Sedimentary rocks is formed when layers of the eroding Earth are put on top of one another. These layers are pressed down together more and more through time. When the rock is getting pressed together, the bottom layers start turning into rock. Scientists have four ways to classify sedimentary rocks. They are erosion, deposition, compaction, and cementation. The three types of sedimentary rocks are clastic, chemical and organic.
Uses: Sedimentary rock can be used for a lot of things, like buildings, to make brick, roads, glass making, chalk, etc.