Fluid inclusion investigations of Deredam (Zara) polymetallic (Pb-Zn-Cu-Au-Ag) mineralization

Sivas province in Central-Northern Anatolia has an important place in our country in terms of metallic mineral deposits and industrial raw materials. Although the region is located on the border of Pontide and Anatolide tectonic deposits, at the eastern end of the Central Anatolian Crystalline Complex, it consists of many units of different ages and lithologies (metamorphics, granitoids, ophiolites, volcanic and sedimentary rocks) from Paleozoic to Quaternary. In the vicinity of the study area, lithologies belonging to Akıncılar Formation, Karataş Volcanites, Kösedağ Syenite and Isola Volcanites are observed. Mineralisation in the region is mostly observed in the brecciated silicified zones within the Middle-Upper Eocene aged syenites. Pyrite, chalcopyrite, sphalerite, galena, magnetite, hematite, rutile, fahlore and trace amounts of gold are observed in the samples taken from the unit. In the fluid inclusion studies, it was determined that salts such as NaCl, CaCl2 and MgCl2 were present in the hydrothermal solutions, the salinity values were approximately 30% (as %NaCl equivalent) and the temperature of the hydrothermal solution was approximately 390°C. The high homogenisation temperature and salinity values, the presence of different opaque minerals (hematite and chalcopyrite) and the observation of different phase types of inclusions together indicate that the mineralisation is a porphyry type mineralisation.