Central Asia––A Global Model for the Formation of Epigenetic Deposits in a Platform Sedimentary Cover

Metallogenic specialization of sedimentary cover in Central Asia is determined by its tectonic setting that governs the hydrodynamic regime (exfiltrational or infiltrational) and as a consequence, the hydrogeochemical zonality (type of water and its gaseous and microcomponent composition). Hydrodynamic conditions (distribution of recharge and discharge areas) determine the direction of stratal water flow and location of mineralization resulted from the change in geochemical, thermodynamic, lithological, structural and other conditions. The exfiltrational regime suggests a dependence of the epigenetic mineralization upon the distribution and degree of preservation of hydrocarbon occurrences. Often, hydrocarbon matter serves as a reducing barrier and ore-concentrating factor during the formation of polymineral concentrations related to stratal oxidation zone. The supergene epigenetic ore-forming processes are induced by the interaction between the Earth's sedimentary cover and hydrosphere. Sedimentary rocks themselves commonly serve as a source of ore materials. The ore deposition zones on geochemical barriers and ore material source are often located significantly apart from each other. The trend of these processes is determined by the position of ore-bearing depressions in large tectonic blocks.