Rift Cold Age

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Expansion of the Mindel and Riss icing (blue) compared to the extent of the ice during the Würm cold time

The crack-cold period (also crack glacial , crack complex or outdated crack ice age ) is in the traditional four-membered cold period scheme of Alps , the second youngest cold period of the Pleistocene the Alps . Depending on the literature, their period is dated around 300,000 to 130,000 years or 347,000 to 128,000 years before today (in northern Germany as the Saale glacial period ). The name goes back to Albrecht Penck and Eduard Brückner , who named this cold period in their three-volume work The Alps in the Ice Age after the river Riss in Upper Swabia , published between 1901 and 1909 .

Delimitation and structure

Penck and Brückner defined the Riss glaciation as lower or younger old moraines and old end moraines - high terraces . The type locality is near Biberach an der Riß in the area of ​​the outer north-eastern Rhine glacier . The knowledge gained after more than a century of research shows that several ice advances took place in almost all cold ages. In total, at least eight to 15 ice advances are expected in the Alpine region today. Several ice advances also took place in the Riss Ice Age, so that it is structured by interstadials (ice retreats) and stadials (ice advances) and at least one previously unnamed warm period.

The current structure differs from the original Penck structure. According to the Stratigraphic Table of Germany 2002, the beginning of the Riss Ice Age is the end of the Holstein Warm Age (in the Alpine foothills Mindel-Riss Interglacial , corresponds to the names Samerbe , Thalgut , Praclaux and La Côte ); its end is the beginning of the Eem- Warm period (Riß-Würm interglacial), it is thus roughly the same time as the Saale glacial period of the northern German glacial division. The Riss glaciation is paralleled with the MIS 6, 8 and 10 and would thus be classified between 350,000 and 120,000 years before today. The so-called Older Riss , the time of the furthest ice advances in the Alpine region, was separated from the Riss Cold Age: today it is known as the Haslach-Mindel complex (in Bavaria and Austria), the Hoßkirch complex (in Baden-Württemberg) or the largest glacier in in Switzerland.

The structure of the cold periods in Switzerland is different from the structure used in the Bavarian and Austrian Alpine foothills. The glacial complex between the end of the Holstein warm period and the beginning of the Eem warm period is called the penultimate ice age and the great glaciations . It is structured by two additional interstadials, the so-called "double Holstein occurrence of Meikirch", which are not, however, identical to the Holstein warm period.

Alpine Riss Ice Age (in the north: Saale Ice Age) compared to the later Würm Ice Age (in the north: Vistula Ice Age). During the maximum glaciation, the archaic humans ( Homo heidelbergensis - later the Neanderthals ) retreated behind the permafrost limit, in the warmer periods they spread over this to the north and northeast. Only during the Weichsel-Würm Ice Age did people settle from around 40,000 BC. The modern Cro-Magnon man these areas.

Course and extent of the crack cold time

At the beginning of the Riss Ice Age, almost all of today's river valleys were created. The glaciation of the Alps had already led to the glaciers advancing far into the foothills in several phases, further than any known advances, and the main glaciers along the current river valleys had established themselves before the Holstein warm period towards the end of the greatest glaciations. During the Riss Ice Age, the glaciers in the Bavarian and Austrian Alpine foothills probably advanced four times. The first two advances have not been confirmed with certainty, as they are overlaid by the two stadials at the end of the Riss glaciation, which extended very far to the north.

The ice advances of the Cold Age mostly went well beyond the tongue basins of the previous glaciers. In most areas of the tear-terminal moraines are designed as low wall, for example in the area of the Inn Glacier , the Isar-Loisach glacier , the Iller glacier and in the area of the western Rhine glacier . In the type of region in Biberach another notable, rather atypical Doppelmoränenwall, just not typical here is a double terrace, which probably increased erosion during occurred in the Riss glaciation relocation of meltwater runoff from the Wellheimer Arroyo and the Altmühltal in today's Danube Valley is due . The double wall of the type region ( double wall crack , with an outer wall and an inner wall ) shows the subdivision of the Riss ice age into at least two stages through the formation of two superimposed sequences of glacier deposits.

