Writers : Allahpourvand,Esmaeil;Vosoughi abedini,Mansoor;Karimpour,Mohammad Hasan;Emami,Mohammad Hashem
Refference : The 20th Symposium on Geoscience;Tehran
Publishing Year : 1380

Abstract :
The area is situated between 59 00 to 59 20 degrees in north birjand mountains. According to petrographic studies, extrusive Igneous rocks have a vast Composition form Dacite to rhyodacite. Andesitic- dacite, andesite and basitic andesite, that erupted during a Ma period from end of cretaceous to early neogen. Based on Tectonomagmatic diagrams and spiderdiagrams studies, geodynamic location of this volcanic complex has been explained. Results show that this compositions be related on orogenic mechanism and continental margine calcoalkaline lavas. Increase of Zr component in this extrusive igneous rocks in strong probability resulted from mixing of parent magma with relatively thick crust materials. Follow evidences, m and Ba l.a ratios. extraordinary distribution of pyroclastic components, considerable presence of amphibole phonocrysts, absence of linear relationship between Zr and TiO2 and exraordinary sufficiency of lithophyl elements with large ionic radiation, supported the results and reinforced the Idea of correlation between north birjand extrusive igneous rocks with active continental margines calcoalkaline lavas.
Subject List : Volcanism