Cosmogenic nuclide laboratory
Cosmogenic nuclides, such as beryllium-10, aluminium-26, and carbon-14 among others, are rare isotopes of elements produced through interactions of cosmic radiation with nuclei in Earth’s atmosphere and surface. Because we know the rates at which these isotopes are produced, the concentrations of cosmogenic nuclides in rock, soil, sediment, etc. can be used to determine how long that material has been exposed at Earth’s surface. This allows us to calculate exposure ages and erosion rates at Earth’s surface.
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. We currently process ~100 samples per year for a number of cosmogenic nuclides, such as beryllium-10, aluminium-26, and chlorine-36, from a wide variety of lithologies, but have the capacity for over 200 samples per year.
The applications of cosmogenic nuclide methods span the Earth Sciences. Absolute sating of glacial moraines and river terraces, for example provide vital constraints on paleo-climate impacts on the landscape. Cosmogenic nuclides can be used to date fault scarps and the occurrence of large landslides, helping us understand tectonics and earthquake hazards and recurrence intervals. Soil production rates and erosion rates can likewise be determined by measuring nuclide concentrations in soils or river sediment, respectively, providing constraints of soil sustainability and flood hazard.
- Richard Jones, PhD – Behaviour of outlet glaciers in the Transantarctic Mountains during the Late Cenozoic.
- Julia Collins, MSc – In-situ cosmogenic beryllium-10 in pyroxenes for moraine surface exposure dating.
- Sam Webber, MSc – The active Mai’iu low angle normal fault: Spatial and temporal slip distributions, and the chronology of rider block abandonment.
- Cam Watson, MSc - Constraining an absolute age for the K-Surface and the determination of the vertical tectonic history of western Wellington.
Abby Burdis, MSc 2014 - Denudation rates derived from spatially-averaged cosmogenic nuclide analysis in Nelson/Tasman catchments, South Island, New Zealand