Frank Spear honored for his work to understand Earth’s history and formation

Troy, N.Y. — Frank Spear, department chair and professor of earth and environmental sciences at Rensselaer Polytechnic Institute, has been elected as a fellow of the American Geophysical Union (AGU).

“Rocks tell a story,” Spear said, surrounded by hundreds of glass-encased rock samples. It has been Spear’s lifelong mission to ensure that each rock’s story is told, and his election as a fellow of the world’s largest geophysical organization proves that his storytelling has caught the attention of colleagues around the world.

This prestigious honor is limited to no more than 0.1 percent of the AGU’s total membership each year, which includes more than 45,000 scientists from 140 countries.

“It is really an honor,” Spear said. “I am doing what I love to do every day; not many people can say that about their job.” 

Spear’s work to uncover the history of Earth’s formation has taken him around the world. His research focuses on developing techniques to analyze the mineral and chemical reactions that form the crystalline rocks that make up Earth’s crust, a branch of geology known as metamorphic petrology. 

Spear’s goal is to develop methods researchers can use to create a tectonic history of a terrain. His research looks at the record of various elements in metamorphic rocks to reconstruct a timeline of the rock’s formation. Many of these elements are combined and altered during mountain-building episodes when tectonic plates collide.

During such an episode, metamorphic rocks experience great changes in pressure and temperature. In response to these changes in pressure and temperature, the rocks react, forming new minerals. As they grow, these new minerals record in their chemistry the changes in pressure and temperature that they experienced.  The minerals can then act as chemical tape recorders or geothermometers that, when played back through rigorous thermodynamic analysis, can reveal the pressure and temperature the rock reached during its formation.

Much of Spear’s current research is focused on the distribution of trace elements such as scandium, chromium, titanium, phosphorous, and particularly yttrium in garnet. And he is working to develop new methods for determining the pressure-temperature-time history of a terrain. 

Thanks in large part to Spear’s research, geologists now understand that these trace elements preserve the history of a rock to a much larger degree than more major elements like iron, magnesium, manganese, and calcium. This work opens the field to discovery of segments of Earth’s history that were previously unknown. 

He is currently working to extend this approach to include quartz, one of the world’s most common metamorphic minerals. The research will strive to determine the temperature of quartz crystallization by using traces of titanium in the quartz as a geothermometer. “When we’re lucky, these new analyses begin to tell a story that we didn’t even know was there to read,” Spear said. “It’s like finding hidden pages in one of your favorite novels with entirely new details of the plot.”

Spear has applied his techniques to areas in the Alps, Chile, British Columbia, the Mojave Desert, the Adirondacks of New York, the Limpopo Belt of South Africa, and the Caledonides of Norway. He will be expanding his research with a visit this summer to Greece and the Cyclades Blueschist Belt on the islands of Syros and Sifnos, where he will work to determine the tectonic history of burial and uplift on this crustal belt, providing new insight into the processes that shaped Earth’s surface.

“When you work with Earth, your work is never done,” Spear said.

Spear will receive the award at a formal award ceremony during the 2007 Joint Assembly of the AGU in Acapulco, Mexico in May 2007.

Spear began his career at Rensselaer in July 1985. He was named chair of the Department of Earth and Environmental Sciences in 1999. Before coming to Rensselaer, Spear taught as an associate professor of geology at the Massachusetts Institute of Technology. He earned a B.A. from Amherst College and a Ph. D. from the University of California, Los Angeles, both in geology.

The AGU is a nonprofit scientific organization that was established in 1919 by the National Research Council (NRC).  The group works to promote study of the atmosphere, earth, space, and water. It fosters cooperation among geophysicists around the world, participates and facilitates research programs, and works to advance the Earth sciences. 

Contact: Gabrielle DeMarco
Phone: (518) 276-6542
E-mail: demarg@rpi.edu