The studied manganese prospects within ophiolitic complexes are located in southeast of Birjand, South-Khorasan, east of Iran. The ophiolitic sequence in this region hosts manganese ores occurring as small discrete patches associated with radiolarian cherts and shales. The major manganese ore minerals are pyrolusite, braunite, bixbyite, ramsdellite, and romanechite showing replacement, colloidal, and brecciated textures. The major non-opaque gangue minerals are, calcite, silica and gypsum. The high mean values of Mn/Fe (15.32) and Si/Al (15.65), and low mean concentration values of rare elements like Cu (86 ppm), Ni (250 ppm), and Zn (149 ppm), and high Ba (average 1883.77 ppm), with low Pb (average 52ppm) and low Ce (average 15.7 ppm), also The Co/Zn (average 1.055), Ce/La ratio (average 2.96) suggest a distal hydrothermal source. Investigations on fluid inclusions hosted by calcite demonstrate that the ore-forming solutions had salinities within the range of 0.5-4.5 wt% NaCl eq., homogenization temperature range of 100-220˚C and density about 0.8-1 g/cm³. The pressure was estimated to be about 50 bars, corresponding to a depth of ~150 meters at the time of formation. Fluid inclusion data are interpreted as evidence for formation from seafloor Mn-rich hydrothermal exhalative fluids. Hydrogenous processes played no significant role in ore genesis. The geological and geochemical results also revealed that deposition of the ores occurred in the upper parts of the ophiolitic sequence by submarine exhalative processes. Intense hydrothermal activities caused leaching of elements such as Mn, Fe, Si, Ba, As, and Sr from basaltic lavas (spilites) through concurrent faults with deposition. These elements were fed to a sedimentary basin and during retreat of the sea accompanied by onset of oxidising conditions. The primary manganese minerals were Mn oxides and hydroxides which have gradually been converted to psilomelane and finally pyrolusite, braunite and bixbyite. During deposition of Fe and Mn from hydrothermal solution, they became decoupled from one other, producing different Mn/Fe ratios in sedimentary exhalative deposits (sedex-type). The Mn/Fe ratios are 3.99 to 40.81 (ave., 15.32). Very high and very low ratios of Mn/Fe can be interpreted as fractionation and separation of these two elements from transportation during hydrothermal activity and mineralization. So, high Mn/Fe ratios here can be considered as in submarine hydrothermal deposits. On a Pb versus Zn diagram, the manganese prospects display greater similarities with sedex deposits.