The different groups of sediments could have been deposited through wind, water, ice, and/or gravity at different intervals of time and compacted on top of each other, until they create a sedimentary rock that has several different types of sediments (possibly from different rock types) in the form of layers.

Why do depositions often look layered? Sedimentary rocks have layers because of different depositions of sediments (small broken pieces of rocks) over time. These are your “sediments”. You get a large clear boc, and dump in all of your dirt.

Layered rocks form when particles settle from water or air. Steno’s Law of Original Horizontality states that most sediments, when originally formed, were laid down horizontally. Rock layers are also called strata (the plural form of the Latin word stratum), and stratigraphy is the science of strata.