Petrology and geochemistry of volcanic rocks from the north of Beypazari, Ankara

In this thesis, the petrological and geochemical properties of the volcanic rocks in the north of Beypazarı, which form the western part of the Galatia Volcanic Province (GVP) located in the north of Ankara, were examined, and it was aimed to reveal the processes that were effective in the origin and formation of volcanism. It was determined that the volcanic rocks in the region were formed in the Early Miocene (18.3-16.9Ma) period according to the results of the age analysis performed in this study. It has been determined that the volcanic rocks in the study area are from old to young, andesitic, dacitic, basaltic tachyhandesite composition, and acidic and intermediate volcanic rocks show adakitic properties. According to the major-trace element, rare earth element and isotope data, the volcanic rocks in the study area were formed by low-grade partial melting (4-8%) from an enriched lithospheric spinel-peridotite source under conditions where the subduction process is also effective, It has been determined that assimilation and fractional crystallization processes are effective in their formation. Keywords: Galatia, Beypazarı, geochemistry, adakite, low-grade partial melting