In the west the Rhone glacier covered large parts of the Swiss plateau , in the north it reached the northern Jura folds and in the south Lyon . To the northeast, it merged into the Linth Glacier and the Reuss - Aare Glacier without any sharp demarcation , only the Napf region remained ice-free. Further to the northeast, the Reuss-Aare glacier was not separated from the Rhine glacier. This stretched north to over today's Danube in the area of ​​the Swabian Alb . In Bavaria, the Riss moraines form a poorly subdivided landscape without bogs and lakes if they are not covered by more recent deposits from the Würm glacial period . The gravel assigned to the Riss moraines builds today's high terraces of the Danube tributaries.

The Salzach Glacier and the Dachstein Glacier were somewhat weaker at the time of the Riss than in the Günz and Mindel times, the latter pushing each time as far as the Hausruck and Kobernaußerwald train ( Subalpine Molasse ).

literature

  • Karl-Albert Habbe, with the collaboration of Dietrich Ellwanger and Raimo Becker-Haumann: Stratigraphic terms for the Quaternary of the southern German Alpine foothills . In: Thomas Litt on behalf of the German Stratigraphic Commission 2007 (Ed.): Ice Age and Present / Quaternary Science Journal . 56, No. 1/2. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), ISSN  0424-7116 , p. 66-83 , doi : 10.3285 / eg.56.1-2.03 ( article ).
  • Thomas Litt et al .: The Quaternary in the Stratigraphic Table of Germany 2002 . In: Newsletters in Stratigraphy . tape 41 , no. 1-3 . Berlin, Stuttgart, p. 385–399 ( explanations (PDF; 124 kB) and table (PDF; 182 kB)).
  • Albrecht Penck, Eduard Brückner: The Alps in the Ice Age . CH Tauchnitz, Leipzig (1901-1909 in three volumes; 1199 pages).

Web links

Individual evidence

  1. ^ Walter Freudenberger, Klaus Schwerd: Geological map of Bavaria 1: 500000 with explanations. 1 card + explanations + 8 supplements . 4th edition. Bavarian Geological State Office, Munich 1996, p. 238 ff .
  2. ↑ a b Ueli Reinmann: On the trail of the Ice Age in the Wangen a. A. New findings based on soil studies in the terminal moraine area of ​​the Rhone Glacier. In: Yearbook of the Oberaargau . tape 47 , 2004, p. 135–152 ( biblio.unibe.ch [PDF; 12.5 MB ]).
  3. ↑ Thomas Litt et al .: The Quaternary in the Stratigraphic Table of Germany 2002 . In: Newsletters in Stratigraphy . tape 41 , no. 1-3 . Berlin / Stuttgart, p. 385–399 ( deuqua.de [PDF; 124 kB ]).
  4. ↑ Lorraine E. Lisiecki, Maureen E. Raymo: A Plio-Pleistocene Stack of 57 Globally Distributed Benthic δ 18 O Records . In: Paleoceanography . tape 20 , 2005 ( pdx.edu ( Memento from June 16, 2011 in the Internet Archive ) (PDF; 1.1 MB)). A Plio-Pleistocene Stack of 57 Globally Distributed Benthic δ 18 O Records ( Memento of the original from June 16, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / web.pdx.edu
  5. ↑ a b c Roland Walter et al .: Geology of Central Europe . 5th edition. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart 1992, ISBN 3-510-65149-9 , pp. 407 .
  6. ↑ Habbe 2007 , p. 80
  7. ↑ The Quaternary in the Stratigraphic Table of Germany 2002. (PDF; 187 kB) (No longer available online.) Archived from the original on February 16, 2010 ; Retrieved February 14, 2010 (Stratigraphic Table). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.deuqua.de
  8. ^ Eduard Stummer: The interglacial lakes of Salzburg. In: Negotiations of the Federal Geological Institute. 1936, p. 105 (full article p. 101–107, PDF on ZOBODAT , p. 5 there).
  9. ^ Geological map of Salzburg 1: 200,000. Explanations. (2009), 20, 19, 18 advance ballast; Ground and terminal moraine; Hochterrasse [Riss] ( Memento of the original from October 17, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. geomap.geolba.ac.at @1@ 2Template: Webachiv / IABot / geomap.geolba.ac.at
  10. ↑ In the space Straßwalchen about the tear-edge and terminal moraines are the Irrseegletschers at 500- 650  m above sea level. A. , the Mindel moraines at around  700  m . GKÖ 64 Straßwalchen and 65 Mondsee .