Vistula glacial period
| Stadiale /
|Vistula late glacial|
|Younger dryas period||10,730-9,700|
|Older dryas period||11,590-11,400|
|Oldest dryas period||11,850-11,720|
|Vistula high glacial|
|Vistula early glacial|
|Eem warm period|
As Weichselian , Weichselian or Vistula complex is the last glaciation of the Cenozoic Ice Age called and the associated glaciation of northern Europe and northern Central Europe. Colloquially it is also known as the Vistula Ice Age or the Vistula Period , whereas in the Alpine region it is called the Würm Ice Age . It was characterized by a large ice sheet that started from the Scandinavian high mountains and extended to the east coast of Schleswig-Holstein, into the Brandenburg region and to northern Russia.
In northern Europe it was the youngest of the glacier phases ( glacials ) in the Pleistocene . The previous warm period is called the Eem warm period in the same area . The last glacial period began around 115,000 years ago and ended 11,600 years ago. According to the international classification, which is based on the oxygen isotope levels , the last great glaciation ( English Last glacial period ) begins in the MIS 5d level and ends with the MIS 2 isotope level. With its end, the Pleistocene ends and the Holocene begins .
Designation for other regions
In other areas, the glaciations of the last glacial period are referred to by other names: For example, one speaks of the Würm glacial period in the Alps , and of the Devensian glaciation in the British Isles ( Devenses ice age , from Latin Dēvenses , "people who live on the river Dee Live ") and in North America from the Wisconsin Glaciation .
Naming and conceptual history
It is named after the Vistula River in Poland . The name "Vistula Ice Age" probably goes back to a suggestion by Konrad Keilhack . From 1909 the name was used at the Prussian Geological State Institute . The type region is the lower Vistula valley, a type locality has not been specified. Today the term Vistula Glacial or Vistula Glacial has established itself. Since the actual "Ice Age" (ie glacier advances as far as northern Germany) only takes up a small part of this period, some researchers prefer the term Vistula Complex. In the Stratigraphic Table of Germany 2002, the Weichselian glacial period is modified to Weichselium in order to align it with the names of the chronostratigraphic units.
Course and structure of the Vistula glacial period
About 115,000 years ago the average temperatures dropped significantly and the heat-loving forest communities were displaced. With this clear cut in the average temperatures, the Eem warm period ended and the Vistula glacial period began. It is divided into three sections according to the temperature profile: the Vistula Early Glacial, the Vistula High Glacial (also Vistula Pleniglacial) and the Vistula Late Glacial. During the Vistula Glacial Period, violent climatic fluctuations took place in the northern hemisphere, the so-called Dansgaard-Oeschger events .
The Vistula Early Glacial (115,000 - 60,000 BC) is in turn divided into four stages:
- Odderade-Interstadial (WF IV). The pollen spectra suggest a boreal forest. It begins with a tree birch phase that quickly turns into a pine forest. Larchs and spruces are also proven, as well as alder trees to a very small extent .
- Rederstall-Stadial (also WF III). In Northern Germany, the pollen spectra indicate a grass tundra with later strauchtundra.
- the Brörup-Interstadial (also WF II). In some profiles there is a short cooling phase shortly after the start of the Brörup interstadial, but this is not detectable in all profiles. This caused some authors to separate the first warm phase as the Amersfoort Interstadial. In the meantime, however, this first warming and cooling phase is included in the Brörup Interstadial. Northern Central Europe was overgrown with birch and pine forests. The Brörup Interstadial is identified with the marine oxygen isotope level 5c.
- the Herning-Stadial (also called WF I) was a first cold phase in which northwestern Europe was largely unforested. It corresponds to the marine oxygen isotope level 5d.
In the Vistula High Glacial (57,000 - approx. 15,000 BC) the glaciers advanced as far as northern Germany. However, some interstadials are documented at the base.
- Glaciation and ice advances as far as northern Germany ( Brandenburg phase , Frankfurt phase , Pomerania phase , Mecklenburg phase ).
- Denekamp-Interstadial. The pollen spectra indicate a strauchtundra.
- Hengelo Interstadial. The pollen shows sour grass plants (Cyperaceae) and temporarily high levels of dwarf birch ( Betula nana ).
