Mike Tice, assistant professor in the Department of Geology and Geophysics, just might be changing the history books, one rock at a time.
A study of rocks, known as chert, that are 3.4 billion years old has revealed that early earth's conditions and temperature was much cooler than what previous research has shown.
"We get the old rocks and measure the composition of oxygen and hydrogen, and it turns out that they will have the same compositions as the oceans 3.4 billion years ago," Tice said.
He found through the isotopes preserved within the rocks that temperatures in the early ocean, at least in some spots on Earth, was about 40 degrees Celsius, which can be described as warm bath water. Previous to these findings researchers believed conditions were much hotter, around 70 degrees Celsius, 3.4 billion years ago.
The significance of the findings in rock temperatures is that at 40 degrees Celsius that capacity for photosynthetic organisms is much greater than if the temperature had been 70 degrees Celsius, Tice said.
"At 70 degrees with bacteria, it is hard to get really large communities," Tice said, "where at 40 degrees you can, and that is the basis of all modern food chains. It is what nearly every organism ultimately derives from."
The measurement of the amount of oxygen and hydrogen has been preserved in the chert is done through isotopes Tice said. Tice either has to drill out a part of the rock or dissolve the rock to look for amounts of hydrogen.
Tice and his colleague Michael Hren, of the University of Maryland, collected rocks from South Africa, which is one of the few places geologists can study rocks that range from such a long time ago.
"One key question in science is what was the condition of early earth three to four billion years ago," Hren said.
Hren and Tice studied samples of rocks that were once submerged within the ocean using an approach that had not been done before. Instead of measuring only the oxygen isotopes preserved within the rocks, the scientists decided to also include measurements of hydrogen isotopes, which they believe will give them more of an accurate estimation in temperature.
"With our approach we were able to go beyond in looking at it in a different way, we can make some estimates on what the ancient ocean composition must have been like," Hren said.
Jian Gong, a geology graduate student, works with Tice in other projects and is one of Tice's students. Gong said he is happy to be working with Tice.
"Every student needs to do research so I am doing it with Dr. Tice," Gong said. "I think his paper on the temperature in rocks is very interesting. They took a lot of time and effort with this research."
