South Urals and Rudny Altai: a comparative paleovolcanic and metallogenic analysis

A comparative paleovolcanic and metallogenic analysis of two massive-sulphide-bearing regions, the Southern Urals and Ore Altai, located in different parts of the Ural-Mongolian folded belt, was performed. Comparison of the geodynamic evolution of these areas, the formation and facies composition of the ore-bearing strata and types of massive-sulphide deposits has led to the conclusion that the regions are similar only in the most general terms. Fundamental differences in the structure and composition of the crust of the regions led to differences in the profile of island-arc magmatism: basaltoid in the Southern Urals and rhyolitoid in Ore Altai. This, in its turn, determined the predominant composition of massive-sulphide mineralization: copper-zinc in the first of the regions and polymetallic — in the second. Opposite tendencies in the evolution of volcanism are also characteristic: homodromic in the Southern Urals and antidromic in the Ore Altai, which resulted in a different position of the types of massive-sulphide deposits in the ore districts: the bottom-up change of copper — massive-sulphide deposits by the massive-sulphide -polymetallic in the Southern Urals and barite polymetallic by massive-sulphide polymetallic and copper- massive-sulphide in the Ore Altai. Significant differences are also in the lateral distribution patterns of mineralization: a more pronounced control of mineralization by paleovolcanic structures of the central type in the Southern Urals and the frequent position of mineralization in intermediate and remote facies of volcanism in the Ore Altai, which is reflected in the prevalence of volcanic sections in the Urals and the majority of the volcanic sections and the larger majority of the volcanic rocks in the Ore Altai, which is reflected in the prevalence of volcanic rocks in the Urals and the majority of the volcanic sections and in the Ore Altai most of the volcanic minerals and the larger majority of the mineral rocks (20–80%) in the strata containing mineralization in the Ore Altai.