Source and geothermobarometry of the gabbrodioritic intrusive body, (S- Qorveh - Kurdistan); with emphasis on minerals chemistry

Gabbrodioritic pluton is located in S-Qorveh in nourthern parts of the Sanandaj-Sirjan Zone. Petrographically, amphibole and plagioclase are main minerals in these rocks. Amphiboles are calcic-type, and their composition varied between ferro-hornblende to magnesio-hornblende. Anortite contents in plagioclases are between 81 to 39 (%) and these crystal are labradore -oligoclase in composition. According to coexist hornblende-plagioclase and Al in amphibole geothermometry methods, temperatures of crystallization are yielded ~723°C. In the later method, data indicates that the investigated rocks were emplaced at average pressure of 3.5 Kbar corresponding to a depth of ~12 Km. Oxygen fugacity was high in magma. Na2O content in amphibole and their calc-alkaline nature show gabbroic diorites are related to subduction setting. Mg#, Al2O3 and TiO2 contents in hornblende indicate mixing of crustal and mantle sources to generate magma of the Darvazeh gabbrodioritic magma. Variations in the composition of plagioclase may be related to H2O content in environment and the role of chemical variation due to input of crustal materials.