Pleistocene climate characteristics in the most continental part of the northern hemisphere: insights from cryolithological features of the Batagay mega thaw slump in the Siberian Yana Highlands
Syngenetic permafrost deposits formed extensively on and around the arising Beringian subcontinent during the Late Pleistocene sea level low stands. Syngenetic deposition implies that all material, both mineral and organic, gets frozen parallel to sedimentation and remains frozen until degradation o...
| Main Authors: | , , , |
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| Format: | Article in Journal/Newspaper |
| Language: | unknown |
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COPERNICUS GESELLSCHAFT MBH
2016
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| Subjects: | |
| Online Access: | https://epic.awi.de/id/eprint/41971/ https://hdl.handle.net/10013/epic.48790 |
| Summary: | Syngenetic permafrost deposits formed extensively on and around the arising Beringian subcontinent during the Late Pleistocene sea level low stands. Syngenetic deposition implies that all material, both mineral and organic, gets frozen parallel to sedimentation and remains frozen until degradation of the permafrost. Permafrost is therefore a unique archive of late Pleistocene paleoclimates. Most studied permafrost outcrops are situated in the coastal lowlands of NE Siberia and are 15 thus under certain influence of today’s rather maritime climate. Permafrost sections more inland are in contrast scarcely available. Here we describe the cryolithological and geochronological characteristics of a permafrost sequence near Batagay in the Siberian Yana Highlands, the interior of the Republic Sakha (Yakutia), Russia. The recently formed Batagay mega thaw slump exposes permafrost deposits to a depth of up to 80 m and gives insight into a sought climate record close-by the Pole of Cold - the place with the most severe continental climate of the Northern Hemisphere. We provide a detailed 20 stratigraphic description of this profile and present results of cryolithological and geochemical analyses to deduce the genesis of the permafrost sequence, which comprised, according to our observations and sedimentological results, five lithological units. Geochronological dating (OSL and 14C ages) and stratigraphic implications delivered a temporal frame from the Middle Pleistocene to the Holocene for our sedimentological interpretations and also revealed interruptions in the deposition of the sequence. The sequence of lithological units indicates a succession of several distinct climate phases: a middle 25 Pleistocene Ice Complex indicates cold stage climate conditions resulting in a mean annual ground temperature at least 8 °C lower than today; then, ice wedge growth stopped due to highly increased sedimentation rates and eventually a rise of temperature; full interglacial climate conditions existed during accumulation of an ... |
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