Chemical Composition and Genesis of Zeolitic Succession in Sartakht Area, SESemnan, North of Central Iran

Zeolitic succession in the Sartakht area is located 20 kilometer of SE-Semnan and north of Central Iran zone. Based on optical microscope and geochemical analysis, primitive rock is pyroclastic. On the basis of geochemical composition of rare earth element, primary tuffs were rhyodacite to dacite in composition. Volcanic glass fragments are the most important and suitable starting material, Owing to their high chemical reactivity, their bulk composition is similar to zeolites. The process of diagenesis was hydrolysis associated with the removal of SiO2, K2O, and Na2O from precursor materials and variable changes in CaO