Mineralogical and geochemical characteristics of mineralizations in the maden tepe (Zara - Sivas) region

This thesis study was conducted in the Maden Tepe locality, situated between the Zara and Suşehri districts in the northeastern part of Sivas Province. The study area is characterized by the presence of Middle–Upper Eocene-aged Karataş Volcanics, which are intruded by the younger Middle–Upper Eocene-aged Kösedağ Syenites. In order to determine the mineralogical and geochemical characteristics of the observed polymetallic mineralizations in the region, samples were collected from drill cores, host rocks, ore-bearing rocks, and sediments. Under the coordination of the General Directorate of Mineral Research and Exploration (MTA), a total of seven core drillings were conducted in 2014 to identify mineralizations in the region. Petrographic analyses of rock samples obtained from the drill cores and surface outcrops revealed that the Karataş Volcanics are represented by andesite and basalt, whereas the Kösedağ Syenites are composed of syenite, monzonite, and minor amounts of alkali microgranite. Along the main fault zone in the study area, known as the Maden Stream, a hot-hot contact relationship is observed between the Karataş Volcanics and the Kösedağ Syenites. Intense alteration is present in this zone. Polished thin sections prepared from ore-bearing rock samples were examined under an ore microscope, identifying the presence of minerals such as chalcopyrite, pyrite, magnetite, leucoxene, rutile, sphene, ilmenite, ilmenomagnetite, covellite, marcasite, hematite, limonite, and digenite. Additionally, X-ray diffraction (XRD) analyses performed on selected ore-bearing rock samples revealed ore-forming minerals such as galena, fayalite, sphalerite, anglesite, magnetite, jarosite, goethite, and alunite. Chemical analyses of drill core samples from the Maden Tepe region indicate localized enrichments in Au, Ag, As, Cu, Pb, Sb, and Zn. Major oxide and trace element contents were determined for 15 samples taken from the Köse Dağ Syenites and mineralized zones. Variations of these contents against SiO₂ were examined and plotted in variation diagrams.As part of the fieldwork, 23 stream sediment samples were collected. These samples revealed anomalies in As, Cu, Pb, and Zn concentrations. Anomaly maps were generated using the Surfer software. Geochemical evaluation of rocks from the Maden Tepe area indicates that the regional rocks exhibit alkaline characteristics, and the Köse Dağ Syenites belong to the shoshonitic series. The mineralized rocks, on the other hand, show a calc-alkaline character. Geological, mineralogical, and geochemical studies conducted in the area suggest that the mineralization is of vein-type polymetallic nature, containing Cu, Pb, Zn, Au, Ag, and Sb.