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Cosmo lab


Cosmogenic nuclides are used by the Aarhus Cosmogenic Nuclides Group to determine erosion rates and model landscape evolution. At Department of Geoscience minerals are separated from sediment and rock samples to produce 10Be and 26Al:

  • Treatment with “Aqua Regia” (removal of metals and carbonates).
  • Floatation using CO2 (removal of feldspar and mica).
  • Boiling with phosphoric acid (removal of feldspar).
  • HF/HNO3 leaching (removal of silicate minerals and meteoric 10Be).

During semi-clean conditions the following steps are prepared:

  • Dissolution of “clean” quartz in HF, evaporation and chloride conversion (removal of Si)
  • Anion exchange (removal of Fe and Ti) and cation exchange (separation of Be and Al, removal of residual Ti and alkalis using HCl)
  • Precipitation using NH4OH (elimination of residual alkalis, Mg and Ca)
  • Oxidation at 800oC (conversion of Be and Al compounds)
  • Target preparation for AMS (pressing samples of BeO and Al2O3)

AMS measurements are performed at the AMS lab, Department of Physics and Astronomy.