Petrified Tree in Pine Mountain State Resort Park EarthCache

 

 

The two major types of fossils are body fossils and trace fossils.  Interestingly both are the remains of living organisms.  Body fossils replicate the body structure of the organism, where as trace fossils reveal the activities of these organisms.

 

The process of fossilization is called taphonomy.  There are three processes of taphonomy.  The first process is the death of the organism. The next process is the burial of the organism.  This process can include body decay related to natural elements such as wind, water, or the attack from predators.  The last process occurs after the organism's body is buried.  

 

There are several factors that can affect  fossilization. Body construction is one factor such as hard or soft body parts.  The environment is another factor.  The surrounding environmental conditions may contribute to rapid burial and preservation. The body may also be exposed to elements of erosion. We cannot forget that predators may also destroy the body before it is preserved.

 

 

There are many ways that fossils can be formed.  They include permineralization, freezing, compression, and entrapment by amber.  Most methods of fossilization include rapid burial which eliminates the effects of predators and erosion.  The process of rapid burial allows for preservation of the body or trace evidence.  

 

The major method that contributes to fossilization is permineralization.  Permineralization involves the hardening of minerals that have entered the small pores and cavities of dead organisms.  Water containing minerals is known as hard water.  As the hard water enters the pores, the minerals are deposited.  Under high pressures, it becomes solid.

 

The next step is that natural molds and casts form when hard parts are buried in sediment.  This leaves behind an impression of its shape.  Shells are an excellent example of molds and casts.  If the interior of the shell is filled with sediment and it hardens, then and internal mold would be created.  

 

 

The environment is crucial to fossilization. Areas in which there is a high rate of sediment deposited is the best environment because of the presence of minerals as well as the increase in pressure.

 

It should also be noted that the environment can also affect where the fossil is located. For example, water sources can carry a body away before it has had a chance to decay.  Conversely, drier environments are more vulnerable to the effects of erosion.  Therefore, it is more difficult to preserve the organism before it decays.

 

 

Body and trace fossils are most often located in sedimentary rocks.  The locations of major sediment deposits are found at the mouths of rivers or at the bottom of the sea and lake beds.  It makes sense that rock layers are formed with the oldest being at the bottom and the youngest at the top.  From this information we can learn about Earth's history from fossils.

 

Interestingly, fossils can also be found in unusual places like inside an amber or tar pit. Furthermore, under the right conditions fossils may be found in many places world wide.

 

 

Although there is much to learn from fossils, it is not an all inclusive record.  This is simply because not all organisms possess the correct properties that allow for fossilization. We should note that some organisms decay before the process for fossilization can occur.  We should further note that organisms that live on land as well as have soft body parts are less likely to fossilize than those organisms that live in water or have hard body parts.  We then must understand that the fossil record is only a piece of our rich Earth's history.

 

 

The word "petrified" is derived from Greek. The root petro means "rock" or "stone". Therefore, the translation is wood turned into stone.  Petrified wood describes a special type of fossilized remains of terrestrial vegetation.  Fossilization of a tree completely into stone occurs by the process of permineralization. While keeping the original structure of the tree, all the organic materials have been replaced with minerals, such as silicate.

 

Petrified wood impressions are unlike other types of fossils in that they retain a three dimensional representation of the original tree body.  The process of petrification occurs underground when the tree became covered with sediment.  It is preserved because there is a lack of oxygen.  Over time mineral filled water flows through the sediment and deposits minerals in the plant's cell.  As the tree begins to decay, a stone mold forms.  

 

During the petrification process, elements of manganese, iron, and copper found in the water and mud produce a variety of colors. It is noted that petrified wood can preserve the original structure down to a microscopic level.

 

 

According to nearby educational signage, "About 300 million years ago, during the Pennsylvania period of geologic time, a stately tree growing in this area died and became buried in sediments. As time passed, the plant material died and was carried away by water. The resulting cavity became filled with fine grains of sand consolidated into rock this cast of the original tree was formed. This fossil is a type of lycopod. The tree sized members of this group were among the largest plants growing in the coal-producing swamps which once flourished here."

 

In summary petrified wood is a fossil in which organic remains have been replaced by minerals that turn into stone.  In general, the fallen tree is buried in an environment that is free of oxygen.  This environment preserves the original plant structure and appearance.  Environmental conditions include a mineral rich water source that comes into contact with the tree.  The organic plant structure is replaced with minerals resulting in the basic structure being replaced by stone.

 

www.acad.carleton.edu

www.geology.com

www.wikipedia.org/petrified_wood

 

 

 

Kentucky State Parks Permit #15827PM05