Wirkungen des pleistözänen kaltzeitlichen Klimas, insbesondere des Bodenfrostes, in den Sedimenten des östlichen Ostfalen (Eiskeile, Löß-Flugsand, asymmetrische Täler)
| Autor: | K.-U. Brosche |
|---|---|
| Jazyk: | German<br />English |
| Rok vydání: | 1997 |
| Předmět: | |
| Zdroj: | Eiszeitalter und Gegenwart, Vol 47, Pp 89-106 (1997) |
| Druh dokumentu: | article |
| ISSN: | 0424-7116 2199-9090 |
| DOI: | 10.3285/eg.47.1.05 |
| Popis: | In the second part of the article with the title "Wirkungen des ..." a various documentation of pictures is presented to analyse the ice-wedge casts of the eastern part of Lower Saxony (Ostfalen). These structures are the only periglacial phenomena, which represent doublessly a former permafrost soil. After a short introduction, in chapter 2 Saalian or probably older nets of ice-wedge casts are documentated, which reach in a depth of 6 m in Ahlum (east of Wolfenbüttel) and which can be dated very well using their content of sediments and their cover sediments. In Barmke (nr. 12, fig. 1) there were found normal ice-wedge casts and former ice-vains and "Eisgänge" (fig. 2), which posess a Saalian or older age. - The ice-wedge casts with a length of 2,0 to 2,5 m, which were formed in one continuing phase are all of Weichselian age. - In some exemples polygenetic ice-wedge casts could b e found, which grew either during the Saalian (or the Elsterian) or - in other examples - during the Saalian and Weichselian time. - In chapter 5 some „Kleinkeile" and „Kissenböden" with little syngenetic frost fissures are presented, which are not due to a permafrost soil, but are formed by a frost soil during a stadial or interstadial phase within the Weichselian (fig. 14 and 15). - A sequence of a yellow loess in alternation with sand layers from the Eocene formation, which was a great exception, was presented from the northern loess border (fig. 16). - Only two climatic asymmetric valleys could be found, which were developed since the Saalian ice left our landscape. - All described forms were developed in sediments of the Quaternary or in sands and clay of the Tertiary. Only some ice-wedge casts were formed in marls and clay of the Keuper. - Syngenetic cryoturbation forms and ice-wedge casts could only b e found in the Oker-Mittelterrasse (fig. 18). - Climatic conclusions for the coldest times of the Weichselian and Saalian time were made: at least a temperature depression of 14 to 15° could be found. |
| Databáze: | Directory of Open Access Journals |
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