EGQSJE&G Quaternary Science JournalEGQSJE&G Quaternary Sci. J.2199-9090Copernicus PublicationsGöttingen, Germany10.5194/egqsj-66-101-2017Weichselian phases and ice dynamics of the Scandinavian Ice Sheet in
northeast Germany: a reassessment based on geochronological and
geomorphological investigations in BrandenburgHardtJacobjacob.hardt@fu-berlin.deFachbereich Geowissenschaften, Physische Geographie, Freie Universität Berlin, Berlin, GermanyJacob Hardt (jacob.hardt@fu-berlin.de)21December2017662101102This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/This article is available from https://egqsj.copernicus.org/articles/66/101/2017/egqsj-66-101-2017.htmlThe full text article is available as a PDF file from https://egqsj.copernicus.org/articles/66/101/2017/egqsj-66-101-2017.pdfcitationstatementHardt, J.: Weichselian phases and ice dynamics of the
Scandinavian Ice Sheet in northeast Germany: a reassessment based on
geochronological and geomorphological investigations in Brandenburg, E&G
Quaternary Sci. J., 66, 101–102, https://doi.org/10.5194/egqsj-66-101-2017, 2017.
Supervisors: Margot Böse, Markus
Fuchs, Christopher Lüthgens
This thesis presents new geochronological and geomorphological
data concerning Weichselian ice dynamics of the Scandinavian Ice Sheet for
the northeast German lowland area. The largest Weichselian ice extent in
Brandenburg (Brandenburg phase) occurred in the late marine isotope stage 3. The
global Last Glacial Maximum is represented by the Pomeranian ice marginal
position in Brandenburg (∼ 20 ka). Therefore, a 2-fold Last Glacial Maximum in Brandenburg, as previously proposed by Lüthgens and
Böse (2011), is confirmed.
Overview map showing compiled ages from the thesis (green) and other
authors (red/grey). OSL is optically stimulated luminescence dating. SED is
cosmogenic nuclide surface exposure dating. Figure modified from Hardt et
al. (2016) and references therein. See the respective paper and the thesis
for a detailed list of the cited ages.
For the first time, we determined optically stimulated luminescence (OSL)
ages of glaciofluvial deposits associated with the Weichselian Frankfurt
phase at a site in Ladeburg (central Brandenburg; Fig. 1). Furthermore, we
report new OSL ages of glaciofluvial deposits from the lignite mine
Jänschwalde (southern Brandenburg), a key site regarding the Weichselian
maximum extent during the Brandenburg phase. In combination with cosmogenic
nuclide surface exposure ages of glacigenic boulders, which were collected
from literature and recalibrated with an updated 10Be production rate,
a consistent process-based model of the Weichselian ice dynamics in
Brandenburg was developed (Fig. 1).
The ice advance of the Brandenburg phase was dated to 34.1 ± 4.6 ka.
For the formation of the Brandenburg ice marginal position, a mean age of
30 ± 4 ka was determined at Jänschwalde. The succeeding meltdown
during the so-called Frankfurt phase was dated to 26.3 ± 3.7 ka at
Ladeburg. The subsequent landscape stabilization phase started at around
24 ± 2 ka in central Brandenburg, which was deduced by recalibrated
exposure ages of glacigenic boulders (Hardt et al., 2016). These ages are
corroborated by other published OSL ages from the region (Fig. 1).
The recalibration of previously published cosmogenic exposure ages from
glacigenic boulders with an up-to-date 10Be production rate (Heyman,
2014) resulted in a considerable increase of the ages (9–15 %; Hardt
and Böse, 2017). In combination, the OSL ages and the cosmogenic nuclide
exposure ages now provide a consistent geochronology of the Weichselian
ice dynamics in Brandenburg. The largest Weichselian ice extent during the
late marine isotope stage 3 (Brandenburg phase) corresponds with the
so-called Klintholm advance in Denmark (Houmark-Nielsen, 2010) and a
possible ice advance in central Poland (Marks, 2012).
In the area of the supposed Frankfurt ice marginal position on the Barnim
plateau (a till plain to the north of Berlin), we detected a series of ice
marginal fans by analysis of a high-resolution lidar (light detection and ranging) digital elevation model. These arcuate, parallel landforms rise up
to 10 m from the surroundings and extend up to 15 km in length and up to 1.5 km in width. Outcrop studies, geophysical investigations (electrical
resistivity tomography) and map interpretation revealed that the ice
marginal fans consist of diamictic material (Hardt et al., 2015).
OSL dating of glaciofluvial deposits beneath and above one of the structures
revealed that their formation took place in the Frankfurt phase (26 ± 4 ka; Hardt et al., 2016), during the successional downwasting of
the ice after the Brandenburg phase.
The data are publicly available via the thesis and the references therein.
The author declares that he has no conflict of interest.
References
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marginal position south of the Baltic Sea: A critical review of morphological
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Hardt, J., Hebenstreit, R., Lüthgens, C., and Böse, M.:
High-resolution mapping of ice-marginal landforms in the Barnim region,
northeast Germany, Geomorphology, 250, 41–52, 2015.
Hardt, J., Lüthgens, C., Hebenstreit, R., and Böse, M.:
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