orangeleader.com (Orange, Texas)

April 2, 2013

LU scientists explore novel fossil dating

Special to The Leader
The Orange Leader

BEAUMONT — Three Lamar University scientists and three undergraduate research assistants traveled to Washington D.C. during the week of spring break to participate in testing a novel new approach to dating fossils.

Radiocarbon dating is well established as the go-to method for determining the age of organic materials, however this method only yields results back to about 50,000 years, said Jim Westgate, University Professor of Earth and Space Sciences, and therefore isn’t used to date older fossils.

Joining Westgate were George Irwin, associate professor of physics, and Jim Jordan, chairman of the Department of Earth and Space Sciences. Participating in the research are Christine Gartner, a senior geology major from Beaumont, and physics majors Jason Dark, a junior from Beaumont and Joshua Kamienski, a senior from Houston.

Typically, fossils older than 50,000 years are dated based on igneous or metamorphic rocks that are associated with the fossils, or by rare associations of fossils with radiometrically datable materials, Westgate said.

“We are trying to see if we can age the teeth by their radioactivity,” Westgate said. Lamar’s physics team spent several weeks doing preliminary analysis of fossil megalodon and mammoth teeth ranging in age from 13,000 to 70 million years old.

“Preliminary results indicate we might be able to extend the direct age dating process to 30- or 40-million years,” Westgate said.

With these promising results “we took a Geiger counter into the Smithsonian museum collections to find ‘hot’ megalodon teeth to borrow for analysis in the LU Physics Radiation Lab,” Westgate said.

The team was granted access to fossil radioactive C. megalodon shark teeth in the collection of the Smithsonian Institution's National Museum of Natural History. The museum will loan Lamar about 20 teeth ranging in age from 4 million to 150 million years, Westgate said.