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| Titel |
Terrestrial mollusc records from Xifeng and Luochuan L9 loess strata and their implications for paleoclimatic evolution in the Chinese Loess Plateau during marine Oxygen Isotope Stages 24-22 |
| VerfasserIn |
B. Wu, N. Q. Wu |
| 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 ; 7, no. 2 ; Nr. 7, no. 2 (2011-04-20), S.349-359 |
| Datensatznummer |
250004504
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| Publikation (Nr.) |
 copernicus.org/cp-7-349-2011.pdf |
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| Zusammenfassung |
| Marine Isotope Stages 24-22 is a key period of the Mid-Pleistocene
Transition, however, its climate variability is still unclear. The
coarse-grained loess unit L9, one of the most prominent units in the Chinese
loess stratigraphy, yields a high potential terrestrial record of
paleoclimatic and paleoenvironmental changes during this period. In this
study, two high-resolution terrestrial mollusc records of L9 loess strata
from the Xifeng and Luochuan sequences in the Chinese Loess Plateau were
analysed. Our mollusc results show that the MIS 24, the early and late parts
of MIS 22 were dominated by cold and dry climate. Relatively mild-humid
climate occurred in MIS 23 and the middle part of MIS 22. The climatic
conditions at Xifeng region were cooler and more unstable compared to
Luochuan region. A comparison of mollusc species composition and other
proxies of L9 strata (MIS 24-22) with those of L1 loess units (MIS 4-2)
indicates that the L9 loess was not deposited under the most severe glacial
conditions in Quaternary climate history as suggested in previous studies.
Our study shows that climatic conditions in the Loess Plateau during the L9
loess forming period were similar to that of gentle glacials (MIS 24 and MIS
22) and interglacial (MIS 23), as suggested by the marine δ18O
record. Three cooling fluctuations occurred at ~930 ka, 900 ka and
880 ka, which might hint to the global "900 ka cooling event". The
"900-ka event" in the Loess Plateau does not seem to be a simple long
glaciation, but rather several complex climatic fluctuations superposed
on a general cooling trend. The uplift of the Tibetan Plateau and the general
cooling experienced by the Earth during this period may have resulted in
abundant dust sources and increased dust transport capability, as indicated
by increased grain size and the mass accumulation rate of L9 loess. |
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