Discovery in the Dark

A new laboratory at Utah State University provides innovative opportunities in earth science research for undergraduates and seasoned researchers alike. 

The USU Luminescence Laboratory, located on the university’s Innovation Campus, features cutting-edge capabilities in optically stimulated luminescence or ‘OSL’ geochronology. The technology enables geologists, archaeologists and other scientists to accurately determine the age of sediment samples.

 

“I’m always looking for ways to involve students in research,” says Joel Pederson, associate professor of geology and lab director. “The new lab offers great opportunities for undergraduates and graduate students to learn about luminescence dating and conduct projects on their own.”

 

Recent technological advances in luminescence dating make it one of the most powerful, accurate and cost-effective methods for solving geological questions, he says.

 

OSL offers a number of advantages over conventional methods such as radiocarbon and cosmogenic dating of young geologic samples. The latter methods are difficult and costly, which means neither is conducive to student research. In addition, luminescence dating allows use of tiny samples that enable researchers to date fragile archaeological sites without causing damage.

 

Only a handful of similar labs are located in the United States. Prior to the USU lab’s opening in 2007, Pederson was sending research samples to out-of-state facilities.

 

“I concluded, ‘Why use our precious research funding to send samples and students somewhere else when we could be doing the work here?’” Pederson says.

 

The lab’s core instrument, funded by a grant from the Val A. Browning Foundation, is a luminescence reader developed by Denmark’s renowned Risø National Laboratory. About the size of a personal computer, the reader uses controlled doses of radiation and light to incite and measure the responding light, or luminescence glow, of sand grains and thus determine their age.

 

The new tool is already attracting research dollars and opportunities. While Pederson envisions a regional focus for the lab, it already has clients in Asia and Alaska.

 

In February 2008, a USU geology research team, including Pederson, was awarded a $2.3 million contract from the U.S. Bureau of Reclamation to conduct a five-year study of archaeological sites in Grand Canyon. USU’s luminescence lab gave the university a competitive advantage in winning the contract, Pederson says.

 

“Projects such as this one and the time and effort we devote to measurement of samples from other universities will help fund the ongoing operations of the lab,” he says.

 

What was the lab’s first assignment? “We determined the age of Utah State University’s campus,” Pederson says.

 

No, not the date the university was established – that was 1888 – but the actual age of the ground upon which Aggies walk.

 

A September 2005 landslide just south of the USU campus exposed an inner section of the ancient Lake Bonneville benchmark. While citizens and local authorities fretted about the mishap’s implications for life, limb and property, Pederson and colleagues scrambled to collect precious samples.

 

“One of the primary challenges in earth science has always been determining the dimension of time – how old a canyon is, how long it takes to build a mountain range, how often earthquakes happen,” Pederson says. “I think it’s fitting that the very first age determination performed in our new lab was on the geologic material that forms USU’s foundation.”

 

So what did OSL dating performed at Utah State reveal about the age of the university’s campus?

 

“The samples are 19,300 years old, give or take 1,200 years,” Pederson says.