Comparative investigation of Esendemir tepe skarn and Horoz skarn mineralizations in Ulukışla (Niğde) basin

The Ulukışla Basin has formed in the post-collisional tectonic environment on the suprasubducted Alihoca Ophiolitic Complex caused by the collision of the Niğde Massif from the north and the Tauride Carbonate Platform from the South, until Upper Cretaceous, and is a result of the post-collisional tectonic environment. As a part of this post collisional extensional regime; the Ulukışla Formation consists of magmatic, volcanic, volcano-sedimentary and limestone units. The Esendemirtepe Diorite (60-56 Ma) located in the Ulukışla Formation, has been exposed to ore forming processes leading to the occurrence of skarn type mineralization in the limestone levels within the volcano-sedimentary unit. In the prograde stage of this skarn type mineralization, biotite, garnet, pyroxene, magnetite have been formed, respectively. Amphibole, chlorite, epidote, hematite are the phases that occur in the retrograde stage. In the hydrothermal stage; quartz, calcite, chalcopyrite, pyrite, fahlerz(?), and digenite are formed. The supergene stage is characterized by the occurrence of chalcocite(?), malachite, azurite, hematite and limonite. After the occurrence of the Ulukışla Formation from the extensional tectonic setting, the Horoz Granitoid (56-47 Ma) has been intruded into the Tauride Carbonate Platform during the later collisional tectonic regime. The skarn zoning formed by the Horoz Granitoid is determined as; endoskarn, garnet skarn, and the roof pendant. Garnet is formed in the prograde stage of this later skarn mineralization. The retrograde stage is characterized by occurrence of amphibole, chlorite, and epidote, respectively. Quartz, calcite, chalcopyrite, and pyrite assemblage occurs in the hydrothermal stage. The supergene stage of this skarn mineralization is characterized by occurrence of -some probably arsenic bearing- iron oxides/hydroxides (arsenic bearing hematite, limonite, goethite-lepidocrocite, and probably scorodite/arseniosiderite(?) and rarely malachite. Geochemically, both Esendemirtepe Diorite and Horoz Granitoid presents characteristics of the hydrated-oxidized magmas that are usually correlated with the occurrence of the porphyry-type mineralizations.