Mindel cold time

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Expansion of the alpine glaciation. Blue: Ice rim location in the Mindel and Riss Ice Age, pink: Würm Ice Age

The Mindel glacial period (also Mindel glacial , Mindel complex and colloquially the Mindel glacial period ) is the fourth oldest glacial period in the Alps , if one considers the four glacial periods named by Albrecht Penck and Eduard Brückner (Günz, Mindel, Riß and Würm -Cold period) the preceding earlier Danube and Biber cold periods are added. Penck and Brückner named this glacial period after the Swabian river Mindel . The Mindel glacial period took place in the Middle Pleistocene and was preceded by the Haslach-Mindel interglacial as a warm period . The warm period following the cold period was the Mindel-Riss interglacial , which corresponds to the Holstein warm period in the Baltic Sea region .

Dating and structure

According to the first description in the type region of the Riss - Iller-Lech-Platte, the Mindel glacial period comprises the so-called high or old terminal moraines by Penck and Brückner and the lower or younger ceiling gravel . In this region, the Mindel glacial period was described using the Unterburg-Erliser gravel and the Kirchheim-Burgauer gravel in the Mindeltal. The first description also includes the Sannheim-Laupheimer gravel , the gravel of the Grönenbacher Feld and the Schwaighauser gravel in the Günztal . In the past, part of the gravel in the Swabian foothills of the Alps was called the old crack .

The Mindel glacial period is presumably to be placed in the oxygen isotope level  (MIS) 12, so it would have an age of around 460,000 to 400,000 years ago. Regardless of the absolute dating , the Mindel glacial period is correlated with the north German Elster glacial period , which replaced the long period of the Cromer complex (the Günz glacial period is parallelized as one of the phases of this complex).

The name Mindel is not clear. On the one hand, the third last Vergletscherungsereignis is meant at caused by glaciers erosion can be detected. This event is equated with MIS 12 and the Elster Glaciation , it corresponds to the Great Helvetic Glaciation , the Hoßkirch Glacial and the glacier forms that can be detected in the Inn - Salzach area , which are classified as Mindel. On the other hand, it refers to the occurrence of gravel , which is attributed to the Mindel by interpreting the sequence of the river terraces occurring in the terrain (terrace stratigraphy ), but which are assigned a higher age than the equation of the glaciation event with the Elster glacial period and the MIS is 12.

The demarcation problems between the terrace gravel classified as Haslach and the Mindel gravel in the type area as well as the uncertainty of the connection between the Haslach gravel and glacier deposits have led to the fact that, based on the name of the Cromer complex, for the entire sequence of the Haslach and Minelas terrain forms and deposits the designation Haslach-Mindel complex was proposed. The Haslach-Mindel interglacial can then be seen as one of the several interglacials in this complex, for example, three very clear terminal moraine lines are dated as Mindel (in the broader sense with any Haslach) for the Traunsee glacier .

The classification in the model of the glacial series , which in many cases is well documented in the younger glacial periods, is only possible in a few places in the case of the gravel from the early glacial periods . The deposition of the gravel is probably primarily controlled by tectonic processes such as an uplift phase in the Alps, but a climatic influence is assumed at least for parts of the gravel sequence.

Occurrence

The Mindel glacial period in the area of ​​the Iller glacier can be clearly demonstrated . The Iller Glacier reached its peak during the Mindel, leaving behind the moraine wall of the Holzheuer Höhe , which is paralleled with the Kirchheim-Burgau gravel . Three glacier advances ( stadials ) can be detected here based on the meltwater deposits . The Wertach-Lech glacier also had its peak in the Mindel. The Inn-Chiemsee glacier as well as the Isar-Loisach glacier penetrated about as far into the foreland during the Mindel glacial period as during the subsequent Riß glacial period . The moraine deposits that extend furthest into the foreland are also placed in the Mindel in the area of ​​the Rheingletscher . Here, the gravel of the Mindel glacial period is characterized by a high proportion of crystalline rubble, which can be traced back to the Lower Eastern Alps . The Salzach Glacier and the Dachstein Glacier were about as strong in the Mindel time as in the Günz time and somewhat stronger than in the Riss time, the latter pushed each time up to the Hausruck-und-Kobernaußerwald-Zug ( Subalpine Molasse ). In the Traun-Enns area, however, Günz before Mindel has been found again, east of Linz near Enns the mighty debris from the Günzzeit reach the Danube, the much weaker ones from the Mindelzeit only reach Enns. The Steyr-Krems-Glacier advanced as far as Kremsmünster, the Enns Glacier no longer reached the edge of the Alps. The closed ice current cover ended here, towards the east only local glaciers can be assumed. The later ice ages are much weaker here.

See also

literature

  • KA Habbe, with the collaboration of D. Ellwanger and R. Becker-Haumann: Stratigraphic terms for the southern German Alpine foothills . In: T. Litt on behalf of the German Stratigraphic Commission 2007 (Ed.): Ice Age and Present / Quaternary Science Journal . tape 56 , No. 1/2. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), ISSN  0424-7116 , p. 66-83 .
  • T. 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 ] Explanations and deuqua.de [PDF; 182 kB] table).
  • Albrecht Penck , Eduard Brückner : The Alps in the Ice Age . three volumes, 1901–1909. CH Tauchnitz, Leipzig.

Individual evidence

  1. ↑ Global chronostratigraphical correlation table for the last 2.7 million years. (PDF; 433 kB), correlation table of the Subcomission on Quaternary Stratigraphy of the ICS with the oxygen isotope levels from MIS 106. Version 2009.
  2. ↑ a b Habbe 2007 , p. 75.
  3. ^ Hermann Kohl: The Ice Age in Upper Austria. Part II: The Ice Age glaciation in Upper Austria. In: Yearbook of the Upper Austrian Museum Association. 143a (1998), Chapter 10 The spatial and temporal course of the Ice Age glaciation in Upper Austria. Mindel moraines section . P. 380 f ( landesmuseum.at , [PDF; 52.6 MB]; full article p. 175–390, here p. 213 f).
  4. ^ Walter Freudenberger and 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 .
  5. ^ Eduard Stummer: The interglacial lakes of Salzburg. In: Negotiations of the Federal Geological Institute. 1936, p. 105 ( landesmuseum.at [PDF], full article, p. 101–107);
    Geological map of Salzburg. 1: 200,000. Explanations. (2009), 26, 25, 24 advance gravel; Ground and terminal moraine; Older slab gravel [Mindel] ( Memento from October 17, 2014 in the Internet Archive ) (geomap.geolba.ac.at).
  6. ↑ 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 .
  7. ^ A b c Hermann Kohl: The Ice Age in Upper Austria Part II: The Ice Age glaciation in Upper Austria . In: Yearbook of the Upper Austrian Museum Association. Volume 143a, Linz 1998, especially chap. 10 The spatial and temporal course of the Ice Age glaciation in Upper Austria , p. 376 ff, full article p. 175–390, PDF on ZOBODAT