Geodynamic setting of middle miocene granites in the Menderes massif and implications for the Aegan extensional tektonics

The Western of Turkey, which forms the eastern part of the Aegean region, was subjected to continental extension that led to the formation of metamorphic core complexes and associated syn-extensional granitoids. This study deals with the syn-extensional Salihli, Turgutlu granitoids in the Menderes metamorphic core complex (MMCC). Geochemical data have been used to classify these granitoids, to determine their geochemical characteristics, and to estimate the possible source regions and tectonic environment of magma generation and emplacement. I have also attempted to correlate the geochemical features and geodynamic setting of the syn-extensional granitoids in the MMCC with those of the granitoids in the metamorphic core complex. Salihli and Turgutlu granodiorites have granitic and granodioritic compositions and contain mafic microgranular enclaves (MMEs) of monzonitic-monzodioritic composition. They show transitional metaluminous/peraluminous, high-K, calc-alkaline and I type character. The SiO2 versus major element plots of consistently show regular distribution patterns and negative correlation for Al2O3, Fe2O3, MgO, CaO, Na2O, TiO2, P2O5, Sr, Y, Nb, Zr, but positive correlation for K2O, Ba, Rb, Th. All intrusive rocks display enrichment in large ion lithophile elements (LILE). The granodiorites of Salihli and Turgutlu are geochemically similar to the another syn-extensional granitoids. Retreat of the Aegean subduction zone seems to play a major role for development of extensive metamorphic core complexes and associated syn-extensional granitoids in the Aegean region.