Sedimentary rocks are a type of rock that are formed by the deposit of minerals into the ground that form into layers and harden over years and band together to form rocks. There are three main classification groups to identify sedimentary rocks are inorganic, chemical, and organic.
Inorganic Sedimentary Rocks
Inorganic rocks are sedimentary rocks that are made of other fragments that are caused by weathering (also know as clastic) . Inorganic sedimentary rocks are classified according to grain size, and are formed by composition and cementation. They are compositioned and cemented of other fragments of rocks when they are deposited into horizontal layers usually by running water entering calm water carrying the rocks and are put into the horizontal layers of rocks known as beds or strata.
Organic Sedimentary Rocks
Organic sedimentary rocks are formed from the remains of once living things, and they are referred to as "bioclastic". When the fossilized part of an animal or a shell becomes a rock, it is known as an organic sedimentary rock and is the result of when fossils come together and become cemented into this rock. Most of the fossils in the rocks are made of calcite, so when these rocks are formed together they most likely create rocks known as limestone.
Chemical Sedimentary Rocks
Chemical sedimentary rocks are rocks that are not made from sediments but rocks that have mineral crystals formed from elements that are dissolved in water. If enough water evaporates, and they do not all fit and some form crystals of minerals such as halite, gypsum, and calcite.
Where they are found
Sedimentary rocks are found all over the U.S.