Sedimentary rocks are types of rock that are formed by the deposition and subsequent cementation of that material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles (detritus) to settle in place.
There are three different types of Sedimentary Rocks.
Inorganic sedimentary rocks such as breccia, conglomerate, sandstone, silt-stone, and shale are formed from mechanical weathering debris.
Chemical sedimentary rocks, such as rock salt, iron ore, chert, flint, some dolomites, and some lime-stones, form when dissolved materials precipitate from solution.
Organic sedimentary rocks such as coal, some dolomites, and some lime-stones, form from the accumulation of plant or animal debris.
Where these Rocks are Found.
Sedimentary rocks form when mud and sand are deposited in layers on the Earth's surface. The layers are deposited in many environments including oceans, rivers and deserts. These layers of sand and mud are later buried. The weight of overlying layers compresses the mud and sand to form solid rock.