Magma nature and tectono-magmatic context of the Eocene Uludağ granitoids (NW-Türkiye): Insights into the Cenozoic geodynamics of the Tethyan Orogenic Belt

Late Paleocene to Middle-Eocene magmatism provides critical insights into the reconstruction of the Cenozoic geodynamic evolution of NW Anatolia. In this study, we mapped individual petrographic facies from the Eocene Uludağ Plutons (Topuk and Tepeldağ) and present zircon U-Pb geochronology, Sr-Nd isotope data, and comprehensive geochemical analyses for the entire plutons. We examined the Delice tonalite-granodiorite (D4) and Delice alkali-feldspar granite (D8) from the Topuk Pluton, as well as the Southern Tepeldağ quartz-monzodiorite (ST1) from the Tepeldağ Pluton. U-Pb zircon ages were 54.56 ± 0.21 Ma for ST1, 47.35 ± 0.21 Ma for D4, and 45.90 ± 0.29 Ma for D8. Initial Sr/Sr and Nd/Nd values were calculated, showing 0.706693 and 0.512428 for ST1, 0.707309 and 0.512452 for D4, and 0.705896 and 0.512448 for D8, respectively. The new zircon U-Pb ages for these facies cover nearly the entire interval from 54 to 45 Ma, enabling a comparison of magma evolution with the Late Paleocene to Middle-Eocene (58–45 Ma) magmatism.