Geodynamic Development of Eurasian Active Margin at Pre-collision Subduction and at Post-collision Closing of Tethys Ocean

Geodynamic development of Eurasian Active Margin is related to Phanerozoic collision and closure of Tethys Ocean coincided with northvergent movement and stressing of Afro-Arabian continent at the Eurasian margin. The collision coincided with subduction oceanic Slab under margin of continent at pre-collision stage revealed in formation of island arc, inter-arc backarc and minor ocean settings at pre-collision stage. After closure of ocean the subduction is terminated and pre-collision stage transferred in post-collision and orogenesis, caused by stressing Afro-Arabian continent at the Eurasian. Character of subduction determined the settings of pre-collision stage. The island arc setting is related with steady state subduction, interarc-backarc and minor ocean settings are controlled by steepening of subducting slab which caused invasion of mantle diapir extension and spreading the crust revealed in rifting in interarc-backarc and intensive spreading in minor ocean setting, whereas at island arc setting the mantle invasion and spreading did not occur. So, scale of mantle material participation in various settings determined character of volcanism and tectonics. The island arcs are characterized by calc-alkaline rhyo-dacite-andesite-basalt volcanism blocking tectonics, revealed in island uplifting and gold-base metal mineralization. The interarc-backarc settings revealed in tholeiite-olivine basaltic volcanism, rifting and Zn-Cu mineralization the minor ocean setting controlled by ophiolite volcanism ultimatic dunite-peridotite-magmatism and the most intensive spreading of lithosphere and copper-pyrite mineralization confirmed by volcano-petrogenic, metallogenic and tectonic indications and geochemical cryteria. Therefore, type of volcanism, magmatism and mineralization at precollision development are controlled by scale and influence of crustal-mantle participation. The post-collision stage of geodynamic development also is characterized by various scales of crustal mantle influence. Our studied region consists of preand post-collision stages, located in Iran, Caucasus, Turkey and Balcan-Carpathian is parth of the Eurasian active margin. At post-collision, as at pre-collision stages the volcanic-magmatic activity, tectonics and mineralization are depended on the crustial-mantle scale of influence and are controlled by volcano-petrogenic, metallogenic, as well as, tectonical and geochemical indicators.