FSU geochemist challenges key theory regarding Earth's formation

Munir Humayun with an Inductively Coupled Plasma Mass Spectrometer in the new Plasma Analytical Facility in the Geochemistry section of the National High Magnetic Field Laboratory. Click here for more information.

TALLAHASSEE, Fla. -- Working with colleagues from NASA, a Florida State University researcher has published a paper that calls into question three decades of conventional wisdom regarding some of the physical processes that helped shape the Earth as we know it today.

Munir Humayun, an associate professor in FSU’s Department of Geological Sciences and a researcher at the National High Magnetic Field Laboratory, co-authored a paper, “Partitioning of Palladium at High Pressures and Temperatures During Core Formation,” that was recently published in the peer-reviewed science journal Nature Geoscience. The paper provides a direct challenge to the popular “late veneer hypothesis,” a theory which suggests that all of our water, as well as several so-called “iron-loving” elements, were added to the Earth late in its formation by impacts with icy comets, meteorites and other passing objects.

“For 30 years, the late-veneer hypothesis has been the dominant paradigm for understanding Earth’s early history, and our ultimate origins,” Humayun said. “Now, with our latest research, we’re suggesting that the late-veneer hypothesis may not be the only way of explaining the presence of certain elements in the Earth’s crust and mantle.”

To illustrate his point, Humayun points to what is known about the Earth’s composition.

“We know that the Earth has an iron-rich core that accounts for about one-third of its total mass,” he said. “Surrounding this core is a rocky mantle that accounts for most of the remaining two-thirds,” with the thin crust of the Earth’s surface making up the rest.