− | Anhydrite is the anhydrous form of [[gypsum]], CaSO<sub>4</sub>, to which it readily transforms with the introduction of water. Gypsum is transform to anhydrite at depth because of the increase in temperature. Anhydrite beds are often seals for traps. | + | Anhydrite is the anhydrous form of [[gypsum]], CaSO<sub>4</sub>, to which it readily transforms with the introduction of water. Gypsum is transformed to anhydrite at depth because of the increase in temperature. Anhydrite beds are often seals for traps. |