The investigation of thermodynamic conditions in the formation of regional metamorphic rocks of the Tutak complex (southeast of Bavanat)

The Tutak metamorphic complex located in the southern part of the Sanandaj-Sirjan zone, is among the areas where the Paleozoic rocks are well exposed. This metamorphic complex mainly comprise of the Cambrian to the early Carboniferous marble, schist, amphibolite and genesis units. Garnet-biotite thermometric method and Garnet-biotite-muscovite barometric method carried out on dark schist from the Tutak metamorphic complex repersent 423 °C and 1.6 kb in the early stage of metamorphism to 708 °C and 5.9 kb during peak of metamorphism. These temperatures and pressures point to amphibolite facies conditions. The thermal cessation and also the marked difference in the degree of metamorphism between the Tutak complex and the late Carboniferous- early Permian succession in Surian, indicate that this phase of metamorphism probably occurred prior to the Late Carboniferous period.