School of GeoSciences 1 INTRODUCTION 3 CAPABILITIES 5 APPLICATIONS Terrestrial cosmogenic nuclides form in Cosmogenic nuclide concentrations are commonly used to determine ‘exposure rock minerals exposed in the upper ~2 m ages’ and ‘erosion rates’. Some common examples include: of Earth’s surface through interaction with cosmic radiation (Fig. 1). The Exposure dating concentration of cosmogenic nuclides in • Glacier erosion/deposition surfaces: striated bedrock, erratics, moraines near surface rocks will increase through • Fluvial and glaciofluvial terraces time until their production is matched by • Buried sediments: caves, glacial till their losses through physical erosion and • Rockfalls radioactive decay. Thus, the Rock crushing and sieving • Fault scarps concentration of cosmogenic nuclides in ‐Dedicated lab space •Lavaflows A rock or sediment is a balance between ‐Disk mill • Flood deposits its exposure time and erosion rate. This • Alluvial fans 10Be ~98% production ‐Sieves knowledge can be applied in a range of 16O(n,4p3n)10Be 28Si(n,6p3n)210Be ‐Frantz magnetic separator settingstoquantifydatesandratesof ‐Sample splitter Earth surface processes. 26Al ~98% production 28Si(n,p2n)26Al Extraction of quartz from rock/sediment ‐Dedicated lab space ‘Target’ nucleus ‐Shaker tables 16O ‐Ultrasonic baths B Fig. 1. Cosmogenic nuclide production occurs in near ‐Frantz magnetic separator AB surface rocks, mainly through spallation reactions (left diagram): a fast incoming particle hits the nucleus of an ‐HF‐rated fume cupboard with scrubber atom. Nucleons (protons and neutrons) are sputtered ‐Scales C Spallation reaction 10 Be off leaving a lighter residual nucleus behind. ‐Ovens Preparation of 10Be, 26Al and 36Cl targets Figure 3. A) Cosmogenic 10Be dating of glacial erratics to contrain the timing of thinning of the Antarctic Ice Sheet. B) 26 10 21 ‐2xDedicated clean labs Figure 2. A) Cosmogenic nuclide depth profiles can Use of multiple cosmogenic nuclides ( Al, Be and Ne) ‐3xHF/Perchloric acid‐rated fume add valuable information on the age, erosion rate cangiveinsightontheexposurehistory;itispossibleto 2 FACILITY DESCRIPTION and inheritance. Here a 10Be depth profile is use to determine if a rock has been continuously exposed, or if it cupboards and scrubbers constrain the age of a glacial outwash terrace. B) has been buried for a significant period of time. C) We have ‐Laminar flow fume cupboard Modelling can then be used to optimise the best fit used this information to constrain the history of the West to the data (Hein et al., 2009). Antarctic Ice Sheet (Hein et al., 2016a, 2016b). This facility is designed to make ‐Ultrapure water system possible the measurement of ‐Scales Rates of landscape change cosmogenic nuclides in rock and ‐Press • Rock surface erosion rates sediment. Here, we chemically ‐Ovens • Land surface degradation rates extract cosmogenic isotopes from •Basin‐wide erosion rates rock and sediment and prepare • River incision rates targets ready for measurement by • Modern erosion (meteoric 10Be) Accelerator Mass Spectrometry 4THE PROCESS •Fault‐slip rates (AMS). We are able to support preparation work for all of the major • isolate target mineral cosmogenic isotopes including • remove meteoric variety cosmogenic 10Be, 26Al, 36Cl, 21Ne, 3He and 14C. The AMS or MS analyses Figure 3. Cosmogenic nuclides can be used to constrain areconductedattheScottish basin‐wide erosion rates. In this case, providing data that Universities Environment Research can be used to constrain land surface erosion models (Hurst Sample Crush Mill and sieve Acid etch et al., 2013). Centre or other collaborative Crush institutions. 10Be concentration! 26Al concentration! Chemical isolation and 36Cl concentration! purification of 10Be, 26Al 6 FURTHER INFORMATION What can be analysed? Most nuclides are measured from within quartz minerals. Therefore, any AMS target We have a full‐time laboratory technician, post docs and PhD students associated quartz‐rich rock or sediment can be with the lab. Charges are set for analyses to recover costs through a model analysed. However, chlorine can be recognised by UK Research Councils. We offer a reduced rate for PhD research measured in nearly any rock, and is projects. If you are considering a project that would involve cosmogenic nuclide particularly useful for carbonate rocks analysis, please speak to us! such as limestone. Contact: Dr. Andrew Hein [email protected].