Geochemistry and tectonic setting of metapelites rocks in the Aligudarz area (Sanandaj-Sirjan Zone)

Metamorphic rocks are two groups of contact and regional in North West of Aligudarz. Regional metamorphic rocks in this area are composed from slate, phyllite, schists and contact metamorphic rocks are spotted schists and hornfels respectively. Petrographic studies of this rocks show that andalusite, cordierite and sillimanite minerals formed during of contact metamorphism. The geochemistry of theses rocks suggested that shale or greywacke is parent sedimentary rocks. The major and trace element show that igneous rocks (almost andesite) were primary rocks for these sediments. In comparison with average of upper continental crust, the rocks of studies area indicate of Rb, Sr, K negative anomalies cause to replacements of these elements during metamorphism and alteration. Discriminations diagrams of tectonic setting indicate a subduction zone (OIB). Based on the P-T pseudo sections and Bt-Sil- Cord, Bt-Sil and Sil-Cord paragenesis, for contact metamorphism estimated T and P were 650-670 ˚C and 3.5 Kbar respectively.