Geochemistry of Rare Earth Elements and Origin of Positive Europium Anomaly in MioceneOligocene Lacustrine Carbonates from Tuotuohe Basin of Tibetan Plateau
- Received Date: 1900-01-01
- Rev Recd Date: 1900-01-01
- Publish Date: 2008-02-10
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Key words:
- rare earth element /
- positive europium anomaly /
- hydrothermal activity /
- lacusrine carbonate /
- Cenozoic /
- Tibetan Plateau
Abstract: The concentrations of rare earth elements(REE) and trace elements were analysed from MioceneOligocene lacustrine carbonates collected in the Tongtianhe section of Tuotuohe Basin of Tibetan Plateau. The total REE contents(∑REE) of lacustrine limestone and dolostones covers a wide range:36.23×10-6～189.64×10-6 and its average value of 28 samples is 78.58×10-6. The shalenormalized REE patterns display middle REE enrichments and strong positive Eu anomalies. The relatively high Eu/Eu* ratios occur across the Oligocene and Miocene boundary layers. This is the first report of positive Eu anomalies observed in REE patterns in terrestrial sediment records. Based on REE distributions and covariance between Eu and Ba, this paper presents Eu anomaly in lacustrine carbonate samples of the study area implies hydrothermal venting occurrence in paleolake systems.
| Citation: | YI Haisheng. Geochemistry of Rare Earth Elements and Origin of Positive Europium Anomaly in MioceneOligocene Lacustrine Carbonates from Tuotuohe Basin of Tibetan Plateau[J]. Acta Sedimentologica Sinica, 2008, 26(1): 1-10.
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