Where can sedimentary rock be found in the Earth's crust?

Sedimentary rock forms from the process of lithification, during which sediment material is compressed by “loading”, or the pressure or rock or sediment on top of it, and subsequently cemented when minerals in groundwater crystallize between the sediments, binding them together. read more

Sedimentary rocks are found covering a majority of the Earth's upper crust. Formed from the deposition of mud and sand that is buried and compressed to form solid rock, sedimentary rocks usually begin their life underwater, rising to the Earth's surface as the waters dry up. read more

Oceanic crust, being so thin, is a very small fraction of the Earth -- about 0.1 percent -- but its life cycle serves to separate the contents of the upper mantle into a heavy residue and a lighter set of basaltic rocks. read more