<div>The process of the formation of sedimentary rocks consists of the transformation of sediments, loose material formed by particles which are not joined together, into rocks, solids and compacts. This process is know as lithification, a word which means "transformation into rock".</div>
<div>There are various important changes involved in this transformation into stone :</div><div>- Compaction</div><div>- Cementation</div>
<div>Compaction: Is due to the weight of the materials which are at the bottom are subject to more and more weight as more sediments are deposited. In this way, the water and air are lost from between the particles, meaning that the acumulation of sediments becomes more and more compact.</div>
<div>Cementation: Consists of precipitation of various mineral compounds that are between the particles of the sediments. This precipitation forms a cement which joins the particles together and decreases the porosity of the sediment.</div>