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- The Cosmogenic Nuclide Lab at the University of Washington provides an overview
of cosmogenic isotope research and as a repository for data generated by the
group, descriptions of our lab procedures, technical information and
calculation methods.
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. Where surfaces are
gradually evolving, cosmogenic isotope measurements allow us to calculate
erosion or soil accumulation rates.
[Summary provided by the University of Washington.]
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