Processes of Fossilization

ReplacementReplacement fossilization is similar to Permineralization in that a foreign mineral assumes the shape of the organic material. However it is also similar to Mold fossilization in that the organic matter is already deteriorated. The result is a foreign mineral being molded into the shape of the original organism. Some of the most interesting examples involve metals such as iron pyrite replacing the form of an invertebrates shell mold.

ReturnHomeWrongRemember, Replacement means that the original mass deteriorated to nothing, and a foreign mineral merely filled the leftover mold.

Try AgainPermineralizationPermineralization occurs when organic material, such as bones or wood, absorb and hold minerals before decaying themselves. This results in a drastically different and more stable composition of fossil than the original organic material. These are the kinds of fossils people are most familiar with, largely due to the fact that most dinosaur bones are a result of Permineralization.Petrified Wood is another great example of Permineralization.

Return HomeTypes of Fossilization

PermineralizationMoldReplacementRecrystallizationCarbonizationAfter millions of years, most organic matter is either destroyed or broken. While there are forms of fossilization that will provide unaltered organic material, most fossils found are changed from their original composition. In this presentation, you will be familiarized with these Processes of Fossilization.

Desiccation

Amber

Ready to test yourself?MoldA mold occurs when organic material is buried by sediment. Eventually, the organic material decays, leaving a trace outline of the original organism. In this manner, no organic material remains. These also include fossils of footprints or of textures from things such as feathers or leaves.Sometimes sediment inside a clam will fossilize, giving an imprint of the clams insides. These are called Steinkerns.

ReturnHomeWrongRemember, fossils that are preserved by desiccation still have much of their skin and inner organs intact. The fossil shown consists only of bones and some carbonized hair.

Try AgainRecrystallizationRecrystallization occurs when organic material isnt chemically stable enough after deposition to maintain its composition. This is most often found amongst invertebrate shells, which will change from aragonite to calcite.

Return HomeCarbonizationCarbonization occurs when enough pressure is placed upon organic material that the carbon is left behind in the rock. Examples are characteristically black and in the shape of the animal that was deposited.

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Desiccation

Desiccation occurs when an animal dies in extremely dry and arid locations, such as deserts or some caves. Essentially, these conditions create an aseptic environment, where it is highly unlikely that it will be able to decay. These fossils are very rare, due to the fact that they require that the remains be undisturbed by scavengers and that the environmental factors leading to desiccation remain constant. Desiccation is almost identical to mummification, although it is conducted by natural conditions and are typically from further back in time.

Return HomeWhich two processes formed this fossil?

A. Carbonization and RecrystallizationB. Permineralization and MoldC. Permineralization and CarbonizationD. Replacement and MoldThis animals bones still have traces of its original organic matter. Also, markings around its body indicate that it at one point had fur.E. Desiccation and Carbonizationnull66010.055