in situ cosmogenic 14C- 10Be analysis]]>

摘要

AbstractReconstructing Quaternary landscape evolution today frequently builds upon cosmogenic-nuclide surface exposure dating. However, the study of complex surface exposure chronologies on the 102–104years’ timescale remains challenging with the commonly used long-lived radionuclides (10Be,26Al,36Cl). In glacial settings, key points are the inheritance of nuclides accumulated in a rock surface during a previous exposure episode and (partial) shielding of a rock surface after the main deglaciation event, e.g. during phases of glacier readvance. Combining the short-livedin situcosmogenic14C isotope with10Be dating provides a valuable approach to resolve and quantify complex exposure histories and burial episodes within Lateglacial and Holocene timescales. The first studies applying thein situ14C-10Be pair have demonstrated the great benefit fromin situ14C analysis for unravelling complex glacier chronologies in various glacial environments worldwide. Moreover, emerging research onin situ14C in sedimentary systems highlights the capacity of combinedin situ14C-10Be analysis to quantify sediment transfer times in fluvial catchments or to constrain changes in surface erosion rates. Nevertheless, further methodological advances are needed to obtain truly routine and widely availablein situ14C analysis. Future development in analytical techniques has to focus on improving the analytical reproducibility, reducing the background level and determining more accurate muonic production rates. These improvements should allow extending the field of applications for combinedin situ14C-10Be analysis in Earth surface sciences and open up a number of promising applications for dating young sedimentary deposits and the quantification of recent changes in surface erosion dynamics.Highlights?Concept and applications of combinedin situ14C-10Be analysis is shown.?Analytical procedures forin situ14C extraction from quartz are demanding.?Thein situ14C-10Be pair allows dating complex surface exposure histories.?In situ14C-10Be da