Deep-Earth Carbon Reveals New Details About the Origin of Life

Carbon deep beneath Earth's surface may have influenced the history of life on our world. Scientists have taken a closer look at this carbon and have learned a bit more about the vital role that this element played in the planet's formation.

For decades, scientists have had very little understanding of how carbon behaved deep below Earth's surface. That's why they decided to investigate a bit further using a model. This model revealed how much carbon and what types of carbon exist in fluids at 100 miles below Earth's surface.

"It is a very exciting possibility that these deep fluids might transport building blocks for life into the shallow Earth," said Dimitri Sverjensky, one of the researchers, in a news release. "This may be a key to the origin of life itself."

In this case, the researchers used the Deep Earth Water model to determine the chemical makeup of fluids in Earth's mantle, expelled from descending tectonic plates. Some of the fluids contained the expected carbon dioxide and methane. Others, though, contained dissolved organic carbon species including a vinegar-like acetic acid.

So that does this mean? The high concentrations of dissolved carbon species suggest that they help to ferry large amounts of carbon from the subduction zone into the overlying mantle wedge where they are likely to alter the mantle and affect the cycling of elements back into Earth's atmosphere.

That's not all the scientists found, though. It's possible that these mantle fluids with dissolved organic carbon species could be creating diamonds in a previously unknown way. Together, the new findings reveal a bit more about the planetary processes that helped shape our world. Not only that, but it reveals a bit more about the cycle of carbon.

The findings are published in the journal Nature Geoscience.