-A window into study of vegetation and climatic change throughout geological history

Endless geo-historical changes are closely related to the genesis and evolution of life. During the late Paleozoic and Mesozoic (about 150~300 million years ago) eras, the terrene was covered by flourishing plants and gestated rich fern and gymnosperm forests. Especially during the late Jurassic (about 150 million years ago) period, high and flourishing gymnosperms were in fashion for a period so that they became the advanced terraneous plants dominating the earth.

However, due to the effect of volcanic eruptions, forest fires, large-scale transgression and regression, erosion from rainstorms and floods, large-area mud-rock flow and such geological movements induced by tectonic movements, part of the forests were buried in the underground stratums so that trees were isolated from the air for a long time and formed petrified wood (commonly called "ancient petrified tree"), with the botanic stems and trunks as the main forms through a very long petrifaction. So-called petrifaction mainly means silification. In a strict sense, the petrified wood can be divided into mineralized-petrified wood, carbonized-petrified wood and other types. No matter what type the petrified wood is, it pertains to the effect of silicon dioxide (SiO^₂).