- Moershoofd Interstadial. The pollen spectra show a treeless tundra vegetation with high proportions of sour grass plants (Cyperaceae).
- Glinde Interstadial (SS IV). The pollen diagram suggests a treeless tundra.
- Ebersdorf Stadium (SS III). In northern Germany, this period is characterized by pollen-free sand.
- Oerel-Interstadial (WP II). The pollen diagrams indicate a tree-free strauchtundra in northern Germany.
- Schalkholz Stadium (SS I). A first ice advance could have already reached the southern Baltic coast. At the type locality Schalkholz (district of Dithmarschen ), pollen-free sand documents a largely vegetation-free landscape
The short Vistula Late Glacial (12,500 - approx. 10,000 BC) is the phase of slow warming after the Vistula High Glacial. But it is again interrupted by some rather cool phases.
- Younger dryas period . During this time, the proportion of non-tree pollen rose again, especially that of sun plants .
- Alleröd Interstadial . This section is again dominated by birch pollen.
- Older dryas period . This cool period is marked by a decline in tree pollen.
- Bölling-Interstadial . This section begins with a rapid increase in tree birch pollen.
- Oldest dryas period . This cool section is characterized by a maximum of non-tree pollen.
- Meiendorf-Interstadial . This interstadial is characterized by an increase in pollen from dwarf birch ( Betula nana ), willow ( Salix sp.), Sea buckthorn ( Hippophae ), juniper ( Juniperus ) and Artemisia .
After the last of these temperature drops, the “Younger Dryas Period”, the Vistula glacial ended with an abrupt rise in temperature approx. 9,660 ± 40 BC. BC At the same time, today's interglacial , the Holocene, began .
In addition to the above classification, the deposits of the Vistula Late Glacial are divided into four stages according to the state of the ice retreat: Germaniglacial (Germany becomes ice-free), Daniglacial (Denmark becomes ice-free), Gotiglacial (Gotland becomes ice-free) and Finiglacial (Finland and Norway become ice-free) .
Expansion of the ice sheet
The extent of the Fennoskand Ice Sheet was significantly smaller in the Vistula Glaciation compared to the older glacial ages ( Elster and Saale Glaciers ). In Germany, the maximum ice advance of the Vistula glacial ended roughly at the line of today's cities of Flensburg , Rendsburg , Hamburg , Ahrensburg , south of Schwerin , Havelberg , Brandenburg an der Havel , Luckenwalde , Lübben and Guben , i.e. within the north-east German lowlands. The Elbe and the warthestadiale ( Saale Cold Age ) southern ridge were not crossed by the Weichselian inland ice, they were subject to periglacial influence due to the formation of low terraces and upwelling of inland dunes and loess during this time .
Structure of the ice advances
During the high glacial ice age of the Vistula there were three or four major advancing phases of the ice in northern Germany. Each advance phase left behind a group of terminal moraines , a so-called relay . Each of the stadiums has deposited its own till .
During the Brandenburg phase , the ice reached its maximum extent (south the Glogau-Baruther glacial valley and northwards following the Potsdam glacial valley upstream). This line is also known as the Brandenburger Eisrandlage . The Frankfurter Staffel , which runs northeast of Berlin and does not have its own marl, also belongs to the Brandenburg Stadium .
The second major advance phase is the Frankfurt phase . It is often not separated from the Brandenburg phase in the older literature.
The fourth major advance, the Mecklenburg Stadium with the Rosentaler relay , only reached Mecklenburg-Western Pomerania . How far the ice sheet melted back to the north between the individual stages is still controversial.
Landscape in the icing area
This last glacial period left behind a diverse young moraine landscape due to the advancement and retreat of the ice . Typical for this are the fresh, well-developed forms of the glacial series . These include the glacial valleys with valley sand areas, in which sections of today's rivers of the Elbe , Oder , Havel and Spree are located. Mention should be made of the Glogau-Baruther glacial valley , which drained the Brandenburg ice rim , the Warsaw- Berlin glacial valley with the associated Frankfurt Staffel and the Thorn- Eberswalder glacial valley , which drained the Pomeranian ice rim .
