Petrological properties of quaternary volcanic rocks around the Elaziğ region

In this study, it was aimed to investigate the lithology, petrographic and geochemical properties of the Neogene-Quaternary aged volcanic rocks in the vicinity of Elazığ. In the study, mineral chemistry analyzes, whole rock and isotope (Sr-Nd) analysis data were evaluated together with previous studies. Elazığ volcanics, which is defined in the Eastern Anatolia Volcanic Provence, consisted of lava flows and pyroclastic rocks in the study area. While lava flows do not form large thicknesses, pyroclastic rocks that generally form basaltic slag cones are relatively much thicker. In petrographic studies, it was determined that these rocks have little alteration and consist of olivine basalts that generally show porphyric, vesicular and flow texture. The main mineral composition of these rocks consists of plagioclase, olivine, less pyroxene or amphibole mineral. With the evaluation of the chemical analysis data of the minerals, plagioclase minerals generally vary between anorthite and sanidine along with labradorite and andesine. While pyroxene minerals are diopside and clinoenstatite in composition, element distributions in olivine minerals point to magma mixing together with homogeneous magma. According to the evaluation of all rock analysis results in naming diagrams, it has been determined that the volcanics have silica-unsaturated alkali properties and the composition of potassic trachybasalt, hawaiite and basanite belonging to high-K alkaline series. In Harker diagrams showing the variation of major and trace elements with SiO2, it is seen that all samples evaluated in terms of element contents are generally compatible with each other. Similar distribution is also seen in the multiple element variation diagrams normalized to chondrite and primary mantle. Low 87Sr/86S(i) and high 143Nd/144Nd(i) contents of volcanics indicate the depleted mantle source region. Mineralogical and geochemical data show that all volcanics are partly affected by upper crust contamination as well as fractional crystallization, which has post-collisional intraplate basalt and low partial melting point.