Evaporiteja

Evaporiteja refers to evaporite minerals and rocks formed when saline waters become highly concentrated and transitional basins or coastal lagoons dry out, causing dissolved minerals to precipitate. The process occurs most readily in arid to semi-arid climates or in restricted basins where water input is limited and evaporation rates are high. Over time, successive mineral precipitation can build up layered evaporite deposits.

The most common evaporite minerals are halite (rock salt), gypsum and its anhydrous form, calcium sulfate, and various potash- and magnesium-rich salts such as sylvite (potassium chloride) and carnallite. In many deposits, gypsum or anhydrite precedes halite, followed by salts of potassium and magnesium. Some evaporite suites also include borates, nitrates, and other soluble minerals formed from brines with distinctive chemical compositions. Evaporite rocks are typically distinct from clastic sediments and can remain coherent after lithification, forming expansive rock units.

Geological significance and economic importance are substantial. Evaporites preserve records of past climate, sea level, and basin hydrology, helping reconstruct paleoenvironmental conditions. Economically important products include rock salt for road de-icing and chemical use, gypsum for cement and plaster, potash fertilizers, and borates. In some basins, brines hosting lithium and other elements are developed from evaporitic sequences.

Global distribution covers arid and semi-arid regions with restricted basins, both in ancient and active sedimentary environments. Evaporite deposits commonly form in intracontinental rifts, foreland basins, and restricted marine settings, and their formation is often linked to tectonic and climatic factors that reduce water exchange with open oceans. Evaporites are relatively soluble and can be altered by diagenesis or dissolution, influencing landscape and groundwater systems.