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Climate of the Past An interactive open-access journal of the European Geosciences Union
https://doi.org/10.5194/cpd-9-6255-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
08 Nov 2013
Review status
This discussion paper has been under review for the journal Climate of the Past (CP). A final paper in CP is not foreseen.
Onset of intense permafrost conditions in Northern Eurasia at ~2.55 Ma seen in a cryogenic weathering record from Lake El'gygytgyn
G. Schwamborn, L. Schirrmeister, and B. Diekmann Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Potsdam, Germany
Abstract. Physical weathering in permafrost landscapes contrasts to mid- and low latitude physical weathering in the way that quartz is less stable in freeze–thaw (F/T) cycles and breaks down to silt sized grains. F/T weathering also produces a distinct single quartz grain micromorphology such as microcracks and brittle textures of the surface. Both of these sediment-mineralogical features have been used for identifying intense permafrost conditions (i.e. intense F/T dynamics) around Lake El'gygytgyn in NE Eurasia using a Pliocene–Pleistocene sediment record from the centre of the lake. This lake provides the longest terrestrial palaeoenvironmental archive in the Arctic and has been a sediment trap for 3.6 Ma. Detritic material marked by F/T weathering becomes distinctive ~2.55 Ma ago and has been accumulating since then in the lake basin. This time marker coincides with the establishment of a perennial lake ice cover and corresponds with pollen assemblages indicating a significant cooling during that time. It matches fairly well the timing of the Plio-/Pleistocene cooling known from other marine and terrestrial evidence.

The onset of intense quartz weathering is regarded as a first order age assessment for the beginning of persistent Quaternary permafrost conditions and which deepened into the ground since then in settings of high continentality in the non-glaciated NE Eurasian Arctic.


Citation: Schwamborn, G., Schirrmeister, L., and Diekmann, B.: Onset of intense permafrost conditions in Northern Eurasia at ~2.55 Ma seen in a cryogenic weathering record from Lake El'gygytgyn, Clim. Past Discuss., 9, 6255-6285, https://doi.org/10.5194/cpd-9-6255-2013, 2013.
G. Schwamborn et al.
G. Schwamborn et al.

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