can be used to determine how long that material has been exposed at Earth’s surface.
Where surfaces are gradually evolving, cosmogenic isotope measurements allow us to calculate erosion or soil accumulation rates.
This site explains some of the background to our work and provides an overview of cosmogenic isotope research at the University of Washington.
The Cosmogenic Nuclide Laboratory at SGEES was purpose built in 2014 for the preparation of cosmogenic nuclide samples from all branches of the Earth sciences.
The facilities include 2 HF rated extraction hoods and one laminar flow hood, Parr pressure dissolution oven, as well as analytical balances and centrifuge.
High-energy cosmic rays shower the Earth's surface, penetrating meters into rock and producing long-lived radionuclides such as Cl-36, Al-26 and Be-10.
Production rates are almost unimaginably small - a few atoms per gram of rock per year - yet we can detect and count these "cosmogenic isotopes" using accelerator mass spectrometry, down to levels of a few thousand atoms per gram (parts per billion of parts per billion! The build-up of cosmogenic isotopes through time provides us with a way to measure exposure ages for rock surfaces such as fault scarps, lava flows and glacial pavements.