The Jurassic Karaburun deposit in Central Pontides is the largest known VMS deposit in Türkiye, containing ~125 Mt of ore averaging 1.16 wt. % Cu, 0.25 wt. % Zn, and 0.05 wt. % Co. Mineralization occurs within low-grade greenschist rocks of the Çangaldağ Metamorphic Complex, a tectonic unit of the Central Pontides. It is associated with volcaniclastic, detrital, and deep-marine sediments, along with cross-cutting mafic dikes and sills. The mineralization is predominantly stratiform, forming sheet-like to tabular bodies with disseminated, banded, pyritic clastic, semi-massive, and massive sulfide textures.
δ18O values of quartz in different ore textures range from 11.79‰ to 14.40‰, corresponding to calculated hydrothermal fluid values of 1.22-4.20‰ V-SMOW. Fluid inclusions with two phases (liquid + vapor) in the quartz of mineralized sections show eutectic temperatures of −10.9 to −26.0 °C, final ice-melting from −0.8 to −7.5 °C, and homogenization temperatures of 178-301 °C, with salinities of 1.4-11.1 wt. % NaCl eq. (avg. ~6.5 wt. %). Pressure corrections indicate minimum trapping temperatures of ~223 ± 25 °C. Microthermometric, oxygen isotope data and formational settings of the deposit collectively indicate ore-forming hydrothermal fluids are seawater-dominated H2O–NaCl fluids slightly and likely modified by magmatic fluids/volatiles. Narrowly constrained, non-radiogenic Pb isotope ratios (208Pb/204Pb= 37.463-37.751; 207Pb/204Pb= 15.424–15.503; 206Pb/204Pb= 18.079–18.431) indicate a mantle-derived source for lead in the massive sulfides and they also conform to the global lead evolution curve while showing temporal consistency with the growth of ore lead. |
