Mineralogy and geochemistry of granitoids and associated iron skarn of Takht (north of Kaboodar Ahang)


Department of Geology, Faculty of Sciences, Bu-Ali Sina University, Hamedan, Iran


In structural subdivision of Iran, the Takht area is located in the north of Uromieh-Dokhtar magmatic belt. According to field observations and mineralogical characteristics, the granitoids of Takht consist of granodiorite, quartz-diorite and tonalite. Intrusion of granodiorite into the Cretaceous carbonates produced iron skarn with distinctive zonation. Skarn zonation towards carbonates, include epidote, oligist-quartz, garnet, pyrite, magnetite, crystalline limestone, and carbonate zones, respectively. This distinctive zonation of skarn makes it very attractive. Based on chemical composition of garnets, there is solid solution between grossular and andradite. In spider-diagrams there are depletion of Ti, P and Eu and enrichment of Rb, U and Th LILE enrichment and depletion of HFSE. On Rb/Y+Nb diagram the granitoids of the area are I-type volcanic arc, which can be related to subduction of Neotethys oceanic crust underneath Central zone of Iran.