%0 Journal Article %T Eocene Masjeddaghi porphyry Cu-Au deposit; an example of island arc porphyry type deposit in NW Iran %J Scientific Quarterly Journal of Geosciences %I Geological Survey of Iran %Z 1023-7429 %A Hassanpour, S %A Alirezaei, S. %D 2017 %\ 08/23/2017 %V 26 %N 104 %P 43-58 %! Eocene Masjeddaghi porphyry Cu-Au deposit; an example of island arc porphyry type deposit in NW Iran %K Porphyry Cu-Au %K Masjeddaghi %K Island Arc %K Eocene %K Azerbaijan %K Iran %R 10.22071/gsj.2017.50166 %X The Masjeddgaghi Cu-Au deposit is located to the southeast of the Arasbaran zone, NW Iran, to the south of the Lesser Caucasus. Mineralization in Masjeddaghi is associated with an Eocene dioritic subvolcanic pluton intruded into older volcanic and sedimentary rocks. The Masjeddaghi intrusive body is high-K, calc alkaline, and meta-aluminous, and formed in an island arc subduction/collision setting. Hydrothermal alteration is distinguished by a potassic core marked by secondary biotite and K-spar that grades outward into a chlorite-rich propylitic halo. The ore minerals include chalcopyrite, associated with minor chalcocite, bornite, tetrahedrite, and trace molybdenite. Pyrite and magnetite are common associates. The Masjeddaghi deposit is elliptical in plan view, 500 x 400 m in diameters, and mineralization has been traced for several hundred meters from surface exposures. 40Ar/39Ar geochronology on secondary biotite from potassic alteration zone indicates that mineralization, and by corollary, the emplacement and crystallization of the Masjeddaghi porphyritic intrusion, occurred in 54.07 ± 0.53 Ma. The Masjeddaghi ore deposit shows geology, mineralization and alteration characteristics comparable to those typical of island arc type porphyry Cu-Au systems. Masjeddaghi ore deposit shows geology, mineralization and alteration characteristics similar to island arc porphyry type systems. %U http://www.gsjournal.ir/article_50166_b8bc884fc34b5f244b91175b82c4d0ff.pdf