Abstarct: The Foroumad(Sardar) manganese deposit is located in 190 km eath of Shahrood and 8 km south of Foroumad village, within the Eocene volcano-sedimenatry sequence and in the volcanic belt of north of the Central Iran zone.The major rock units exposed in the area include Eocene andesite,basalt, tuff, marl and limestone, and Oligo-Miocene clastic unites, that extends as an E-W trending anticline.The mineralization occurred in a specific ore horizon within the Upper Eocene Nummulitic tuffaceous Limestone.Two ore facies are observed in the deposit:1)The lower facies(stringer zone) within volcanic rocks and limestone as veins-veinlets, brecciated, open-space fillings, and disseminated that ore minerals include pyrolusite, psylomelane, braunite,pyrite,barite and (2)the upper facies (stratiform zone) as laxyered and lenticular, within Nummulitic limestones and parallel and concordant with them and extends through more than 1 km as banded, laminated and disseminated that ore minerals include pyrolusite, psylomelane, manganite. Secondary mineral includes chalcosite,native Copper,malachite,some of Mn and Fe Oxides.The stratiform zone is minable. Major alteration at Sardar manganese ore deposit include chloritic-carbonate within footwall volcanic rocks and argillic alteration is surface.Fluid inclusion studies on calcite in silicic-carbonate vein witiin stringer zone show that homogenization temperature and salinity of ore-forming fluids are 212-2330C ,0.5-2.13% wt NaCl respectively.baxsed on SEM-EDS,XRD and mineralogical studies, the ore deposit contains pyrolusite,psylomelane, manganite in stratiform zone and pyrolusite, psylomelane, braunite in stringer zone and gangue minerals include calcite, chlorite, barite, pyrite, clay minerals and quartz. High ratios of Mn/Fe, La/Ce, U/Th, and Si/Al and low content of trace mextals, except of Cu; and high values of SiO2, Mn and Fe in the ores, are evidences of manganese deposition from hydrothermal-exhalative fluids in submarine environment and are separation of Fe from Mn. Positive Eu anomaly in the stringer zone indicates high concentration of Mn primarily in reduced environment and negetive Eu anomaly in the stratiform zone indicates deposition Manganese in oxides environment. The role of diagenetic process in formation of this deposit has been significant. The REE pattern of the studied ores shows a hydrothermal-exhalative origin and oxidized depositional marine environment for the stratiform deposit.The Sardar deposit, baxsed on many characteristics such as geometry, host and associated rock, textures and structures, mineralogy, alteration and geochemistry, shows the most similarities to the Intra-arc sedimentary-Exhalative deposits.