Bahatlar volkanitlerinin (Emet-Kütahya) petrografisi ve jeokimyası.

In western Anatolia, volcanic rocks in the Eocene-Quaternary age range are widely outcropped. Early Miocene volcanites are represented as andesite, dacite and rhyolites in Kütahya and its surroundings. In this study, the whole rock, Sr-Nd-Pb and O isotope geochemistry and K-Ar geochronology data of the volcanic unit consisting of rhyolites outcropping in the Emet Borate Basin will be presented. Petrographic properties of the studied volcanites are generally observed in the porphyritic vitrophyric texture, and their composition consists of plagioclase, biotite, quartz, sanidine and amphibole minerals. The major and trace element variation of the volcanites, which have calc-alkaline affinity and contain high-K, indicate that plagioclase, amphibole, biotite and alkali feldspar fractionation is effective in the evolution of rocks. In addition, high LILE and LREE and low Nb, Zr, Y and Ti contents indicate that fractional crystallization, crustal contamination and/or assimilation play an important role in the evolution of volcanites and that their main magmas are derived from an enriched source. The whole rock K-Ar aging method shows that the age of the sample belonging to the studied volcanites is 21.4±0.6 Ma. According to the obtained isotope results, (87Sr/ 86Sr)i ratio is 0.708885, (143Nd/144Nd) i ratio is 0.512347 206Pb/204Pb isotope ratio 19.04, 207Pb/204Pb isotope ratio is 15.6790 and 208Pb/204Pb isotope ratio is 37.9130 and δ18O ratio is 11.3 ‰. The obtained geochronological, geochemical, and isotopic data indicate that the investigated volcanites were formed in the volcanic arc environment and that fractional crystallization, as well as enrichment in the source mantle area and crustal pollution / assimilation (AFC) processes, have been influenced in their evolution. [ABSTRACT FROM AUTHOR]