Constraining processes of landscape change with combined in situ cosmogenic 14C-10Be analysis

Reconstructing Quaternary landscape evolution today frequently builds upon cosmogenic-nuclide surface exposure dating. However, the study of complex surface exposure chronologies on the 10(2)-10(4) years' timescale remains challenging with the commonly used long-lived radionuclides (Be-10, Al-26, Cl-36). 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-lived in situ cosmogenic C-14 isotope with Be-10 dating provides a valuable approach to resolve and quantify complex exposure histories and burial episodes within Lateglacial and Holocene timescales. The first studies applying the in situ C-14-Be-10 pair have demonstrated the great benefit from in situ C-14 analysis for unravelling complex glacier chronologies in various glacial environments worldwide. Moreover, emerging research on in situ C-14 in sedimentary systems highlights the capacity of combined in situ C-14-Be-10 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 available in situ C-14 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 combined in situ C-14-Be-10 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. (C) 2017 Elsevier Ltd. All rights reserved.