Beryllium 10 (10Be) concentrations from till in the western Swiss lowlands

DOI

During the Pleistocene, glaciers advanced repeatedly from the Alps onto the Swiss Plateau. Numeric age control for the last glaciation is good and thus the area is well suited to test a method which has so far not been applied to till in Switzerland. In this study, we apply in situ produced cosmogenic 10Be depth profile dating to several till deposits. Three sites lie inside the assumed Last Glacial Maximum (LGM) extent of the Rhône and Aare glaciers (Bern, Deisswil, Steinhof) and two lie outside (Niederbuchsiten, St. Urban). All sites are strongly affected by denudation, and all sites have reached steady state, i.e., the 10Be production is in equilibrium with radioactive decay and denudational losses. Deposition ages can therefore not be well constrained. Assuming constant denudation rates of 5 cm/kyr, total denudation on the order of 100 cm for sites within the extent of the LGM and up to tens of meters for older moraines are calculated. Denudation events, for example related to periglacial conditions during the LGM, mitigate the need to invoke such massive denudation and could help to explain high 10Be concentrations at great depths, which we here dub "pseudo-inheritance". This term should be used to distinguish conceptionally from "true inheritance", i.e., high concentrations derived from the catchment.

Supplement to: Wüthrich, Lorenz; Brändli, Claudio; Braucher, Régis; Veit, Heinz; Haghipour, Negar; Terrizzano, Carla; Christl, Marcus; Gnägi, Christian; Zech, Roland (2017): 10Be depth profiles in glacial sediments on the Swiss Plateau: deposition age, denudation and (pseudo-) inheritance. E&G - Eiszeitalter und Gegenwart - Quaternary Science Journal, 66(2), 57-68

Identifier
DOI https://doi.org/10.1594/PANGAEA.884060
Related Identifier https://doi.org/10.5194/egqsj-66-57-2017
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.884060
Provenance
Creator Wüthrich, Lorenz ORCID logo; Brändli, Claudio; Braucher, Régis ORCID logo; Veit, Heinz; Haghipour, Negar; Terrizzano, Carla; Christl, Marcus ORCID logo; Gnägi, Christian; Zech, Roland
Publisher PANGAEA
Publication Year 2017
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 181 data points
Discipline Earth System Research
Spatial Coverage (7.453W, 46.922S, 7.855E, 47.286N); Switzerland