Carbonatization

a process of change occurring in rocks leading to the formation of carbonates of calcium, magnesium, iron, and other metals. Basic intrusive and particularly extrusive rocks most frequently undergo carbonatization under the action of hydrothermal solutions rich in carbon dioxide. Cases of strong carbonatization of granodiorites are known to occur in connection with processes causing the formation of gold and lead-zinc ore deposits. The changes that take place in the carbonate rocks themselves should also be included in the carbonatization processes, both in the diagenetic stage and in the subsequent stagesof transformation, particularly in cases of hydrothermal meta-morphism of carbonate rocks related to magmatic intrusions.Sometimes carbonatization of ultrabasic rocks is accompaniedby the formation of talc and fuchsite (chrome mica) and istherefore referred to as platy venitization. In some regions, car-bonatization serves as a prospecting indicator of certain mineraldeposits.