Research could help archaeologists, geologists go back 1 million years

October 20, 2009

If it were possible to reliably date materials as old as 1 million years, scientists could learn that much more about how the environment has changed over time – and that’s just one of the benefits that Physics professor Bill Pagonis believes could result from his work toward perfecting a technique that examines how materials emit light.

Geologists and archaeologists also stand to gain from a greatly improved luminescence dating process, which now enables scientists to date materials as old as 100,000 years, Pagonis said in a recent interview in which he discussed how he spent his most recent sabbatical.

“We’re trying to push the line to go back further in time,” he said. “My goal is to contribute to that science as much as possible.”

During the 2008 fall semester, Pagonis collaborated with colleagues at the National Luminescence Laboratory in Denmark, where they examined the optical and thermal luminescence properties of quartz, a subject that has applications in geological and archeological dating.

“Quartz is in everything in nature,” Pagonis explained. “When you heat quartz, light and electrons are emitted. Geologists and archaeologists use quartz extensively to date things.”

Pagonis added that luminescence dating is a long-used process – going back about 40 years – but work is still needed to increase its reliability for dating even older objects.

Pagonis and his Denmark colleagues published their findings in the Journal of Luminescence earlier this spring. In the article, they wrote about their development of a model to explain how light and electrons can be emitted at the same time from quartz samples.

In addition to his work in Denmark, Pagonis presented two papers at a luminescence meeting in Beijing, China. He said the papers were the result of collaboration with colleagues from Israel, the United States and the United Kingdom. He also secured a contract from Wiley Publishing to co-author a book on luminescence with two colleagues from Israel and the United States. They hope to publish the book next summer.

Before heading to Denmark and during this past summer, Pagonis worked with a group of Physics majors. Pagonis and the five students investigated the optical properties of several types of quartz and feldspars, which are geological materials that are commonly found in archaeological pottery and in many types of geological formations. They also studied aluminum oxide, which is used for measuring radiation doses for workers working with radioactive materials.

“The study of the properties of these materials is important because geologists and archaeologists are always trying to find better methods for determining the age of geological formations and of human artifacts,” Pagonis said.

Earlier this year, the work was published in two papers in the Journal of Luminescence and the Journal of Physics D: Applied Physics. Physics professor Apollo Mian co-authored.

Pagonis said that work during his sabbatical gives him more insight to provide additional research opportunities for students.

“My long-term goal is to support research and research funding for students,” he said. “I want to promote as much research as possible, which fits nicely within the goals of the College.”