Another relic from that time is the lake landscape of the Mecklenburg Lake District . Also, Brandenburg and Schleswig-Holstein hills (u. A. Ostholstein ) are rich in weichselglazialen lakes, such as the Ploen Lake in the Holstein Switzerland . Some lakes such as the Schweriner and Ratzeburg lakes were created in glacier tongue basins , as well as some fjords .
The Baltic or Northern Ridge is another example of the treasure trove of forms left by the Vistula glaciation . It consists of lively structured terminal moraine walls, often staggered one behind the other, and accompanies today's Baltic Sea coast to northern Poland. In Pomerania and Mazury , heights of over 300 m above sea level are reached in places, for example at Wieżyca , south-west of Gdansk 329 m and 312 m south of Ostróda . The highest elevations from the Pomeranian Stadium are the Helpter Mountains in the German part of the Northern Ridge . They reach a height of 179 m southeast of Neubrandenburg in Mecklenburg-Western Pomerania.
The end of the Vistula cold season
The end of the most recent cold period in Central Europe is marked by the gradual retreat of the ice edge to the north. As the ice melted, the sea level, which had previously fallen sharply, rose again, by a total of around 120 meters from an absolute low around 22,000 years ago. In a complicated interplay of ice reservoirs and sea advances, today's Baltic Sea was formed over several stages such as the Ancylussee with the Baltic Ice Reservoir , the Yoldia Sea and the Littorina Sea . The retreat of the ice was followed by repopulation by plants and animals. With their north migration various settlement waves of hunter and gatherer cultures went hand in hand.
- Thomas Litt, Karl-Ernst Behre, Klaus-Dieter Meyer , Hans-Jürgen Stephan, Stefan Wansa: Stratigraphic terms for the Quaternary of the northern German glaciation area . In: T. Litt on behalf of the German Stratigraphic Commission (ed.): Stratigraphie von Deutschland - Quaternary. Special issue. Ice Age and Present / Quaternary Science Journal . 56, No. 1/2. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), 2007, ISSN 0424-7116 , p. 7-65 , doi : 10.3285 / e.g. 56.1-2.02 .
- Herbert Liedtke, Joachim Marcinek : Physical geography of Germany. Justus Perthes Verlag, Gotha 1995, ISBN 3-623-00840-0 .
- Thomas Litt, Achim Brauer , Tomasz Goslar, Josef Merkt, Krystyna Bałaga, Helmut Müller, Magdalena Ralska-Jasiewiczowa, Martina Stebich, Jörg FW Negendank: Correlation and synchronization of Lateglacial continental sequences in northern central Europe based on annually laminated lacustrine sediments. In: Quarternary Science Reviews. vol. 20, No. 11, May 2001, pp. 1233-1249.
- For the sake of standardization, the age data for the climatic stages of the Vistula Late Glacial were converted to v. With the dendrochronological and warven chronological data, the reference point is the year 1950, ie 1950 years have to be subtracted to get BC. Chr. Indications to receive. The ice core data, on the other hand, relate to the reference year 2000. The age information from the Vistula high glacial is the approximate start of the corresponding time interval vh
- T. Litt among others: Stratigraphic terms for the Quaternary of the north German glaciation area. 2007, p. 45ff.
- Devensian - lexico.com. Retrieved April 23, 2020
- Stratigraphic table of Germany 2002. German Stratigraphic Commission (DSK), 2002, ISBN 3-00-010197-7 . (PDF file; 7 MB)
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- Karl N. Thome: Introduction to the Quaternary. The age of the glaciers . Springer-Verlag, Berlin 1998, p. 72 ( p. 72 in Google Book search).
- Rudolf Hohl (ed.): The history of the development of the earth. 6th edition. Werner Dausien Verlag, Hanau 1985, ISBN 3-7684-6526-8 , p. 410ff.
- Eckart Schmitt among other things: Harms Handbuch der Geographie - Germany. 26th edition. Paul List Verlag, Munich, ISBN 3-471-18803-7 , 1975, p. 70.
- Kevin Fleming, Paul Johnston, Dan Zwartz, Yusuke Yokoyama, Kurt Lambeck , John Chappell: Refining the eustatic sea-level curve since the Last Glacial Maximum using far- and intermediate-field sites. In: Earth and Planetary Science Letters. 163 (1-4), 1998, pp. 327-342. doi: 10.1016 / S0012-821X (98) 00198-8