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| Titel |
Carbonate sedimentation and effects of eutrophication observed at the Kališta subaquatic springs in Lake Ohrid (Macedonia) |
| VerfasserIn |
M. Matter, F. S. Anselmetti, B. Jordanoska, B. Wagner, M. Wessels, A. Wüest |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 7, no. 11 ; Nr. 7, no. 11 (2010-11-23), S.3755-3767 |
| Datensatznummer |
250005068
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| Publikation (Nr.) |
 copernicus.org/bg-7-3755-2010.pdf |
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| Zusammenfassung |
| To date, little is known about the role of spring waters with respect to
authigenic carbonate precipitation in a shallow lacustrine setting. Lake
Ohrid, located in Southeastern Europe, is a large lake fed to over 50%
by karstic springs of which half enter subaquatically and influence
significantly its ecology and species distribution. In order to evaluate how
sedimentological processes are influenced by such shallow-water springs, the
Kališta subaquatic spring area in the north west of Lake Ohrid was
investigated by a sidescan sonar survey and with sediment traps and three
transects of gravity short cores. Results indicate that sedimentation in the
spring area is dominated by authigenic carbonate precipitation. High
sedimentation rates and evidences for bio-induced precipitation processes
were observed in the water column and in the sediments. Two distinct
stratigraphic units characterize the shallow subsurface, both composed of
carbonate silts with high carbonate contents of up to 96%, but differing
in color, carbonate content and diatom content. A chronological correlation
of the cores by radiocarbon dates and 137Cs activities places the
transition between the two stratigraphic units after ~1955 AD. At that
time, coastal sedimentation changed drastically to significantly darker
sediments with higher contents of organic matter and more abundant diatoms.
This change coincides with the recent human impact of littoral
eutrophication. |
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