Wood fossilization is a group of processes where all organic material is replaced by minerals. Petrifaction process occurs underground when wood is buried under sediments. Wood is then preserved due to the lack of oxygen. Water with a high content of minerals filters through the sediments and deposits minerals into the cells of the plant. Consequently, when minerals decompose, some kind of a rock mold is form in their place. Trees in this place have to be unearthed from an approximate depth of 2 to 6 meters.
