Würm glaciation
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The Würm glaciation or Würm stage (
The Würm ice age can be dated to about 115,000 to 11,700 years ago. Sources differ about the dates, depending on whether the long transition phases between the
Corresponding glaciations worldwide
The corresponding ice age in North and Central Europe is known as the Weichselian glaciation, after the German name for the Vistula river. Despite the global changes in climate that were responsible for the major glaciations cycles, the dating of the Alpine ice sheet advances does not correlate automatically with the farthest extent of the Scandinavian ice sheet.[4][5] In North America the corresponding "last ice age" is called the Wisconsin glaciation.[6]
Temporal classification
In the
Glaciers repeatedly advanced from the Alps to the northern molasse foreland and left moraines and meltwater deposits behind that are up to several hundred metres thick. Today, the Pleistocene epoch in the Alps is divided into several phases: the Biber, Danube, Günz, Haslach, Mindel, Riss and Würm glaciations. The greatest ice advance into the Alpine Foreland took place during the Riss glaciation, cf. the Saale glaciation in northern Europe.
The most recent foreland glaciation, the Würm, did not have such an extensive and solid glacial front. Nevertheless, its terminal moraines, which indicate the perimeter of the ice sheet, extend as a single tongue well into the foreland. Whilst they were hemmed in by the high mountainsides of the Alps, once these rivers of ice entered the foreland they often combined to form huge glaciers.
The moraines and gravel beds formed in the Würm glaciation are the best preserved, because since then there have been no more similar geological processes. Traces of the ice sheet have not been scoured out by later glaciers or overlaid by their sediments. This allows a more precise dating for the Würm glaciation than for earlier ice ages.
The Würm glaciation was preceded by the
The Würm Glacial ended around 11,700 years ago with the beginning of the Holocene. The cold period was followed by another warming which continues today and during which the glaciers are retreating. However, even in the Holocene there have been variations in temperature and ice advances, the last one in the modern era being the so-called Little Ice Age. The Holocene is considered an "interglacial" of a larger ice age, since the poles and the high mountain areas are still glaciated.
See also
References
- ISBN 0-14-051094-X.
- ISBN 978-3-931516-09-3
- ISBN 978-3-931516-09-3
- ^ Sibrava, V., Bowen, D. Q, and Richmond, G. M.: Quaternary Glaciations in the Northern Hemisphere, Quaternary Science Reviews. vol. 5, 1986, pp. 1–514
- ISBN 3-8062-1734-3
- ISBN 0-444-51462-7
Sources
- Roland Walter: Geologie von Mitteleuropa. Schweizerbartsche Verlagsbuchhandlung, Stuttgart, 1992, ISBN 3-510-65149-9
- René Hantke: Eiszeitalter. Band 2: Letzte Warmzeiten, Würm-Eiszeit, Eisabbau und Nacheiszeit der Alpen-Nordseite vom Rhein- zum Rhone-System. Ott, Thun, 1980, ISBN 3-7225-6259-7
- Hans Graul, Ingo Schäfer: Zur Gliederung der Würmeiszeit im Illergebiet. Straub, Munich, 1953. (Geologica Bavarica, 18).
- Wolfgang Frey, Rainer Lösch: Lehrbuch der Geobotanik, Pflanze und Vegetation in Raum und Zeit. Elsevier Spektrum Akademischer Verlag, ISBN 3-8274-1193-9
- Dirk van Husen: Die Ostalpen in den Eiszeiten, Aus der Geologischen Geschichte Österreichs, Geologische Bundesanstalt Wien, ISBN 3-900312-58-3
- Rolf K. Meyer, Hermann Schmidt-Kaler: Auf den Spuren der Eiszeit südlich von München – östlicher Teil, Wanderungen in die Erdgeschichte, Vol. 8, ISBN 978-3-931516-09-3
External links
- Karte: "Umwelt, Biologie und Geologie: lastiszeitliches Maximum". map.geo.admin.ch. swisstopo. Retrieved 2011-12-12.