How Fossils are Formed

How Fossils Are Formed

There are several processes through which the fossils of plants and animals were formed. However it was and still is rare that the right series of circumstances took place that were necessary for a fossil to form. More often than not scavengers and weather took care of the remains before there was time for a fossil to form. To get to fossil form the remains of the plant or animals had to be perfectly preserved by burial in mud of sediment, a rare occurance for most animals.

The first step in the formation of any fossil is that the plant or animal to be fossilized must die, preferably in water, or near enough to water that it will fall into the water soon after death. Water acts as an insulator against the elements that will lead to the decomposition of the animal. The soft parts of the organism are consumed, leaving only the bones and teeth behind.

Over time the remains are buried by sediments. The faster the rate that the remains are buried the more likely it is that a fossil will form. Animals that are caught in landslides and fall into pits of mud usually become well preserved fossils because of how quickly they are covered in the sediment. The type of sediment also plays a role in the formation of a fossil. If the sediment is made of smaller fine grained particles that fossil is likely to show up in much more detail.

The next step in the formation of a fossil is called permineralization. The sediment continues to pile up on itself, compacting the lower layers and increasing the pressure placed on them. Eventually that pressure will turn the sediment that holds the animal remains into stone. The next step, called uplift, occurs as the continental plates push into each other and push buried rock up toward the surface. Often this means that rocks that were once ocean floor are pushed up to become hills and mountains on dry land. If this happens to the place where a fossil has now formed it is now on dry land, but buried under lots of layers of rock.

Now that the fossil had been formed and preserved for hundreds of years the only other step necessary before it can be found is the process of erosion. The natural elements play a huge role in this part. Rain and wind along with the natural freezing and thawing help to force fossils out of the ground and up to the surface where they can be found. Even earthquakes can help with this process.