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篇目详细内容 |
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【篇名】 |
n-alkanol ratios as proxies of paleovegetation and paleoclimate in a peat-lacustrine core in southern China since the last deglaciation |
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【刊名】 |
Frontiers of Earth Science in China |
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【刊名缩写】 |
Front. Earth Sci. China |
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【ISSN】 |
1673-7385 |
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【EISSN】 |
1673-7490 |
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【DOI】 |
10.1007/s11707-009-0052-2 |
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【出版社】 |
Higher Education Press and Springer-Verlag |
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【出版年】 |
2009 |
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【卷期】 |
3
卷4期 |
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【页码】 |
445-451
页,共
7
页 |
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【作者】 |
Yanhong ZHENG;
Shucheng XIE;
Xiaomin LIU;
Weijian ZHOU;
Philip A. MEYERS;
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【关键词】 |
southern China; n-alkanols; lipids; paleovegetation and paleoclimate; geobiology |
【摘要】 |
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High resolution records of long chain n-alkanol biomarkers were obtained from a peat-lacustrine core from the Dingnan profile in southern China. The n-alkanol distributions are characterized by the predominance of even-over-odd carbon number and maximize at C24 or C26. On the basis of the reported n-alkanol records in the literature and the n-alkane record in our samples, we concluded that the n-alkanol ratio of C26/C30 varying from 1.25 to 6.48, together with the n-alkanol ratio C22/C24 less than unity, is indicative of the presence of a dominant forest paleovegetation. A 2000-year cycling in the variation of the n-alkanol ratio C26/C30 is identifiable in our profile, and probably results from the change in the abundance of the grass relative to trees induced by a cyclic paleoclimate. The n-alkanol ratio C24/C26 appears to be more sensitive to change in precipitation than in temperature, and may be a potential indicator of precipitation/humidity, with increased values being associated with relatively dry conditions. The paleovegetation and the paleoclimate reconstructed on the basis of the n-alkanol records for the recent 18000 cal a BP in general accord with the pollen data and other lipid evidence recorded in the Dingnan region in southern China. In particular, both the n-alkanol records and the pollen data infer the different paleoclimate conditions for the two peat sequences, with a cool and wet climate dominating in the lower peat deposition formed during the latest Pleistocene and a change to a drier and cooler climate occurring in the upper peat sequence in mid-Holocene. |
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