Petrology, Geochemistry and Mineralogy of potassic and ultrapotassic (Mainly shoshonitic) lavas in NW of Marand (Azarbaijan)

Volcanic rocks of NW Marand Ageing Plio-Quaternar consist of andesite, Basaltic andesite, leucite tephrite, leucite basanite and tephrite. High concentration of K2O and MgO and also the ratio of K2O/Na2O indicate that volcanic rocks of this area could be classified as potassic and ultra-potassic, whereas they are shoshonite from magmatic series point of view. The study of minor elements shows that the rocks of the area are rich in of LILE and depleted of HFSE, indicating that lehrzolitic-garnet metasomatised mantle part of the lithosphere and high fugasity ratio of CO2/H2O play a crucial rule on the genesis of these rocks. Also contamination of part of the responsible magma with crustal material resulted in the change of magma chemical compotion from alkaline to sub-alkaline.