EGU23-13798, updated on 26 Feb 2023
https://doi.org/10.5194/egusphere-egu23-13798
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Evolution of the hydrothermal fluids of the Yolindi Fe-Cu skarn deposit, Biga peninsula, NW Turkiye: Evidence from carbon-oxygen isotopic variations of calcite minerals

Mustafa Kaya1, Mustafa Kumral1, Amr Abdelnasser1,2, Cihan Yalçın3, Sercan Öztürk1, Hatice Nur Bayram1, and Beril Tanç-Kaya1,4
Mustafa Kaya et al.
  • 1Istanbul Technical University, Faculty of Mines, Geological Engineering, Istanbul, Türkiye
  • 2Geology Department, Faculty of Science, Benha University, Benha, 13518, Egypt
  • 3Ministry of Industry and Technology, General Directorate of Industrial Zones, Ankara, Türkiye
  • 4Istanbul Technical University, Graduate School, Nanoscience and Nanoengineering, Istanbul, Türkiye

This work deals recently with the carbon (δ13C) and oxygen (δ18O) isotopic variations in the calcite associated with the hydrothermal mineralization to comprehend the nature of the ore fluid and its source and the evolution of the Yolindi Fe-Cu skarn deposit at North of Biga peninsula (NW Turkiye). The Yolindi area is made up of Torasan Formation (marble, hornfels, phyllite, and schist) which was intruded by Oligocene Hallaçlar volcanic rocks and later early Miocene Şaroluk plutonic rocks. The Yolindi Fe-Cu skarn deposit has been formed along the eastern contact of Şaroluk pluton with the Torasan Formation having widespread prograde and/or retrograde skarn, silicic, and carbonate (calcite) alteration. The prograde skarn is less observed and characterized by formation of garnet with subordinate magnetite. While, the retrograde skarn is highly extensive having epidote, actinolite, chlorite, and carbonate including pyrite, magnetite, chalcopyrite, and specular hematite with subordinate sphalerite and galena. Malachite, azurite, goethite, hemimorphite, and cerussite represent the supergene minerals which locally replaced Fe-oxide and Fe-Cu±Zn±Pb sulfide minerals. At the Yolindi Fe-Cu skarn deposit, carbon and oxygen isotope ratios of calcite minerals from the exoskarn zone are -15.5 to -2.0 ‰ relative to PDB and 0.9 to 17.9 ‰relative to V-SMOW, respectively. Furthermore, it was inferred from the calculated carbon isotopic composition of an ore-forming fluid (δ13CCO2 = -12.7 to +0.8 ‰) that the carbon in the fluid is identical to the reduced carbon in sedimentary and metamorphic rocks. However, the calculated fluid's δ18OH2O values—which vary from 0.9 to 17.2 ‰VSMOW—indicate a mixture of metamorphic and magmatic origins for the hydrothermal fluid. This fluid mixing which has high range of C-O isotopic compositions has been due to a temperature effect along with either CO2 outgassing or fluid/rock interactions. Additionally, the mineralizing fluid is most likely derived from the metamorphic dehydration of carbonate rocks in the Torrasan Formation during Yolindi skarn formation.

Keywords: carbon (δ13C) and oxygen (δ18O) isotope; Fe-Cu Yolindi skarn deposit; Biga peninsula; NW Turkiye

How to cite: Kaya, M., Kumral, M., Abdelnasser, A., Yalçın, C., Öztürk, S., Bayram, H. N., and Tanç-Kaya, B.: Evolution of the hydrothermal fluids of the Yolindi Fe-Cu skarn deposit, Biga peninsula, NW Turkiye: Evidence from carbon-oxygen isotopic variations of calcite minerals, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-13798, https://doi.org/10.5194/egusphere-egu23-13798, 2023.