Browsing by Author "Korkmaz, Gulin Gencoglu"

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Geochemical and Mineralogical Differentiation of Tepekent Basalts: a Multivariate Analysis Approach (NW of Konya-Central Anatolia)
(2025) Korkmaz, Gulin Gencoglu
This study investigates the mineralogical, petrographic, and geochemical characteristics of Miocene-aged basaltic rocks from the Tepekent region to distinguish and correlate them with other members of the Sulutus Volcanic Complex (SVC), particularly the Ulumuhsine and Yükselen basalts. Advanced geostatistical methods such as Principal Component Analysis (PCA), Uniform Manifold Approximation and Projection (UMAP), and k-medoids clustering analysis were applied to correlate the basaltic lava flows. While some overlaps were identified in whole-rock compositions, significant differences were observed in the mineral chemistry. The investigated basalts are primarily composed of plagioclase, with lesser amounts of olivine, pyroxene, and Fe-Ti oxides. Clinopyroxenes from the Tepekent basalts exhibit oscillatory zoning in MgO, CaO, Cr2O3, and TiO2 contents, indicating magma recharge from a more mafic mantle source. Olivine phenocrysts show disequilibrium with their host magma but are in equilibrium with the most mafic Ulumuhsine basalt, suggesting they were derived from earlier solidified phases and subsequently incorporated into the system during magma ascent or convective processes within the magma chamber. Irregular An fluctuations and sieve textures in plagioclase crystals further support the presence of magma replenishment processes. Although isotopic data are indispensable in provenance studies to definitively identify magma sources and establish genetic relationships in greater detail, this study demonstrates how mineral chemistry and geostatistical analyses can effectively differentiate basaltic lava flows and elucidate complex magma chamber processes. The findings highlight the interplay between crustal contamination, mantle-derived magma replenishment, and multi-stage magmatic evolution, providing valuable insights into the volcanic history of Central Anatolia.
Spatial Mineral Chemistry of Volcanic Rocks from the Karacadağ Volcanic Complex and Karapinar Volcanic Field (Central Anatolia): Evidence for a Trans-Crustal Magmatic System
(Springer Wien, 2025) Korkmaz, Gulin Gencoglu; Kurt, Huseyin; Asan, Kursad; Petrelli, Maurizio; Leybourne, Matthew
This research investigates the trans-crustal magmatic evolution of the Karacada & gbreve; Volcanic Complex (KCVC)-Karap & imath;nar Volcanic Field (KPVF) in Central Anatolia, with a particular focus on the major and trace element compositions of clinopyroxene and amphibole minerals from basaltic and andesitic lavas. Pliocene-aged Karacada & gbreve; andesites and Quaternary-aged Karap & imath;nar basalts contain various crystal cargoes, including crystal clots, several types of enclaves, xenocrysts, autocrysts, and antecrysts, suggesting microscale heterogeneity and potentially reflecting distinct petrogenetic histories. The EPMA results reveal that clinopyroxenes are compositionally diopside to augite, while amphiboles range from magnesio-hornblende, tschermakite, sadanagaite to pargasite. The LA-ICP-MS analyses allow for the classification of four pyroxene (Px-I to Px-IV) and six amphibole types (Amp-I to Amp-VI). Among these, Px-I, Amp-I, Amp-II, and Amp-IV exhibit relatively primitive geochemical signatures compared to their host rocks. These characteristics are consistent with crystallization from earlier, less evolved magmatic pulses, supporting their interpretation as antecrysts, whereas the others are considered as autocrysts. Thermobarometric calculations reveal that amphiboles in the KKVC suite crystallized at pressures ranging from 0.8 to 5.4 kbar, indicating magma storage across both shallow and deep crustal levels. However, those of clinopyroxenes yield 4-9 kbar and 1025-1116 degrees C, suggesting derivation from deeper reservoirs. Clinopyroxene P-T calculations for the KPVF basalts indicate high-pressure crystallization (12-14 kbar) at temperatures up to 1266 degrees C, reflecting deep crustal magma storage. All obtained data reveal open-system magma reservoirs with repeated mixing and recharge, triggering Quaternary eruptions and highlighting the role of trans-crustal magmatic system in Central Anatolia.