Ash-covered forest gives glimpse of a past hundreds of millions of years old

Wednesday, 22 February 2012 12:17

News & Events - Engineering News

Over the centuries, historians managed to piece together a great deal of the truth about the Roman Empire through records and the scattered, incomplete archaeological sites remaining in Europe. But no one discovery proved as important in understanding that era than the uncovering of the city of Pompeii, buried in the ashes of Mount Vesuvias in 79 A.D.

Now Penn News reports that researchers led by University of Pennsylvania paleoecologist Hermann Pfefferkorn hope to make the same strides in the understanding of ancient ecosystems with the discovery of a nearly 300-million-year-old fossilized forest, found near Wuda, China, in the northern autonomous region of Inner Mongolia. At that age, the forest is from the very beginning of the Permian age when the world's landmasses were still condensing into the supercontinent known as Pangea.

Like Pompeii, this forest was buried in ash by a volcanic eruption estimated to have occurred around 100 miles from its location at the time. While a nearby eruption would destroy much of the vegetation in the immediate area, the waves of ash that covered the surrounding areas actually had the opposition effect, tearing down trees with their weight but ultimately burying much of the forest largely intact.

"It’s marvelously preserved," Pfefferkorn told Penn News. "We can stand there and find a branch with the leaves attached, and then we find the next branch and the next branch and the next branch. And then we find the stump from the same tree. That’s really exciting."

Nature notes that studying ancient ecosystems can often prove incredibly difficult, because the fossils that researchers use to investigate them are often few and far between. Plants found in the same region might have grown millions of years apart, while those from the same era might not have been a part of the same ecosystem. Some events, such as floods, can lead to the mass fossilization of large amounts of plant matter. But floods tend to bring in plants and other organisms from the source of the water while carrying away a large amount of local plant life.

The Daily Mail notes that the specific circumstances of the forest aided researchers in another way. The forest at the time was in a marshy coastal area, covered in peat and perfectly suited to the formation of coal. Huge swaths of the surrounding countryside have been dug up by coal mining in the region, providing access to deep excavations large enough to reasonably examine the entire ecosystem.

Pfefferkorn noted that the site has provided some surprises, with some plants growing side-by-side that had been previously identified but never associated with each other.

"This is now the baseline," Pfefferkorn said. "Any other finds, which are normally much less complete, have to be evaluated based on what we determined here."

Notably, the forest is not necessarily a definitive example of the forests of its era. Many of those forests most similar to it had dried out with the shift from scattered landmasses to a single continent as islands suddenly found themselves surrounded by land. Nevertheless, the forest could serve as a point of comparison for many older ecosystems.

"It’s like Pompeii: Pompeii gives us deep insight into Roman culture, but it doesn’t say anything about Roman history in and of itself," Pfefferkorn explained. "But on the other hand, it elucidates the time before and the time after. This finding is similar. It’s a time capsule and therefore it allows us now to interpret what happened before or after much better."