When talking about the formation of sedimentary rocks, it must be taken into account that many of them have thousands of years in which they have been modified and formed, some of them even house fossils. According to the way in which they have been formed, several types of sedimentary rocks are distinguished:
Explanation:
Detrital rocks: these types of sedimentary rocks have been composed over time by the accumulation of surpluses from the erosion of hillsides or large rocky units. Depending on the size of their clasts, that is to say, of the particles that have formed them, they can be differentiated between clusters, sandstones and clay rocks.
Organogenic rocks: those sedimentary rocks that have been formed with the remains of living beings. Two types are distinguished within organogenic sedimentary rocks according to their material:
Formed by biomineralization processes: composed from skeletons of living beings. It is the most abundant type.
Organic rocks: their formation is due to organic parts, that is, of the cellular matter from living beings. Although this type of organogenic sedimentary rock is less abundant than the other, the whole group is often called "organic rocks."
Chemical rocks: these sedimentary rocks have been formed due to the deposition of substances dissolved by chemical processes. An example of the formation of these rocks is the evaporation of seawater leaving salt that has to be accumulated by supersaturation, that is, by mineral accumulation. They are also called chemical precipitation rocks.
Margas: Many scientists do not consider them a separate type of sedimentary rock because it is a mixture formed by the accumulation of detritic and chemical or biochemical remains, that is, sediments from one of the three previous groups. Loamy rocks are formed by calcite and clay, the former being more predominant, which gives it a whitish appearance.
