Don''t be scared, your in Holdingford, MN, the heart of Lake Wobegon, where according to Garrison Keillor, "all the Women are strong, the Men are good looking, and the Children are above average,"
Here you will find one big, hard, heavy rock. Not one of your run-of-the-mill Erratic Boulders, it's a fossil really, and maybe the largest examples of PETRIFIED WOOD ever found in Minnesota.
"What is Petrified Wood?
Petrified wood is a fossil. It forms when plant material is buried by sediment and protected from decay due to oxygen and organisms. Then, groundwater rich in dissolved solids flows through the sediment, replacing the original plant material with silica, calcite, pyrite, or another inorganic material such as opal. The result is a fossil of the original woody material that often exhibits preserved details of the bark, wood, and cellular structures.
Some specimens of petrified wood are such accurate preservations that people do not realize they are fossils until they pick them up and are shocked by their weight. These specimens with near-perfect preservation are unusual; however, specimens that exhibit clearly recognizable bark and woody structures are very common."
From geology.com
"How does petrified wood form?
The most important cause of wood fossilization is the rapid burial of wood plant matter. This quick burial process creates an environment poor in oxygen and seals off bacteria and fungus that would cause decomposition. After this, two different processes can occur:
1 - The more recognizable process is when groundwater, full of minerals, flows through the overlying sediments and into the buried wood. As the water flows through the material, it deposits minerals picked up from the sediments. These mineral particles replace the organic matter but preserve all the textures and structures the wood had when it was still above ground. Some of these pieces will even show bark or tree rings!
2 - Another way wood can be fossilized is through the cast and mold process. After the wood is submerged, water flows through the sediment into the material, but instead of slowly replacing the internal structures of the wood, the wood is essentially dissolved away leaving a cavity called a mold. This cavity is then filled with minerals, like quartz, that preserve the exterior texture of the wood. This replacement is called a cast."
From gemstones.com
Logging Requirements - Message me A and B, while logging C.
A - In your own words:
- What colors do you find in the large fossil here?
- Do you observe any of the nature of the wood: bark, grain, growth rings, etc?
B - From the source quoted on this cache page, which process do you think formed this fossil?
1 - The mineral replacement process
or
2 - The "cast and mold" model
C - Please post a photo of yourself or a personal item with your log (not of THE log).