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Titel |
Content and distribution of trace metals in pristine permafrost environments of Northeastern Siberia, Russia |
VerfasserIn |
I. Antcibor, A. Eschenbach, L. Kutzbach, D. Bolshiyanov, E.-M. Pfeiffer |
Konferenz |
EGU General Assembly 2012
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Medientyp |
Artikel
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Sprache |
Englisch
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 14 (2012) |
Datensatznummer |
250066678
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Zusammenfassung |
Arctic regions are one of the most sensitive areas with respect to climatic changes and human
impacts. Research is required to discover how the function of permafrost soils as a
buffering system for metal pollutants could change in response to the predicted
changes.
The goal of this work is to determine the background levels of trace metals in the pristine
arctic ecosystems of the Lena River Delta in Northeastern Siberia and to evaluate the possible
effect of human impacts on this arctic region. The Lena River Delta represents areas with
different dominating geomorphologic processes that can generally be divided between
accumulation and erosion sites. Frequent changes of the river water level create different
periods of sedimentation and result in the formation of stratified soils and sediment layers
which are dominated either by mineral substrates with allochthonous organic matter
or pure autochthonous peat. The deposited sediments that have formed the delta
islands are mostly composed of sand fractions; therefore the buffering effects of clay
materials can be neglected. Samoylov Island is representative of the south-central and
eastern modern delta surfaces of the Lena River Delta and is selected as a pilot study
site.
We determined total element contents of Fe, Mn, Zn, Cd, Ni, Cu, As, Pb, Co and Hg in
soil horizons from different polygonal elevated rims, polygonal depressed centers and the
middle floodplain. High gravimetric concentrations (related to dry mass of soil material) of
Mn and Fe are found within all soil profiles and vary from 0.14 to 1.39 g kg-1 and from 10.7
to 41.2 g kg-1, respectively. While the trace element concentrations do not exceed
typical crustal abundances, the maximum values of most of the metals are observed
within the soil profile situated at the middle floodplain. This finding suggests that
apart from the parent material the second potential source of trace metals is due to
allochthonous substance input during annual flooding of the middle floodplain. Correlation
analysis between element concentrations, grain-size distribution and carbon content
revealed a direct dependence of the element distribution within all soil profiles on its
mineralogical composition. Based on the obtained results we suggest that there are
negligible atmospheric depositions caused by human activity on the investigation site.
Therefore this data can provide a point of comparison against man-made influences on
permafrost-affected landscapes and also on similar pristine areas in the Arctic region. |
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