Geochemistry of the middle miocene collision-related Yamadaǧı (Eastern Anatolia) calc-alkaline volcanics, Turkey

Abstract

Major, trace element and K-Ar age determinations are reported for a suite from the Yamadaǧi{dotless} volcanics in the Eastern Anatolia. The exposed rocks mainly consist of medium-potassium calc-alkaline basaltic andesites, andesites and dacites. Petrographical data exhibit disequilibrium mineral textures, such as resorption of the ferromagnesian phases, clinopyroxene-mantled orthopyroxene, and sieve-textured plagioclases. The Yamadaǧi{dotless} volcanics have a calk-alkaline character, and trace element characteristics exhibit that the volcanics resemble subduction zone volcanics and/or volcanics assimilated by continental crust. K/Ar age determinations show that the Yamadaǧi{dotless} volcanics were formed during the 12 ± 0.5 - 15 ± 0.5 Ma time interval. Geochemical characteristics of these volcanics can be attributed to complex petrogenetic processes, including magma mixing and crustal assimilation along with fractional crystallization. © Tübi̇tak.