Biotite application in characterization of tectonic setting of Malayer granitoieds

Abstract:
      Biotit is the dominant ferromagnesian mineral in granitic rocks. In recent years, in addition to whole rock analyses, analyzed biotites are used in granitoied petrogenezes study and the amount of iron, magnesium and aluminum of biotite in granitic rocks can be applied as indicator for determination of tectonic setting of granitoied.
   Granitoids are present in Malayer region in Sanandaj-Sirjan zone. Biotite is one of the main minerals of monsodiorites and syenodiorites. In this study biotites have been analyesd to investigate the origin and tectonic setting of the pluton.
   Point analyses of biotite indicate that monsodiorites and syenodiorites are peraluminous. Using the petrogenetic diagrams based on biotite analyses, intrusive rocks in Malayer region were formed from calc-alkaline S type magma with P type characteristics. P type rocks are formed in the collision area.