Author: JÃ¶rg Scherber
Content by courtesy of : Jörg Scherber`s website
There are several petrified forests located at Wyoming. Three main collecting areas are well known.
a) the Big Sandy Reservoir located north of Farson
b) the region around Oregon Buttes
c) the legendary Blue Forest
Eden Valley petrified wood was formed from plants living about 58 million years ago (EozÃ¤n Geologic age). The rock exhibits features not found in fossil wood anywhere else in the world. The fossil wood is known for the light blue agate surrounding many of the pieces.
The petrification process for this area involved shallow Â“algae growingÂ” lakes. In many cases for undetermined reasons the wood came to be in this water in its live condition before it had a chance to dry out. This wood became coated with algae which adhered to the surface making a cast or mold around the wood. Later the wood dried and shrunk in the mold made of algae. Over times these algae casts became part of a layered rock formation. Silicia-rich water solutions seeping through the rock then petrified the wood and filled in the spaces left between the dried wood and the hardened cast with blue agate, calcite and quarz.
As the agate coated the inside surface of the algae cast, perfect impressions of the bark were left in the agate. Because the petrification process seems to have been protected by the algae cast formation, unusually detailed representations of the wood have been preserved.
wood from the 'Blue Forest'
1.9 Blue Forest
(ca. 220 x 170 mm)