Petrography and petrology of The Yurekli (Balikesir) volcanics: an example of post-collisional felsic volcanism in the Biga peninsula (nw Turkey)

Abstract

In this study, it is aimed to determine to petrographical, geochemistry and sources of the Yurekli volcanics (Biga Peninsula, NW Turkey). Tertiary volcanism is widespread in Western Anatolia (NW Turkey), is an important area where tectonic and magmatic events are observed together. Yurekli volcanic rocks composed of dacitic lavas and pyroclastics. Dacitic lavas show porphyric and hyaloporphyric texture, and consisting of plagioclase, quartz, amphibole, biotite, sanidine and Fe-Ti oxide minerals with apatite and zircon accessory minerals. Petrologically, it is high-potassic and calc-alkaline in characteristic. Yurekli volcanics show enrichment in large ion litophile elements (LILE) while depletion in high field strength elements (HFSE) on the N-MORB normalized diagram. On the chondrite-normalized rare earth element (REE) plot, light rare earth elements are enriched but heavy rare earth elements are depleted in the rocks. Besides, REE patterns are concave shaped (mean LaN/LuN=16-25), and show a slight negative Eu anomalies (0.66-0.81). Plagioclase, amphibole and biotite fractional crystallization and crustal assimilation are important in the evolution of the Yurekli volcanics. According to all data, it can be argued that the Yurekli volcanics is formed in the post-collisional setting, and their parental magmas have derived from the melts of enriched lithospheric mantle.