On display near the north entrance of the Liberal Library is a large specimen of petrified wood. As an Earthcache there is not a container to find, instead we have the opportunity to learn about petrified wood. A parking waypoint is provided. The Earthcache is wheelchair accessible.
After completing this Earthcache you will have a better understanding of:
- How wood is turned into a stone fossil
- How certain elements effect the fossil
- How much does petrified wood weigh
Definition
Petrified Wood: A special type of fossilized remains of terrestrial vegetation. From the Greek root petro meaning "rock" or "stone"; literally means "wood turned into stone".
How does wood turn to stone?
Wood must be covered with volcanic ash or lava, volcanic mud-flows, sediments in lakes and swamps, or material washed in by violent floods. The wood is initially preserved due to the lack of oxygen which inhibits decomposition. Mineral laden water flowing through the covered material deposits in the plant's cells. Through a complex chemical process involving heat and pH balance, the minerals (typically Silica) replace the organic material and individual plant cells. The result is a fossil of the original woody material that often exhibits preserved details of the bark, wood, rings, and cellular structures. The process can take millions of years.
Example of Petrified Wood below
How do elements effect the fossil?
Elements such as copper, iron, manganese in the water / mud during the petrification process give petrified wood a variety of color ranges. Pure quartz crystals are colorless, but when contaminants are added to the process the crystals take on yellow, red, and other tints.
Following is a list of contaminating elements and related color hues:
- Carbon – black
- Chromium – green/blue
- Cobalt – green/blue
- Copper – green/blue
- Iron oxides – red, brown, and yellow
- Manganese – pink/orange
- Manganese Oxides – blackish/yellow
How much does petrified wood weigh?
Petrified wood can be very brittle and shatter like glass. However, it is as strong as steel. Petrified wood rates between 7 and 8 on Mohs Hardness Scale, with talc at 1 and diamonds at 10. It is also very heavy and weighs between 160-200 pounds per cubic foot.
Sources
wikipedia.org/petrified_wood
geology.com/petrified-wood
nps.gov/pefo/faqs
To qualify for this Earthcache send me an email or message via my geocaching profile with the answers to the following questions. Do not post the answers in your log. Photos are encouraged!
- In your own words, define petrified wood.
- What color is the petrified wood and what element may have caused it?
- Estimate the height and circumference of the specimen. About how much does it weigh?
You may go ahead and claim "found it" once you have come to ground zero, If I don't receive the information required from you within 24 hours, I will delete your "found it" log.
