The Columns

Summer Research Means Yellow Jackets, X-ray Diffractometer and Dirt

— by on July 23rd, 2009

Stepping on a nest of yellow jackets is just part of Meredith Townsend’s experience during her summer research project at Washington and Lee University.

She also spent a day poring over a manual to work out how to operate the X-ray diffractometer because no one had used it for such a long time. Then there was the week-long impatient wait for a delivery of hydrogen peroxide to treat her soil samples.

But Townsend said those frustrations are countered by the experience of conducting research in the field.

A rising junior geology major, Townsend is a R. E Lee Research Scholar at W&L and has been working on a research project with David Harbor, professor of geology.

Washington and Lee’s R.E. Lee Summer Scholars, part of the University’s undergraduate research program, is in its fifth decade of operation. It was founded in 1960 by an 1899 graduate. Students must be nominated for the opportunities, which involve either assisting a professor in research or carrying out a student-planned project under the supervision of a professor.

In the case of Townsend and Harbor, the project is one small part of a broad new multinational effort funded by a five-year multimillion dollar grant from the National Science Foundation, and is based at Pennsylvania State University.

W&L is one of six satellite sites on the project. The center is the Shale Hills site in central Pennsylvania. The satellite sites are located along a climatic gradient in the mid-Atlantic region and are being used to test the models developed at Shale Hills, and to provide regional data on weathering rates as a function of climate changes.

In addition to W&L, the other satellite sites are operated by Colgate University, the University of Tennessee, Baylor University, Alabama A & M University, the University of Puerto Rico-Mayaguez, and Juniata College.

“If you go back to the Dust Bowl,” said Harbor, “we mined the soil to such a degree that it couldn’t hold organic matter. When that happens, the soil can’t hold water. So we need to understand the dynamics of the production of soil, how it is produced, how long it stays on the surface, what happens as it moves across the land surface. It’s critical research for an important part of the ecosystem.”

“Although we know a lot about soil, nobody has put enough numbers to it yet so that we can say whether we are using the soil in a sustainable or unsustainable way.”

In order to find that out, the research is looking at how the same kind of rock-shale bedrock-turns into soil in roughly the same place at the top of a hill, but in different climates. Those climates range from upstate New York to the southern Appalachians, Puerto Rico, Wales and South America.

“It’s based on what is called a critical zone between the bedrock and the top of the trees,” said Harbor, “and includes all the activities of biological actors within that zone such as trees, plants and the weathering that turns bedrock into soil. It’s complex because there are a lot of interactions going on within the zone, and we don’t actually know much about it.
“It’s so complex that we need an ecologist, hydrologist, geologist and other scientists to work on the whole thing.”

“We’re collecting samples of the parent rock and soil samples from the shale within a very narrow zone of just ten meters thick. Then we’re doing geochemistry, using an electron microscope and X-ray defractometer to look at the physical and chemical differences up and down the soil,” he said.

Townsend and Harbor are working at a number of different sites in areas around Lexington, including one just south of Clifton Forge and one at the top of White Rock Mountain, which is east of Brattons Run in Western Rockbridge County.
Harbor plans to continue the research after the summer by erecting a monitoring station to measure soil moisture, temperature and precipitation that the geology department will monitor for three or four years.

Townsend plans to pursue a career in geosciences after graduate school, maybe a combination of research and teaching at a university.

In the meantime, there’s the small matter of retrieving the equipment they left at the yellow jackets’ nest…