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| Titel |
Late Quaternary ice sheet extents in northeastern Germany inferred from surface exposure dating |
| VerfasserIn |
Vincent Rinterknecht, Régis Braucher, Margot Böse, Didier Bourlès, Jean-Luc Mercier |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250043603
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| Zusammenfassung |
| We determined in situ cosmogenic 10Be ages for 11 boulders on the Hoher Fläming ice
marginal belt and 5 boulders on the Gerswalder Moraine, a recessional moraine of the
Pomeranian Phase in northeastern Germany. Samples were processed and analysed at the
Laboratoire National des Nucléides Cosmogéniques, France. Surface exposure ages were
calculated using the CRONUS-Earth online 10Be exposure age calculator and a constant
production rate model. No corrections were made for erosion or possible snow
cover.
Previous time estimations for the deposition of these moraines along the southern margin
of the Scandinavian Ice Sheet (SIS) are mostly based on geomorphology and stratigraphy,
and on few radiocarbon dates and three recently published surface exposure ages (using
cosmogenic 10Be) in the case of the Pomeranian Phase.Â
Our new exposure ages range from 21.2 ± 1.6 10Be ka to 136.1 ± 7.4 10Be ka for the
Hoher Fläming ice marginal belt. The wide range of exposure ages may reflect
episodic ice marginal belt modification due to intensified erosion by meltwater
channeled in the Baruther Urstromtal, accompanied by long-lasting denudation
processes like solifluction and aeolian deflation. For the Gerswalder Moraine, our
exposure ages range from 12.0 ± 0.7 10Be ka to 15.5 ± 1.1 10Be ka. Excluding the
youngest sample (BER-97-03), we calculated an error-weighted mean age of 14.9 ±
0.6 10Be ka (n = 4), in good agreement with previously published data. These
results further establish the position of the southern margin of the SIS in northeastern
Germany during the Gerswalder phase a recessional phase of the Pomeranian Phase. |
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