A chronological and palaeoenvironmental re‐evaluation of two loess‐palaeosol records in the northern Harz foreland, Germany, based on innovative modelling tools

Détails

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Version: Final published version
Licence: CC BY 4.0
ID Serval
serval:BIB_E4E18C1E9853
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
A chronological and palaeoenvironmental re‐evaluation of two loess‐palaeosol records in the northern Harz foreland, Germany, based on innovative modelling tools
Périodique
Boreas
Auteur⸱e⸱s
Schmidt Christoph, Zeeden Christian, Krauß Lydia, Lehmkuhl Frank, Zöller Ludwig
ISSN
0300-9483
1502-3885
Statut éditorial
Publié
Date de publication
04/02/2021
Peer-reviewed
Oui
Volume
50
Pages
746-763
Langue
anglais
Résumé
The continuing development of analytical methods for investigating sedimentary records calls for iterative re-examination of existing data sets obtained on loess-palaeosol sequences (LPS) as archives of palaeoenvironmental change. Here, we re-investigate two LPS (Hecklingen, Zilly) in the northern Harz foreland, Germany, being of interest due to their proximity to the Scandinavian Ice Sheet (SIS) and the position between oceanic climatic influence further west and continental influence towards the east. First, we established new quartz OSL and polymineral IRSL chronologies. Both methods show concordant ages in the upper part of the Hecklingen profile (~20–40 ka), but in the lower part IRSL underestimates OSL ages by up to ~15 ka for the period 40–60 ka. Interpretations hence refer to the OSL data set. Second, we applied Bayesian age-depth modelling to data sets from Hecklingen to resolve inversions in the original ages, also reducing averaged 1σ uncertainty by ~19% (OSL) and ~12% (IRSL). Modelled chronologies point out phases of increased (MIS 2, early MIS 3) and reduced (middle and late MIS 3) sedimentation, but interpretation of numerical rates is problematic because of intense erosion and slope wash particularly during MIS 3. Finally, previously obtained grain-size data were re-investigated by end member modelling analyses. Three fundamental grain-size distributions (loadings) explain the measured data sets and offer information on intensity and – combined with modelled OSL ages – timing of geomorphic processes. We interpret the loadings to represent (i) primary loess accumulation, (ii) postdepositional pedogenesis and/or input of aeolian fine fractions, and (iii) input of coarse aeolian material and/or slope wash. The applied modelling tools facilitate detailed understanding of site-formation through time, allowing us to correlate a strong peak in mean grain size at ~26–24 ka to the maximum extent of the SIS and increased influence of easterly winds.
Mots-clé
Archaeology, Geology, Ecology, Evolution, Behavior and Systematics
Web of science
Open Access
Oui
Financement(s)
Autre / ZO51-39-1
Autre / ID 57444011 - SFB 806
Création de la notice
01/03/2021 11:41
Dernière modification de la notice
24/12/2022 7:44
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