Answer: Chemical sedimentary rocks.
Explanation: Those may be a type of sedimentary rocks called "chemical sedimentary rocks". This type of rock forms when mineral constituents in solution become supersaturated and inorganically precipitate. Formed by deposit of dissolved substances, were the largest volume corresponds to masses of salts accumulated by supersaturation of seawater. When seawater is stagnant, it begins to evaporate and dissolved minerals precipitate, this process gives rise to evaporites, for example gypsum and gem salt.