Petrography and geochemistry of the Kötüdağ (Emirgazi-Konya) volcanites

In this study, studies were carried out to examine the volcanic rocks outcropping in an area of 20 km2 around Emirgazi in the southeast of Konya in terms of petrographic and geochemical to reveal the relationship between the geology of the region and magmatism. In the examinations made, the place and importance of the rocks in the Central Anatolian Cenozoic volcanism were examined and it was tried to contribute to the literature about the petrography and geochemistry of the region. Volcanostratigraphy and petrographic and geochemical properties of Neogene aged volcanic rocks outcropping around Üzecikdağ and Kötüdağ (Emirgazi-Konya) in the study area are presented. Neogene aged volcanic rocks with intermediate-acidic composition, represented by lava flows/domes and their pyroclastics in the study area, were named as "Kötüdağ volcanics". Kötüdağ volcanics differ morphologically, petrographically and geochemically from Hasandağ medium-felsic rocks and Karacadağ medium-felsic rocks outcropping in the region. It contains different types of andesite according to its textural, mineralogical and chemical content. Kötüdağ volcanics have plagioclase + amphibole + biotite ± clinopyroxene phenocryst mineralogy. Andesite-1 type rocks outcropping around Kötüdağ have macroscopic and microscopic higher mafic mineral content, while Andesite-2 type rocks outcropped around Üzecikdağ have more felsic mineral mineralogy and contain less magma mixing enclave. The investigated volcanics commonly display instability textures such as zoning-sieve texture in plagioclases and also contain opaque opacified amphibole-biotite pseudocrystals. Kötüdağ volcanics, which are classified as basaltic andesite and andesite in the TAS diagram, show calc-alkaline (subalkaline) geochemical characteristics and Andesite-1 type rocks are located in the low potassium series area in the SiO2-K2O- diagram. Andesite-2 type rocks are located in the high potassium series area. Kötüdağ volcanics show LILE (Rb, Ba, Sr, K) enrichment, negative Nb-Ta and positive Pb anomaly, typical for orogenic or continental crust-contaminated magmas in NMORB-normalized unconformable trace element diagrams. It also exhibits moderately enriched LREE (LaN/LuN: 5.15-9.83) and spoon-patterned HREE (DyN/YbN: 0.84-1.055) patterns indicating amphibole fractionation. The first geochemical and petrographic findings show that the Neogene aged Kötüdağ volcanics contain different types of andesite, which differ significantly from the other Neogene volcanics in the region (Karacadağ and Hasandağ).