Abstarct: Abstract Iron-copper-barite deposits in the Ahmadabad region are located 35 km northeast of Semnan and in the northernmost part of the magmatic belt of Central Iran in the Eocene volcanic-sedimentary sequence equivalent to Karaj Formation. The rock units of this sequence from bottom to top are: unit 1- involving conglomerate and limestone, unit 2- comprised of andesitic lavas and unit, and 3- which includes tuff and shale. Also, some Eocene basic to intermediate intrusions are present in the area. Mineralization in this region is mostly hosted by tuff, which were explored and exploited as industrial clay 1 and 2, Ahmadabad iron-copper, Emami barite, Zareei iron, and Moshirieh iron-barite deposits. Ore facies in these deposits from the bottom to top are: 1- vein-vein facies which is seen in all soil and deposits as cross-cuting veins, 2- brecciated facies 3- massive ore, Which is present in Emami barite ores and Zareei iron ore, Moshiria iron-barite and Ahmadabad iron-copper deposits. Mineralogically, the primary minerals in these mineralizations are pyrite, barite, specularite, magnetite, chalcopyrite, galena and secondary minerals including goethite, malachite, covelite and limonite. Major gangue minerals include chlorite, quartz, and gypsum. Main alterations in the industrial clay deposits are argillic and chlorite, and in the Ahmadabad iron-copper deposit involve sericitic in the center and chloritic at margins, and in the Moshirieh, is mainly chloritic. According to geochemical studies, silver is concentrated in the vein-vein facies, and its amount reaches 6.5 ppm in the industrial clay deposits. Silver shows a positive correlation with lead and zinc and a negative correlation with copper, which indicates the placement of silver in the galena structure. The volcanic and intrusive rocks of the region are geochemically calc-alkaline in nature, formed in volcanic arc setting. According to the above evidences, occurrence of mineralization in a special stratigraphic horizon (same horizon of Poshteh, Vankan and Moshirieh deposits), ore facies and tectures, mineralogy, and alterations, the ore deposits in the area including the Ahmadabad iron-copper and Moshirieh iron-barites could be classified as immature Kuroko-type volcanogenic massive sulfide (VMS) deposits. baxsed on investigations, the Ahmadabad and industrial clay deposits were formed at subseafloor replacement in tuff, and some parts of the Moshirieh deposit formed at the seafloor.