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| Titel |
Excursions to C4 vegetation recorded in the Upper Pleistocene loess of Surduk (Northern Serbia): an organic isotope geochemistry study |
| VerfasserIn |
C. Hatté, C. Gauthier, D.-D. Rousseau, P. Antoine, M. Fuchs, F. Lagroix, S. B. Marković, O. Moine, A. Sima |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 9, no. 3 ; Nr. 9, no. 3 (2013-05-03), S.1001-1014 |
| Datensatznummer |
250018050
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| Publikation (Nr.) |
 copernicus.org/cp-9-1001-2013.pdf |
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| Zusammenfassung |
| Loess sequences have been intensively studied to characterize past glacial
climates of the 40–50° north and south latitude zones. Combining
different approaches of sedimentology, magnetism, geochemistry,
geochronology and malacology allows the general pattern of the climate and
environment of the last interglacial–glacial cycle in Eurasia and America to
be characterized. Previous studies performed in Europe have highlighted the
predominance (if not the sole occurrence) of C3 vegetation. The
presence of C3 plants suggests a regular distribution of
precipitation along the year. Therefore, even if the mean annual
precipitation remained very low during the most extensive glacial times,
free water was available for more than 2 months per year. Contrarily, the
δ13C record of Surduk (Serbia) clearly shows the occurrence and
dominance of C4 plants during at least 4 episodes of the last glacial
times at 28.0–26.0 kyr cal BP, 31.4–30.0 kyr cal BP, 53.4–44.5 kyr cal BP
and 86.8–66.1 kyr. The C4 plant development is interpreted as a specific
atmospheric circulation pattern that induces short and dry summer
conditions. As possible explanation, we propose that during "C4
episodes", the Mediterranean Sea would have been under the combined
influence of the following: (i) a strong meridional circulation unfavorable
to water evaporation that reduced the Mediterranean precipitation on the
Balkans; and (ii) a high positive North Atlantic Western Russian (NA/WR)-like
atmospheric pattern that favored northerlies over westerlies and reduced
Atlantic precipitation over the Balkans. This configuration would imply very
dry summers that did not allow C3 plants to grow, thus supporting
C4 development. The intra-"C4 episode" periods would have occurred
under less drastic oceanic and atmospheric patterns that made the influence
of westerlies on the Balkans possible. |
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