Geology studies and petrogenesis of the volcanites of Marand southwest

Category Petrology
Group GSI.IR
Location 20th symposium on geosciences
Holding Date 16 April 2008

     ‍‍‍‍‍‍The studied area is located in northest of IRAN ,20 Km northwest of MARAND. Volcanic activity ol the area appears as lava flows. dykes. tuffs. pyroclastics and are erupted during several stages. based on field geological studies. This volcanic rocks are plotted in phonolitic tephrite. Mugearilc. Hawaiite. Trachyandesite and dacite in TAS diagram.They are also undersuturated From silica and high—k in character, therfore this volcanic rocks shows potassic alkaline rocks character. Major elements geochemical studies shows that cristallization of clino pyroxen. olivine, leucite and plagioclase were main process in magmatic diffrentiation. High content of LILE, LREE in addition to low contents of HFSE indicates crustal contamination and metasomatism oF mantle source of the magma. Crustal tickining due to EUROSIAN and ARABIAN plates collision, tends to increas thermal gradient, Which in turn tends to fractional melting of the mantle beneath the collision area.The produced magma raised through the local fracture speeialy effect of TAI3RIZ fault and then erupted to
the surlice.