The right answer is the salts precipate out of solution.
There are two types of current evaporites:
* the evaporites of free water, coming from the evaporation of a body of water;
* capillary evaporites resulting from the precipitation of the salts of an intertitle brine in the pores of a sediment.
The formation of evaporites is favored by the arid climate and the confinement of the environment. Nevertheless temperate but very windy coastal areas are also the seat of a strong evaporation.
In the current salt marshes, the confinement of the body of water is accompanied by an intense biological activity: insect larvae, algae, bacteria.