Elster Cold Age

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Maximum extent of the ice in Europe
Schematic representation of the maximum glacier advances of the three last glaciers in the north German lowlands:
  • Ice edge of the Vistula glaciation
  • Ice edge of the Saale Glaciation
  • Ice edge of the Elster Glaciation

    • The Elster glaciation , also Elster glacial or Elster-time , in the older and popular science literature Elster glaciation called, is the oldest cold period of the Cenozoic Ice Age , when it is proven to come to a large-scale glaciation in northern Germany. It is chronologically correlated with the southern German Mindel glacial period . The Elster Glaciation is currently dated to around 400,000 to 320,000 years ago. It replaced the long period of the Cromer complex , which was on average somewhat warmer . Two ice advances are widespread. The Holstein warm period follows the Elster cold period .

    Naming and conceptual history

    The Elster Cold Age is named after the White Elster , a right tributary of the Saale . The name was first used by Konrad Keilhack in 1910 as "Elster Ice Age". He did not name a type locality . By resolution of the sub-commission for European Quaternary Stratigraphy, a profile at Voigtstedt ( Kyffhäuserkreis , Thuringia ) was determined for the lecto-stratotype locality. The term "Elster Ice Age" replaced the older term "First Ice Age". Today the terms Elster-Kaltzeit or Elster-Glacial are the most common in scientific literature. However, since the Elster cold period also includes warmer periods, some researchers also speak of the Elster complex. However, Litt et al. (2007) find this term inapplicable and reject the term because the Elster cold period is not divided by any warm period. In the Stratigraphic Table of Germany 2002, the name has been changed to Elsterium in order to align with the chronostratigraphic units.

    Correlation and Dating

    The exact age of the Elster Cold Age is still a matter of dispute today. The reason lies in the lack of absolute dating possibilities for the Ice Age sediments, so that the age information is based on a correlation with the somewhat more recent deposits of the Holstein warm period. But the age of this warm period is still controversial today. Some of the Quaternary geologists still favor the oxygen isotope level (MIS or OIS) 11 for Holstein, while MIS level 7 is currently hardly represented. The methods of age determination improved in the last 10 years, in particular uranium-thorium dating and radiofluorescence as a new method of thermoluminescence dating, make the oxygen isotope level 9.3 most likely today. This means that the Elster glacial period in Central Europe is mostly correlated with the global marine oxygen isotope zone MIS 10 and a period of 400,000 to 320,000 years ago is assumed. If the Holstein were classified in MIS level 11, the Elster glacial period would then be classified in MIS level 12 (peak 430,000 years before today).

    distribution

    Zwickau-Schedewitz, memorial stone for the southern border of the Scandinavian inland ice during the Elster glacial period

    Deposits from the Elster glacial period are widespread in northern and central Germany. The deposits reach up to the maximum extent of the Fennoskand ice sheet , which is marked in Saxony, Saxony-Anhalt and Thuringia by the flint line . The flint from Cretaceous deposits was transported with the ice from northern Europe to southern or central Germany and deposited on the edge of the ice, the terminal moraines. The ice of the Elster glaciation reached the northern edge of the Harz in Germany, ran from there to the southeast and overcame the Lower Harz east of the Bodetal. South of the Harz, the ice turned to the west and penetrated a line from Bad Langensalza-Erfurt-Weimar. From there the edge of the ice can be followed via Jena and Weida to Zwickau. From Zwickau it continued along the Ore Mountains via Chemnitz, Roßwein to Freital, the Elbe Sandstone Mountains and the Lusatian Mountains . To the west of the Harz, the course of the ice edge is well known as far as Seesen, Alfeld and Rinteln. Further to the west it is unsafe because it was run over by the glaciers of the younger Saale glaciation and the terminal moraines were leveled. Using the flint line, however, the position of the edge of the ice can be roughly defined further: along the Teutoburg Forest, after a bend of a few tens of kilometers to the south, further to the northwest north of the Ems to the northern Netherlands and the North Sea.

    Course and structure of the Elster Cold Age

    The border to the older Cromer complex is drawn with a significant cooling after the last interglacial of the Cromer complex. In the lecto stratotype profile, the Elster glacial period is underlain by the Voigtstedt interglacial. However, the limit is extremely problematic. According to Litt et al. (2007) there is some evidence that the Voigtstedt interglacial cannot be correlated with the most recent interglacial of the Cromer complex, but with an older interglacial within the Cromer complex. However, this has made the lower limit of the Elster glacial period defined in Voigtstedt very questionable; a larger layer gap between Voigtstedt interglacial and the Elster glacial period is to be expected.

    In the Elster high glacial , a period of 65,000 years, there were at least two large ice advances, the maximum extent of which reached to the foot of the German low mountain range. The advances are separated from each other by an ice retreat.

    • Markranstädt phase with glacial sediments ( lithostratigraphically called the Markranstädt glacial formation)
    • Miltitz interval, melt water deposits and fluvial deposits (also called "Miltitzer Horizont" or "Miltitzer Zwischen sediment")
    • Zwickau phase (called Erfurt phase in Thuringia), glacial sediments (lithostratigraphically called Zwickau glacial formation)

    In the Elster Late Glacial there was a gradual warming again over a period of around 15,000 years. Three interstadials have been eliminated so far:

    • Esbeck-Interstadial, all three Interstadial are covered with pine, spruce and birch trees.
    • Offleben II-Interstadial
    • Offleben I-Interstadial

    The three interstadials are separated from each other by short stadiums, the Esbeck interstadial is separated from the Holstein warm period by a short stadial. These stadiums have not yet been given their own names.

    In contrast to the later glaciations, the maximum extent is no longer recognizable from terminal moraines . An icing even further south during the later Saale Glacial Period in western Germany erased all traces that could be recognized above ground. The more eastern terminal moraines, which were later no longer formed by ice, were leveled mainly by long-lasting periglacial processes. The extension can be reconstructed using the flint line . In Schleswig-Holstein, subglacial clearings created channels up to −360 m below sea level, which were later filled with younger deposits.

    literature

    Individual evidence

    1. ↑ Litt et al. (2007: p. 27ff)
    2. ↑ Stratigraphic Table of Germany 2002 , German Stratigraphic Commission (DSK), 2002. ISBN 3-00-010197-7 (PDF file; 7 MB)
    3. ↑ Krbetschek, MR, Degering, D. & Alexowsky, W .: Infrared-Radiofluorescence-Age (IR-RF) Sub -Saale-Age sediments of Central and Eastern Germany. Journal of the German Society for Geosciences, Volume 159/1, 2008. P. 141 ff.
    4. ↑ Mebus A. Geyh, Helmut Müller (2005): "Numerical 230 Th / U dating and palynological a review of the Holsteinian / Hoxnian interglacial". In: Quaternary Science Reviews 24 (16-17): 1861-1872. doi : 10.1016 / j.quascirev.2005.01.007