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| Titel |
Mineral magnetic study of lacustrine sediments from Pumoyum Co Lake, southern Tibet, over the last 19 ka and paleoenvironmental significance |
| VerfasserIn |
Youliang Su, Xing Gao, Qingsong Liu, Junbo Wang, Jinhua Li, Zongqi Duan |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250047481
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| Zusammenfassung |
| The Tibetan Plateau plays an important role in controlling Northern Hemisphere atmospheric
circulation and affects global climate. Therefore, high-resolution paleoclimatic records from
this region are essential for understanding the coupling between local and global climate. We
conducted systematic environmental magnetic studies on lacustrine sediments that date
since the last deglaciation (~19 ka) from Pumoyum Co Lake, southern Tibet. From
paleoenvironmental and magnetic property data, the studied sequence can be divided into
three major units. Unit 1 spans the Holocene when the environment was oxic, in
which an upward increasing trend is observed in the concentration of magnetic
minerals. This trend can be interpreted as an increasing transportation of magnetic
minerals from the catchment into the lake due to increased post-glacial melt-water
flow. In contrast, both units 2 and 3 contain evidence of reducing environment.
Fine-grained greigite dominates the bulk magnetic properties of unit 3, while both
magnetite and greigite coexist in unit 2. The enhanced magnetic signal in unit 2 is
mainly due to the increased precipitation which results in more detrital magnetic
mineral rushed into the lake. Our results suggest that the climate of southern Tibet is
teleconnected to high-latitude Northern Hemisphere climate variations. Although
different mechanisms dominate the magnetic assemblage and associated magnetic
properties in different units, environmental magnetic studies have considerable
potential to provide important insights into paleoclimate variations in this region. |
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