Geology, ore mineralization and geochemistry of Sorkheh sedimentary copper occurrence, northwest of Marand, NW Iran

The sedimentary copper mineralization of the Sorkheh area is located about 20 km northwest of Marand, East-Azarbaidjan Province, northwest Iran. The most important lithologic units in this area include sandstones and red-color shales, with the Late Miocene age, that are intruded by lamprophyric dike. The copper mineralization in the study area occurred as stratiform laminations and disseminations hosted by sandstones and shales and as open-space filling textures within lamprophyric dike. The ore mineralization in the sandstones consists of chalcopyrite, bornite, chalcocite, tetrahedrite, covellite, native copper, and cuprite. This study showed that mineralization is associated with weathering and leaching of the lamprophyric dike . Also, deposition of copper in sandstone units can be related to trapping of organic matters. Activity of the hydrothermal fluids, presence of abundant organic matters, function of diagenetic processes, existance of the geochemical barriers (organic matter and silicification), and the active tectonic in the area played crucial roles in this ore mineralization.