In situ produced cosmogenic krypton in zircon and its potential for Earth surface applications

Abstract

Abstract. Analysis of cosmogenic nuclides produced in surface rocks and sediments is a valuable tool for assessing rates of processes and the timing of events that shaped the Earth surface. The various nuclides that are used have specific advantages and limitations that depend on the time-range over which they are useful, the type of material they are produced in, and not least the feasibility of the analytical effort. Anticipating novel applications in Earth surface sciences, we develop in-situ produced terrestrial cosmogenic krypton (Krit) as a new tool; the motivation being the availability of six stable and one radioactive isotope (81Kr, half-life 229 kyr) and of an extremely weathering-resistant target mineral (zircon). We provide proof of principle that terrestrial Krit can be quantified and used to unravel Earth surface processes.

Unraveling the climate control on debris-free glacier evolution in the Everest region (Nepal, central Himalaya) during the Holocene

“…During the Late Holocene larger glacier advances than during the Mid-Holocene would have eroded earlier pre-exposed bedrock surfaces but not totally removed 10 Be accumulated during these previous Mid-Holocene periods free of ice. One may also hypothesize that 10 Be might have accumulated when ice thickness was reduced to a few meters due to energetic muon particles (Dunai, 2010). In such a hypothesis the retreat of the glacier during the Mid-Holocene or periods during the Late Holocene could have just been slightly smaller than the latest Late Holocene glacier advances which caused larger extents evidenced by the dated moraines reported in this study.…”