The Geology, Geochemistry And Genetical Features Of The Ormanbaşı Hill (Sincik, Adıyaman) Copper Mineralization

The study area covers Ormanbaşı Hill of Adıyaman?Sincik County and its vicinity. Regional geological locations of Cu mineralizations that lie between the Southeastern Anatolian Foothill Belt and Taurus Orogenic Belt are conformable with thrust planes approximately extending in E-W directions. Cu mineralizations are observed in the form of lenses and layers within mudstone, diabase, spilite and claystone - shales of the Koçali complex. The primary genetic relations of these formations have completely been disappeared but have only been traced along thrust planes that are conformable with general tectonic lineaments. The ore structure is generally massive but is stockwork and disseminated in some zones. The ore bearing layer with pyrite towards deeper parts is observed, while the mineralization is observed in the form of iron ore cap (gossan) at surface. Ore paragenesis consists of pyrite, marcasite, chalcopyrite, sphalerite, bornite, chalcosine - covelline and native copper. All samples belonging to ore mineralizations plot on Cyprus type volcanogenic massive sulfide (VMS) area in Cu ? Pb - Zn and Au - (Cu + Pb + Zn) - Ag ternary diagrams. All samples in Pb, Cu, Ag, Au and Zn spider diagrams which were normalized to primary mantle show a trend similar to VMS deposits. Besides, analyses carried out in massive pyrites indicated that these had Ni/Co ratio higher than 1% and less Ni content. Therefore; it was detected that hydrothermal processes had been affective in ore mineralizations. S32/S34 ratios were obtained as 6.9 and 7.6 in sulfur isotope analyses performed by using pyrite and chalcopyrite samples. These values are both compatible with sulfur ratios in hydrothermal solutions related to volcanism and show a similar composition with that of Cyprus type VMS deposits on the world.