Walls still can’t talk, but an Ohio U. professor used a 7,000-year-old stalagmite to prove rocks can tell stories.

Gregory Springer, associate professor of geological sciences, along with Harry Rowe, a professor of geology at the U. Texas at Arlington, made a discovery about early Native American life during a study originally intended to reconstruct climate patterns. Native Americans had a greater impact on carbon emissions than scientists previously thought, Springer said. The findings were published in the journal The Holocene.

The study’s participants examined a stalagmite that had grown in Buckeye Creek Cave in southern West Virginia. The stalagmite’s carbon levels indicated a major drought about 2,000 years ago – a climate pattern that had already been disproved by previous studies, Springer said. Springer and his colleagues surmised that if the changed carbon levels were not caused by climate change, they must have been caused by human activity.

A group of archaeologists conducting a study in a nearby cave had found indications that Native Americans had lived in the area, so Springer began to look for connections and concluded that Native Americans had influenced carbon levels by cutting down and burning trees. One explanation, he said, is Native Americans eliminated trees that didn’t provide food, such as acorns and hickory nuts.

“If (Native Americans) were living in that cave, they almost certainly would have been doing something to the forest above,” Springer said. “If they changed vegetation in major ways – by burning trees, for instance – it would show in the stalagmite as we saw it.”

The study indicated the Native Americans of the time had a greater impact on atmospheric carbon levels than scientists would have expected from a group living before the Industrial Revolution.

However, the scientific implication goes further, Rowe said.

“What we’re really talking about is that the (Native Americans) left their mark on the landscape,” Rowe said. “We think the carbon dioxide levels (left by Native Americans) was a small amount compared to what was already there.”

Michael Manga, a professor of Earth and Planetary Science at the U. California-Berkeley, said the study’s significance can be measured in the imprint the Native Americans left.

“We all leave a footprint,” he said. “And the Native Americans left one that is big enough to show up in the geologic record.”