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Differentiation of loess sequences and their geomorphology - examples from Central and Eastern Europe

Frank Lehmkuhl1, Jens Protze1, Holger Kels1
1 Lehrstuhl für Physische Geographie und Geoökologie, RWTH Aachen University

V 2.11 in Löss und terrestrische Archive (Fortsetzung)

18.09.2012, 16:20-16:40, H8

Investigations from the northern margin of loess accumulation and the transition towards the mountainous regions in central Europe show a differentiation within the loess, towards the northern margin, and by the elevation.

In the Lower Rhine Embayment it is possible to differentiate the loess sections, especially in paleochannels with re-worked loess sequences up to more than 20 m. In such situations pre-Eemianloesses,paleosol complexes(OIS 5 and 3) and two main sequences of Weichselian loess (alluvial loess (OIS 4) and parts of  Upper Weichselian loess can be preserved (see Fig. 1).
Towards the top, the widely distributed late Upper Weichselian loess (OIS 2), beginning with the so-called Ebendiscordances and the cryoturbation horizon of the Kesselt layer, is covering former loess units(Fischer et al. 2012, Kels 2007, Schirmer 2010, 2003).

At the northern margin of the Harz Mountains the thin layers of 2 to 5 m Weichselian loess can also be divided in the basal alluvial loess followed by a discordance and LGM to late Glacial covering loess (Fig. 1, Reinecke 2006). In addition, in this region loess sedimentation of the Younger Dryascan be differentiated. Towards the northern margin of the European loess belt in both regions a strata interlocking from more silty to sandyloess and sand sheets occur.

In the mountains dust born silt is incorporated in the upper and intermediate periglacial cover-beds. The upper cover-bed dates to the Younger Dryas period. The mountains front is less steep in the Eifel Mountains, and therefore in this region a transition zone with isolated patches of loess occurs (Fig. 1).

In Eastern Europe and also in Austria we also postulate a transition of loess sedimentation towards higher mountain areas. Whereas in Lower Austria no loess accumulation occur in the higher areas of Bohemian bedrock, a thin layer of loess sediments is developed in higher areas of the Banat Mountains of Romania. In the lowlands of both regions up to more than 20 m of Pleistocene loess-paleosol sequences can be distinguished. In Austria the patches of loess are of different Pleistocene time influenced by undulation relief with several small valleys and different position on the slopes (e.g. Thiel et al. 2011). In contrast,in the lowland of Serbia, Hungary and Romania more or less complete loess paleosol sequences occur (Kels et al. 2012, Marković et al. 2012).

In addition recent methodological improvements, especially of grain size and multielement analysis, offer a new assessment of loess-palaeosol-sequences.

References

Fischer, P., Hilgers, A., Protze, J., Kels, H., Lehmkuhl, F.& Gerlach, R. (2012): Formation and Geochronology of Last Interglacial to Lower Weichselian loess/palaeosol sequences – case studies from the Lower Rhine Embayment, Germany. –E & G Quaternary Science, 61: 48-63.

 Kels, H. (2007): Bau und Bilanzierung der Lössdecke am westlichen Niederrhein. - Inaug.-Diss. Heinrich-Heine-Universität Düsseldorf: 206 S. Düsseldorf.

 Kels, H., Protze, J., Sitlivy, V., Hilgers, A., Zander, A., Anghelinu, M. & Lehmkuhl, F.: Genesis of loess-like sediments and soils at the foothills of the Banat Mountains, Romania – Examples from the Paleolithic sites Româneşti and Coşava. – Quaternary International, submitted.

 Marković, S., B., Hambach, U., Stevens, T., Basarin, B., O’Hara-Dhand, K., Gavrilov, M. M., Gavrilov, M. B., Smalley, I. &Teofanov, N. (2012): Relating the Astronomical Timescale to the Loess–Paleosol Sequences in Vojvodina, Northern Serbia. – In: Berger, A. et al. [eds.]: Climate Change, Part 2: 65-78.

Reinecke, V. (2005): Untersuchungen zur mittel- und jungpleistozänen Reliefentwicklung und Morphodynamik im nördlichen Harzvorland. - Aachener Geographische Arbeiten 43 (2006), 196 p.

 Schirmer, W. (2003): Die Eben-Zone im Oberwürmlöss zwischen Maas und Rhein. – In: Schirmer, W. [Hrsg.]: Landschaftsgeschichte im Europäischen Rheinland. GeoArchaeoRhein, 4: 351-416; Münster.

 Schirmer, W. (2010): Interglacial complex and solcomplex. – Central European Journal of Geosciences, 2 (1): 32-40.

 Thiel, C., Buylaert, J.-P., Murray, A. S., Terhorst, B., Tsukamoto, S., Frechen, M. &Sprafke, T. (2011): Investigating the chronostratigraphy of prominent palaeosols in Lower Austria using post-IR IRSL dating. - E & G Quaternary Science Journal, 60(1): 137-152.

Fig. 1: Model of horizontal and vertical distribution of loess sediments and cover-beds in the northern margin of the Eifel and Harz Mountains.
Fig. 1: Model of horizontal and vertical distribution of loess sediments and cover-beds in the northern margin of the Eifel and Harz Mountains.



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Letzte Änderung 07.08.2012