Every soil<span> originally formed from parent material: a deposit at the Earth's surface. The material could </span>have<span> been bedrock that weathered in place or smaller materials carried by flooding rivers, moving glaciers, or blowing winds.</span>
2 or more different atoms are combined in definite proportions in any compound.
First, preexisting rocks must weather/erode, forming the sediment that will eventually form the sedimentary rock. Then, that sediment must settle someplace, and over a long period of time, pressure begins to build. This causes the sediments to become compacted. After a long period of time (and a lot of pressure), the sediments cement together and form a sedimentary rock. In a nutshell, sedimentary rocks form through compaction, cementation, and eventually... lithification.
Hope that helped! <span />
