Ore facies, geochemistry and genesis of Kuhe Rig Fe-Sr-(Mn) deposit, South of Shahroud

Kuhe Rig iron- strontium-(manganese) deposit is located in south of Shahrood, in the northern part of the central Iran zone. Mineralization occurred in the Eocene volcano-sedimentary sequence dominated by andesite basalt, basalt and crystal lithic tuffs. Geometry of main ore body is lense-shaped which is concordant with lithic tuff host rock layering. Vein-Veinlet mineralization occurs beneath the main ore lense. Based on stratigraphic position, mineralogy, and texture of mineralization, three different ore facies can be distinguished: vein-veinlet (feeder zone), bracciated ore and banded ore facies. Ore minerals includes: goethite, hematite, magnetite, celestite, pyrolusite, psilomelane, barite and iron hydroxides which are accompanied by calcite and quartz gangue minerals. Sericitization and chloritization are the main wall-rock alteration styles. Based on volcono-sedimentary host sequence, geometry of ore body, ore textures and facies, mineralogy, alteration zones and geochemical features, Kuhe Rig can be classified as volcanic-exhalative iron deposits. It's worth mentioning that high amounts of celestite is of special characters of the mineralization in Kuhe Rig deposit and any similar deposits has not been reported in Iran and the world.