They are mostly created underwater. Sediments make up sedimentary rock with materials such as mud, clay, sand, pebbles, and organisms that once lived there. These materials are worn down over the years by natural events such as wind, water, rain and snow. Imagine a road in winter when it begins to crack and wither. The sediments eventually end up in one place and pile up on top of each other. By looking at these rocks we have the opportunity to see into the past and understand what the world was like long ago. This is possible by observing the impressions made by different organisms and