Browsing by Author "Kadioglu, Yusuf Kagan"

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    New Palaeolimnological Record From West Anatolia (paleo-Kuleonu Lake) Provides New Information on the Activity of the Golcuk Volcanism and the Distribution of the Santorini Minoan Eruption
    (Wiley, 2025) Senkul, Cetin; Unlu, Yasemin; Ozdemir, Yavuz; Kadioglu, Yusuf Kagan; Guerboga, Sule
    Anatolia, which had active volcanoes during the Pleistocene and Holocene periods, was also influenced by volcanic eruptions around the Eastern Mediterranean. Therefore, tephrochronology is an important research topic in palaeoenvironmental studies conducted in Anatolia. This study focuses on the geochemical characteristics, chronologies and source areas of six different tephra layers identified in a 16 m sediment core obtained from Paleo-Kuleonu Lake in the Lake District of West Anatolia. Whole-rock geochemistry is used to determine the geochemical characteristics and source of the tephra layers, micro X-ray fluorescence analysis is used to determine relative element changes throughout the cores, and C-14 analysis is performed to establish the chronologies. The geochemistry of the Paleo-Kuleonu Lake tephra layers is consistent with the Golcuk volcanism located in West Anatolia province and the Minoan eruption within the Aegean volcanic province. The layers that resemble the geochemistry of the Golcuk volcanism accumulated at similar to 33 218 cal a BP (PLK-19-1; 30 cm), similar to 32 267 cal a BP (PLK-19-2: 18 cm), similar to 31 597 cal a BP (PLK-19-3; 8 cm), similar to 31 300 cal a BP (PLK-19-4; 17 cm) and similar to 26547 cal a BP (PLK-19-5; 13 cm) and are associated with the last eruptive cycle (Cycle III) of the volcanism. The closest tephra layer to the surface in the sediment core, designated as PLK-19-6 (similar to 1.5 cm), shows geochemical similarities with the Santorini Minoan eruption. However, according to our data, the age of the tephra layer is similar to 4717 BP/similar to 5542 cal a BP, which is inconsistent with the widely accepted date for the Minoan eruption in the literature. The discrepancy between the geochemical match and chronological inconsistency is discussed in the context of the results presented in the paper. (c) 2025 John Wiley & Sons, Ltd.
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    Petrogenesis of Rift Related Marginal Basalts From the Asal-Ghoubbet Rift Area, Republic of Djibouti: Implications for Magma Genesis and Mantle Source Characteristics
    (Elsevier GmbH, 2025) Iltireh, Awaleh Djama; Kadioglu, Yusuf Kagan; Ozdemir, Yavuz; Awaleh, Mohamed Osman; Mohamed, Jalludin
    This research investigates the Marginal basalts in the Asal-Ghoubbet rift, a poorly understood geological feature, with the aim of clarifying magma sources and identifying the mantle reservoir responsible for forming basaltic rocks in the region. The study involved analysing major geochemical elements, rare earth elements and radiogenic isotopes of Sr, Nd and Pb from basalt samples collected in the Marginal basalts of the rift. Additionally, the mineral composition of plagioclase, olivine, pyroxene and Fe-Ti oxides was examined using electron probe microanalysis (EPMA) on polished thin sections. Geochemical results indicate a tholeiitic composition for the Marginal basalts, with evidence of fractional crystallization driven initially by clinopyroxene and olivine, followed by plagioclase crystallization. Thermobarometric and MELTS modelling estimated magma storage depths ranging from the Moho to the upper crust. The basalt is slightly enriched in light rare earth elements (LREEs) and depleted in Heavy Rare Earth Elements (HREEs), similar to the characteristics of enriched Mid-Ocean Ridge Basalt (E-MORB) and Ocean Island Basalt (OIB). Isotopic data of Sr and Nd reveal sources that vary between the high mu mantle source (HIMU) and the dominant prevalent mantle source (PREMA). Furthermore, Pb isotopic signatures suggest an influence from an enriched mantle (EM) component, plotting between the EMI and EMII mantle reservoirs fields. Forward-melting modelling and isotopic evidence suggest that the Afar mantle plume is a significant contributor to the magma source of Marginal basalts in the Asal-Ghoubbet rift. Overall, the study enhances understanding of the magma plumbing system in this area, elucidating the process governing magma chamber evolution and the nature of the mantle reservoirs that generated these basaltic rocks.