Sedimenttransport durch das arktische Meereis: die rezente lithogene und biogene Materialfracht
Sediments extracted from surface samples and ice cores of sea ice from the Eurasian Basin, Fram Strait, Greenland and Barents Sea have been investigated for detailed sedimentological analyses. Analyses comprise sand/silt/clay distribution, coarse fraction analyses, grain size distribution of the sil...
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| Format: | Thesis |
| Language: | German |
| Published: |
1991
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| Online Access: | https://oceanrep.geomar.de/id/eprint/43632/ https://oceanrep.geomar.de/id/eprint/43632/1/Wollenburg.pdf |
| Summary: | Sediments extracted from surface samples and ice cores of sea ice from the Eurasian Basin, Fram Strait, Greenland and Barents Sea have been investigated for detailed sedimentological analyses. Analyses comprise sand/silt/clay distribution, coarse fraction analyses, grain size distribution of the silt fraction, clay mineralogy, measurements of carbonate, sulfur and organic carbon contents and the geochemistry of trace elements. In situ-observations of the particulate loads in Arctic Ocean sea ice during investigations carried out in 1987-1990 show the importance of sea ice rafting for the modern Arctic sedimentary environment. Sediments composed of lithogenic and biogenic material were observed in concentrations and areal extents high enough to account for a large portion of the average sedimentation rate in potential ablation areas (e.g. Fram Strait). For the first time ever, differences in clay mineralogy with signifivant high smectite values make back-tracing to a distinct source region which is the Laptev Sea possible. With the sedimentological data, variations in ice drift can be specified and allow an interpretation of patterns in sea floor sediments to be made. The biogenic components confirm the origin in shallow water areas and are part of a special 'cryopelagic fauna', which is characteristic for the sea ice environment. From the results of grain size analyses, a similar and uniform incorporation by resuspension of sea florr sediments for most of the sea ice sediments can be concluded. This information may be a tool for identifying sea ice covers and sediment transport in the sedimentary record of the past. |
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