Davulalan -Yaylagöze (Yıldızeli-Sivas) rare earth elements in thesurrounding syenitic rocks geochemistry

This study aims to investigate the geochemical characteristics of rare earth elements (REEs) within syenitic and alkaline magmatic rocks located in the Davulalan–Yaylagöze (Yıldızeli–Sivas) region, situated in the Central Anatolian Crystalline Complex (CACC). The Upper Cretaceous–Paleocene aged alkaline plutonic rocks in the study area comprise lithologies such as syenite, foidolite, foid monzosyenite, foid monzodiorite, and monzogabbro, exhibiting significant variations in REE concentrations. The research is based on over 1,400 core samples collected from four exploratory drill holes (21-15, 21-21, 21-23, and 22-4) conducted by the General Directorate of Mineral Research and Exploration (MTA). Whole-rock geochemical and REE analyses were performed, and results were evaluated using classification and tectonic discrimination diagrams, including Na₂O+K₂O–SiO₂, A/NK–A/CNK, Zr+Nb+Ce+Y–Fe₂O₃/MgO, and Yb–Ta. Results indicate that alkaline rocks such as foidolite, foid monzodiorite, and foid monzosyenite host ΣREE values reaching up to 2000 ppm, with significant enrichment zones observed especially between 180–220 meters in drill holes 21-23 and 21-21. These intervals represent both primary magmatic evolution and potential hydrothermal overprinting. Chondrite-normalized REE patterns display typical LREE enrichment, HREE depletion, and distinct negative Eu anomalies, suggesting crystal fractionation, garnet stability, and crustal contamination processes. The geochemical data indicate that these rocks crystallized within a subduction-related arc setting, consistent with the tectonomagmatic evolution of the Central Anatolian Crystalline Complex. Ratios such as Ce/Pb and Nb/U further support the influence of sediment-derived melts and altered oceanic crust components in the source region. Overall, the investigated rocks display substantial REE potential, providing both economic insights and contributing to the understanding of regional geodynamic processes. Keywords: Rare Earth Elements (REE), Syenite, Foidolite, Alkaline Magmatism, Central Anatolian Crystalline Complex, Geochemistry, Sivas–Yıldızeli