A brief discussion of the multitude of biased events which limit the possibilities of fossilization will then be followed by the basic types of fossils that may be formed.
Carbonization is one form of fossilization and is typical for such organisms as plants and insects.
These fossils are a coal black film formed when the volatile organic compounds disperse from the decomposing organism and end up leaving a thin residue of carbon. Permineralization is a second type of fossil formed. The soft tissue of the organism decay away and the remaining hard parts are flooded with ground water. Which ever mineral is present precipitates out and fills the pores of the long gone organism. Dissolution and replacement is a third type of fossilization and can be a step wise progression from permineralization.