The work was supported by the Nuclear Regulatory Commission under grant NRC-HQ-84-14-G-0059 and Oak Ridge National Laboratory through agreement number ORNL-675.-shipman- Note to Editors: The study abstract follows.An associated optimal sampling technique would involve using single grain etching.
Radioactive elements, such as rubidium-87 (but not strontium-86 or strontium-87), decay over time.
By evaluating the concentrations of all of these isotopes in a rock sample, scientists can determine what its original make-up of strontium and rubidium were.
And atoms of strontium-86 can diffuse more readily than atoms of strontium-87 or rubidium, simply because atoms of strontium-86 are smaller.
“It’s a slow process, but not necessarily a negligible one when you’re talking about geological time scales,” says Robert Hayes, an associate professor of nuclear engineering at NC State and author of a paper describing the work.
This function is able to tell researchers how old a sample is. But there’s a wrinkle in the process that has been overlooked.