oksidasjonsbelt

An oxidation belt is a zone within a mineral deposit where sulfide minerals have been oxidized. This process typically occurs near the Earth's surface where oxygenated groundwater or atmospheric oxygen can interact with the sulfide minerals. The oxidation can transform primary sulfide minerals into secondary oxidized minerals such as oxides, sulfates, and carbonates. This alteration process can significantly change the mineralogy, geochemistry, and physical properties of the ore body.

The formation of an oxidation belt is influenced by several factors, including the depth of oxidation, the climate, the presence of water, and the type of sulfide minerals present. In arid climates, oxidation may extend deeper, while in humid regions, the oxidation zone might be shallower. The extent of oxidation is also dependent on the permeability of the rock, allowing for easier access of oxidizing agents. Different sulfide minerals react at different rates; for example, pyrite is readily oxidized, while chalcopyrite may be more resistant.

The minerals found within an oxidation belt can include native copper, malachite, azurite, goethite, and various sulfates. These secondary minerals can sometimes form economic concentrations themselves, especially in the case of supergene enrichment where dissolved metals from the oxidized zone are reprecipitated at a lower level. Understanding the characteristics of oxidation belts is crucial in mineral exploration and mining, as it affects ore grade, metallurgical recovery, and the stability of mine openings. Geochemical and mineralogical studies of the oxidation zone can provide valuable clues about the original mineralizing processes and the subsequent geological history of the deposit.