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| Titel |
A record of Quaternary humidity fluctuations on the NE Tibetan Plateau based on magnetic susceptibility variations in lacustrine sediments of the Qaidam Basin |
| VerfasserIn |
Christian Herb, Andreas Koutsodendris, Weilin Zhang, Erwin Appel, Jörg Pross, Xiaomin Fang |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250075943
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| Zusammenfassung |
| Magnetic susceptibility (Ï) and other magnetic proxies play an important role in
paleoclimatic studies as they hold the potential for high-resolution records of past
environmental change. Nevertheless, it is necessary to understand the cause of the variation
in magnetic proxies by comparing them to more direct climate proxies such as
pollen or stable isotopes. In this study we have compiled a high-resolution magnetic
proxy dataset of the ca. 940-m-long core SG-1, which was drilled in the lacustrine
sediments of the western Qaidam Basin on the northeastern Tibetan Plateau. Our record
spans the entire Quaternary (~2.8 to 0.1 Ma). The magnetic susceptibility record is
compared to the Artemisia/Chenopodiaceae (A/C) ratio, which is used to discriminate
between dry and more humid phases in the Qaidam Basin, based on (i) 41 samples
spanning the Middle Pleistocene Transition (MPT; ~1 Ma BP) and (ii) additional 40
samples selected from intervals of minimum and maximum Ï values throughout the
core. For the drill core SG-1, we observe a high correlation of the A/C ratio with Ï
results: minima of Ï correspond to maxima of the A/C ratio (representing more
humid phases) and vice versa. Additionally, spectral analysis of the Ï record shows
the emergence of the 100-ka Milankovitch cycle after the MPT. This testifies to
the fact that cyclic variation of Ï represents a response to global climate change. |
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