The Ushkatyn-III deposit is located in Central Kazakhstan, 300 km west of the city of Karaganda. It is classified as weakly metamorphosed hydrothermal-sedimentary ore deposit of the Atasu type. Stratiform layers of iron, manganese and barite-lead ores are present in the Upper Devonian (D3fm2) carbonate stratum of this deposit. The objects of present study are iron and manganese layers. Iron ores are composed of hematite, calcite and quartz. Among the manganese ores, two types could be distinguished: braunite and hausmannite. Braunite ores are composed of braunite, calcite, quartz and albite; hausmannite - by hausmannite, rhodochrosite, manganese calcite, tephroite (sometimes with sonolite and alleghanyite) and friedelite. The mineral composition of the ores was formed during the burial of metal-bearing sediments containing oxides of Fe3+ and Mn3+/Mn4+. The nature and intensity of the post-sedimentation processes were controlled by the content of organic m
