The Oldest Material On Earth Is At RPI

by Gabrielle DeMarco on October 6, 2010

No jokes about an aging professor allowed here. The oldest material on Earth looks pretty much like something you dug out of your backyard. But this material, direct from the Jack Hills of Australia, is an exceptionally important cornerstone (pun intended) in the search for the origins of life on Earth.

The rock, which is used in both sophisticated geochemical research and as an eons-old paperweight by Professor Bruce Watson, has pepper flecks of zircon crystal that date back to approximately 4.4 billion years ago. That is 95-96 percent of the age of Earth!

Each of the tiny zircon crystals contains chemical information about the environment that was present at the time of their formation, known as crystallization. Babies are born. Rocks are crystallized.

Watson’s work with zircons is groundbreaking in geology. He developed a way to measure the titanium content of the zircon that reveals their temperature at the time of crystallization. His work with Jack Hill’s rocks like this one show that the zircon was formed at temperatures consistent with those of rocks formed in the presence of liquid water. His discovery provides important evidence for the existence of liquid water on Earth very soon after its formation.

Remember we are taking about water on an early planet that many scientists thought looked like this:

The finding is particularly important to understanding how and when life formed on Earth. Thanks in large part to Watson, early Earth is now believed to have been a much more viable place for the development of life.

Watson, a member of the New York Center for Astrobiology, is now looking to learn even more of the story that the Jack Hills rocks have to say. He is looking at how the materials surrounding the zircon, most notably quartz, can be also be analyzed for additional information.

A lot more on origins research at Rensselaer is coming. I am working on a feature for the winter edition of Rensselaer magazine.