Hydrogenous sediments are produced when dissolved minerals solidify by chemically reacting with seawater. Common examples of hydrogenous sediment are evaporites, manganese nodules and oolites.
Marine sediments are accretions of loose materials transported and deposited on the ocean floor. The different types of marine sediments include hydrogenous, lithogenous, cosmogenous and biogenous. Hydrogenous sediments are valued for their economic importance.
Sedimentation of hydrogenous components may occur where they are deposited, rather than having been transported to the ocean floor. Evaporites are created when ocean water evaporates and crystallizes, which typically occurs in dry, shallow-water aquatic areas.
Halites, gypsum and calcium are primary examples of evaporites. Manganese nodules are mainly composed of iron and manganese oxide, nickel, chromium and cobalt. Oolites are formed from the precipitation of calcium carbonate in seawater.