Today at Brown

Stephen Parman became a geologist in the true scientific mode — after eliminating the alternatives.

When he enrolled as an undergraduate at Harvard, Parman was wrestling with whether he wanted to be a scientist or a writer. He had enjoyed science ever since being awed by a middle school geology teacher in Delaware, where he grew up. Then again, Parman loved to write, and now, he had gotten his chance, having been accepted into the fiction-writing program at Harvard.

“I hated it,” Parman recalled, noting in particular his dislike of the readings he and his classmates had to give before class. “It was like going to the dentist every week.”

Decision made, Parman launched himself into science, meeting his German wife along the way (he cleaned her laboratory equipment). Now, the 36-year-old father of two joins the Department of Geological Sciences this fall as an assistant professor.

Parman has been intrigued by the geologic history and evolution of the early Earth (what he calls the “Earth’s deep past”) and the mystery over exactly what was going on deep inside the planet during the first 2 billion years of its existence, an era from which few clues remain.

To gain more insights, Parman simulates the conditions deep inside the early Earth by conducting laboratory experiments at high pressure and at high temperatures, a branch of science known as experimental petrology.

“These processes leave chemical traces, and some of these traces are left on the surface of the Earth,” he explained. “But we don’t know what they mean. We need to create that process in the lab, to look for the chemical changes they produce and match them with what we see in nature.”

One enduring debate that Parman has investigated revolves around convection in the Earth’s mantle. Geophysicists, as Parman explained it, mostly believe convection cells span the entire mantle; geochemists generally disagree, arguing convection is confined to certain layers. So Parman studied how helium behaved during mantle melting, a key piece of geochemical evidence for the layered mantle convection theory. In a paper published in Nature, he showed that the isotopes don’t require layered convection; rather, they are consistent with the whole mantle convection theory.

He wrote two more papers in Nature that concluded, among other findings, that the Earth’s crust is created through intermittent bursts of mantle melting. This fall, he will travel to the Klamath Mountains in California to look for evidence of those bursts.