Transcript Petrified Wood - Oregon State University

Petrified Wood
By: Jen Osburn &
Hannah Pugh
Some Questions to Answer…
•What is petrified wood?
•How is it formed?
•Why are there multiple colors?
•Where can this wood be found?
•What has petrified wood been used for?
•What are some interesting properties of petrified wood?
•Are there any interesting stories associated with it?
What is Petrified Wood?
• A fossil in which all of the
organic components
of wood have been replaced
by minerals
• The original structure of the
wood is normally preserved
• Sometimes the individual
structure of cells can be
distinguished
• Tree rings can be observed on many pieces
• At the microscopic level, many tissues of the wood
can be identified
The Petrification Process
STEP 1:
Wood gets
buried in
sediment. This
usually occurs
due to volcanic
eruptions,
mudslides, or
other natural
disasters.
STEP 2:
Water rich in
minerals flows
through the
sediment.
STEP 3:
The minerals replace
the wood’s cells and
organic materials
with stone over the
course of many
years.
What is Involved?
•Preservation of the “wood” can be attributed to a lack of
oxygen.
•Most of the minerals involved in the process are
silicates.
•The structure of the cells of the wood can be preserved
so well by that the features can be observed in detail at a
microscopic level.
•The minerals take the place of the wood’s lignin and
cellulose as they decay.
Colors
Different elements in the minerals yield different
colors in the new fossilized wood.
Carbon: Black
Cobalt: Green/Blue
Chromium: Green/Blue
Copper: Green/Blue
Iron Oxides: Red, Brown, Yellow
Manganese: Pink/Orange
Manganese Oxides: Black
Locations
The world is constantly changing, most of the land
mass at one time was covered in tropical forests, so
petrified wood can be found almost anywhere.
The Best Locations…
•Argentina
•Canadian Badlands
•Czech Republic
•Greece
•Libya
•USA
•Australia
•India
What Can It Be Used For?
Paper weight anyone?
Interesting Properties
•On the Mohs Hardness Scale, petrified wood is rated
with a 7, the same as quartz.
•Petrified wood is the state gem of Washington.
•Petrified wood generally makes a better pet rock
than regular rocks.
•Petrified wood is the official state fossil of Arizona.
•Petrified wood can weigh thousands of pounds.
Folklore
Many myths and fairy tales have some
mention of the petrification process.
•The story of Medusa
•Basilisks
•Children’s games
•Various fairy tales
Can It Be Made in a Lab?
A lab in the state of Washington has successfully
created artificial petrified wood.
References
•http://en.wikipedia.org/wiki/Petrified_wood
•http://www.scienceviews.com/parks/treestostone.html
•http://www.desertusa.com/mag00/jan/papr/rock.html
•http://en.wikipedia.org/wiki/Petrifaction