Akademik Veri Yönetim Sistemi
TURKISH JOURNAL OF EARTH SCIENCES, cilt.35, sa.1, 2026 (SCI-Expanded, Scopus, TRDizin)
The magnesite deposit of the Edige region in Ankara-Elmada & gbreve; District of T & uuml;rkiye is hosted in serpentinite/serpentinized ultramafic rocks, which are mainly harzburgite and dunite. Mineralogical and petrographic studies have shown that ultramafic rocks are composed of serpentine, olivine, and pyroxene with serpentinization preceding magnesite formation. The X-ray diffraction results reveal that dolomite, quartz, calcite, and clay minerals are the main minerals in magnesite samples from serpentinite/serpentinized ultramafic units. Olivine, pyroxene, serpentine, chromite, and iron oxide minerals are also present. Scanning electron microscopy and energy dispersive spectrometry results show that magnesite in rhombohedral and cryptocrystalline forms is the dominant mineral accompanied by dolomite and quartz. The geochemical data show high MgO values between 33.3% and 37.2% and SiO2 values between 37.3% and 42.9%, indicating peridotite characteristics. The CaO values are very low, with an average of 1.01%, and the Al2O3 values are between 0.2% and 1.8%. These results also suggest that peridotite rocks formed through partial melting of a depleted mantle source. Stable carbon (delta 13C) and oxygen (delta 18O) isotope data indicate magnesite formation at shallow depths through low-temperature diagenetic processes, with delta 13C values between-13.62%o and-10.54%o Vienna Pee Dee Belemnite (VPDB) and delta 18O values between-3.51%o and-2.01%o VPDB corresponding to 27.29%o to 28.84%o Vienna Standard Mean Ocean Water. These data suggest that the carbon came from organic-rich sediments and fluids influenced by meteoric waters.