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Revision of Lower and Middle Rhine loess/palaeosol-sequences – First results of high resolution multi proxy analyses from Düsseldorf-Grafenberg and Remagen-Schwalbenberg

Peter Fischer1, Florian Steininger1, Nicole Klasen1, Ulrich Hambach2, Jens Protze3, Renate Gerlach4, Frank Lehmkuhl3, Alexandra Hilgers1, Ulrich Radtke5
1 Geographisches Institut, Universität zu Köln
2 Lehrstuhl für Geomorphologie, Universität Bayreuth
3 Geographisches Institut, RWTH Aachen
4 Landschaftsverband Rheinland, Bonn
5 Rektorat, Universität Duisburg-Essen

V 2.15 in Löss und terrestrische Archive (Fortsetzung)

18.09.2012, 17:40-18:00, H8

 

In the last two years, detailed geo-scientific studies were carried out in the Lower and Middle Rhine area in order to revise and refine the existing loess stratigraphy. The applied multi proxy approach combines geomorphological-pedological methods, sedimentological and geochemical analyses as well as luminescence dating. Analyses were conducted on drill cores which have been sub-sampled in 5 cm and 2.5 cm intervals for laser particle size analyses, the determination of rock magnetic parameters and for element determination (XRF), respectively.

Selected samples were dated using the OSL signal of quartz (40-63 µm) and the post-IR IRSL signal of potassium-rich feldspar (63-100 µm).

The drill core from the section of Düsseldorf-Grafenberg comprises 18.75 m of loess and soil sediments as well as intercalated interstadial soils on top of the Upper terrace of the river Rhine. Based on the age model, which is strongly supported by field evidence and laboratory analyses the sequence contents sediments covering the time period  from OIS 6 to OIS 2, while the loess sediments and intercalated Gelic Gleysols of OIS 2 show the major thickness (approx. 11m).  In contrast, the section of Remagen-Schwalbenberg contents a minor amount of Upper Weichselian loess sediments including the Eltville Tephra, but a long sequence of Middle Weichselian loess and intercalated (partly reworked) calcaric cambisols. Following the quartz based age model, the lower part of the sequence containing the partly reworked calcaric cambisols accumulated in a relatively short time period during OIS 3.

Figure 1 is showing the Grain Size Index indicating unequal transport and accumulation processes within both sequences. It becomes obvious that different accumulation models not only considering the morphological position have to be developed to understand the composition of the sections under study.

Multi element contents and derived ratios as well as rock magnetic parameters facilitate a classification of the loess strata and provide correlations to weathering intensities.

All in all, the analyzed key sites deliver essential information on environmental change during the last glacial cycle in the study area. Different accumulation models as well as stratigraphical correlation to other important sections in Europe along a transect from northwest to southeast against the background of global climate change during the last glacial cycle will be presented and critically discussed.

 

References:

Antoine, P., Rousseau, D.D., Moine, O., Kunesch, S., Hatté, C., Lang,
A., Tissoux, H. & Zöller, L. (2009): Rapid and cyclic aeolian deposition
during the Last Glacial in European loess: a high-resolution
record from Nussloch, Germany. – Quaternary Science Reviews, 28
(25-26): 1–19.

Grain Size Indices (modified after Antoine et al. 2009) for the Loess/palaeosol sequences of Düsseldorf-Grafenberg (left) and Remagen-Schwalbenberg (right).
Grain Size Indices (modified after Antoine et al. 2009) for the Loess/palaeosol sequences of Düsseldorf-Grafenberg (left) and Remagen-Schwalbenberg (right).



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Letzte Änderung 31.07.2012