Map Of gypsum deposits in northern Ohio, black squares show the location of deposits, from "Geography of Ohio", 1923 Gypsum is used in a wide variety of apps: Salt Flats: Gypsum is a common component of salt flats, which are expansive, flat spots using a salt crust to the surface https://www.propanraya.com/id/produk/eco-gypsum-ee-4050