magmatic belt. The scattered plutonic rocks belong to Eocene-Oligocene and Miocene. The plutonic rocks’ type Variations are granite, quartzmonzonite, tonalite-granodiorite, quartzmicrodiorite, and gabbrodiorite. The petrographic studies revealed that the textures of plutonic rocks are mainly granular and sometimes graphic or porphyritic. The magmatic series of intrusive rocks except gabbrodiorite types (toleitic) are calk alkaline and metaaluminums. Probably, the small massive granite rocks in the investigation area are I - type granite. The Rocks in this area compositionally belong to the tectonical regime of the VAG and SynCOLG. Considering change in abundance of minerals such as pyroxene, magnetite, amphibole, biotite, plagioclase and feldspar in the intrusive rocks, hence, it is indicative of successive process of differentiation in intermediate magma, and ultimately creatingvariation in lithology. According to the analysis results, the geochemical diagrams were drawn and interpreted. Defining the lithology of intrusives, the tectonomagmatic condition, magmatic series, andgeochemical variations are the results of geochemical and petrologic studies of intrusives in the area.