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Titel |
Stable isotope and gas properties of two climatically contrasting (Pleistocene and Holocene) ice wedges from Cape Mamontov Klyk, Laptev Sea, northern Siberia |
VerfasserIn |
T. Boereboom, D. Samyn, H. Meyer, J.-L. Tison |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1994-0416
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Digitales Dokument |
URL |
Erschienen |
In: The Cryosphere ; 7, no. 1 ; Nr. 7, no. 1 (2013-01-04), S.31-46 |
Datensatznummer |
250004443
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Publikation (Nr.) |
copernicus.org/tc-7-31-2013.pdf |
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Zusammenfassung |
This paper presents and discusses the texture, fabric, water stable isotopes
(δ18O, δD) and gas properties (total gas content,
O2, N2, Ar, CO2, and CH4 mixing ratios) of two
climatically contrasted (Holocene vs. Pleistocene) ice wedges (IW-26 and
IW-28) from Cape Mamontov Klyk, Laptev Sea, in northern Siberia. The two ice
wedges display contrasting structures: one being of relatively "clean" ice
and the other showing clean ice at its centre as well as debris-rich ice on
both sides (referred to as "ice-sand wedge"). Our multiparametric approach
allows discrimination between three different ice facies with specific
signatures, suggesting different climatic and environmental conditions of
formation and various intensities and nature of biological activity. More
specifically, crystallography, total gas content and gas composition reveal
variable levels of meltwater infiltration and contrasting contributions from
anaerobic and aerobic conditions to the biological signatures. Stable
isotope data are drawn on to discuss changes in paleoenvironmental
conditions and in the temporal variation of the different moisture sources
for the snow feeding into the ice wedges infillings. Our data set also
supports the previous assumption that the ice wedge IW-28 was formed in
Pleistocene and the ice wedge IW-26 in Holocene times. This study sheds more
light on the conditions of ice wedge growth under changing environmental
conditions. |
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