Fossils

Fossils are the preserved remains or traces of once living organisms. Most sedimentary rocks like limestone and shale contain fossils due to when the fragments settle on a layer of sediment and when more layers lay on top of the fragment and the sediment turns into sedimentary rocks. Fossils can also be used to detemine the history and age of rocks in which they where formed. Fossil fuel is made out of living organisims like plant roots and animal skeleton.

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