Evaporite

An evaporite is a sedimentary rock or mineral deposit formed when evaporation concentrates dissolved salts until they precipitate. Common evaporites include gypsum, anhydrite, and halite.

Evaporation: The change of a liquid into vapor at its surface. Water loss concentrates dissolved ions until minerals can precipitate.
Solubility: The capacity of a substance to dissolve in a specified solvent under given conditions. Solubility determines when dissolved salts can begin forming evaporite minerals.
Salt dome: A body of salt that rises through overlying rock, often forming a dome-shaped structure. Buried evaporites can flow upward and create structures that trap hydrocarbons.
Messinian salinity crisis: A late Miocene episode when the Mediterranean Sea underwent major drawdown and extensive evaporite deposition. Its thick Mediterranean salt deposits record extreme restriction and evaporation.
Brine: Water containing a high concentration of dissolved salts. Evaporite minerals form as brines become progressively more concentrated.
Saturation (chemistry): A solution state in which it holds the maximum dissolved amount of a substance under specified conditions. Evaporite precipitation begins when brines become saturated or supersaturated.
Salt tectonics: The deformation and movement of underground salt under pressure and gravity. Thick evaporite layers deform readily and reshape sedimentary basins.
Zechstein: A Permian geological unit in northern Europe known for extensive evaporite deposits. Its cyclic salt and gypsum beds illustrate repeated marine flooding and evaporation.
Mineral precipitation: The formation of solid minerals from a solution when dissolved components become saturated. Evaporites accumulate when concentrated brines reach mineral saturation.
Closed basin: A drainage basin with no outlet to the ocean, where water leaves mainly through evaporation or seepage. Restricted drainage lets dissolved salts accumulate instead of washing away.

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