Introduction to the petrified wood group: The petrified wood in the park is basically coniferous trees, which were formed between 140 and 170 million years ago. Due to volcanic eruptions and sudden stratigraphic fractures, the trees were buried underground and were exposed to oxygen and high temperatures. Under the environment, over a long period of time, the organic matter in the wood was replaced by siliceous minerals in the groundwater, and through crustal movement such as stratigraphic uplift, these petrified wood were pushed out of the ground, forming petrified wood.