The petrified forest was formed in connection with the eruption of the Zeisigwald volcano in the lower Permian and dates back about 291 million years . The trees were uprooted or snapped off by the eruption and the amount of tephra , much like the trees caught in the 1980 eruption of Mount St. Helens . The trunks were then covered with hot tephra . In the following of years , the silicic acid included in the tephra ensured the fossilization of Permian plants , preserving them until today
1980 eruption of Mount St. Helens
1980 eruption of Mount St. Helens
Chemnitz petrified forest