Organic products from ancient life are an integral part of the Earth’s resources, offering scientists a more accurate picture of ancient life-forms. One key to ancient life comes in the form of petrified matter. Petrifaction is a process that slowly turns the remains of a living object into stone. In this process, minerals seep into a mass of organic matter. After the organic matter has been replaced, a mineral version of the living object is left. Petrifaction often occurs in trees that are found adjacent to rivers, floodable areas, and volcanoes, which provide the mud or ash that initially covers the organic matter. Some pieces of petrified wood retain the original cellular structure of the wood and the grain can be easily seen. Today, it is feasible to petrify wood in a simple laboratory process.
Fossils are another way that ancient life is preserved. Most fossils include an animal’s hard parts, such as teeth and bones. One type of fossil, called a trace fossil, may also include eggs, tooth marks, contents of the guts, and fossil excrement. Some products from ancient life offer us more than scientific knowledge. One such product is coal, a solid fuel of plant origin. It develops over millions of years, during which swamp vegetation is submerged in water, depleted of oxygen, and covered by layers and layers of sand and mud. These overlapping layers settle with the Earth’s movements and are compressed over time.