A fossil is the prehistoric remains of a plant or an animal. Fossils are usually are kept at their best when they are buried under many layers of sand and mud. Under the great pressure from the ground, the sand and the mud become sedimentary rock. The minerals combine forming a mould of the plant or animal under the ground. A fossil can be a trace fossil or a body fossil. A body fossil is what actual organic material from a creature or plant (like a bone). Trace fossils are signs of plants and animal activity that have been preserved in rock. For example, dinosaur tracks, trails and dung are all trace fossils. A body fossil is usually composed of bones of an animal. Preservation of the “soft” tissue of a body is rare especially over long periods of time. Most body fossils are made when an animal dies and falls, or is washed into a steam, and is covered with mud. In a few cases, though, fossils have been preserved by freezing (as with mammoths in Siberia and Alaska) or when the animals have become stuck and died in a tar pit (such as the famous La Brea tar pit near Los Angeles, California). Sometimes a fossil is the result of a volcanic eruption. Ash and mud from the volcano can cover animals and plants killing them at the same time.
Geology is the study of the Earth, the materials of which it is made, the structure of those materials, and the processes acting upon them. It is also the study of organisms that have inhabited our planet. An important part of geology is the study of how Earths materials, structures, processes and organisms have changed over time. Fossils are linked to geology because, it is the study on how the world has build up over the years and fossils are animals and plants from over the years. They have changed over time because they have become smaller and form in different ways like freezing and volcanic eruptions. Over the years fossils have told us about life forms we had no idea about and is proved with the fossils or