Pedosphere 15(4): 539--544, 2005
ISSN 1002-0160/CN 32-1315/P
©2005 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Stable carbon and oxygen isotopes of pedogenic carbonates in Ustic Vertisols: Implications for paleoenvironmental change |
HUANG Cheng-Min1,2 , WANG Cheng-Shan2 and TANG Ya1 |
1 Department of Environmental Science and Technology, Sichuan University, Chengdu 610065 (China). E-mail: cmhuang@tom.com
2 Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu 610059 (China) |
| ABSTRACT |
| Pedogenic carbonates, found extensively in arid and semiarid regions, are important in revealing regional climatic and environmental changes as well as the carbon cycle. In addition, stable carbon and oxygen isotopic compositions of pedogenic carbonates have been used to rebuild paleoecology (biomass and vegetation) and to estimate paleotemperature and paleoprecipitation during past geological time. By utilizing the stable carbon and oxygen isotopic compositions (δ13C) and (δ18O) of secondary nodules in Ustic Vertisols, this study looked into the climatic and environmental changes in the dry valleys of the Yuanmou Basin, Yunnan Province, in southwestern China. The results showed that during the early Holocene, a warm-humid or hot-humid climate existed in the Yuanmou Basin, but since then fluctuations in climate have occurred, with a dry climate prevailing. A highly significant correlation (r = 0.92, n = 9) between δ13C and δ18O values of carbonates illustrated that there had been a continual shifting between cold-humid and warm-dry climates in southwestern China including the Yuanmou Basin since the early Holocene. |
| Key Words: carbon, isotopic composition, oxygen, pedogenic carbonates, Ustic Vertisols |
| Citation: Huang, C. M., Wang, C. S. and Tang, Y. 2005. Stable carbon and oxygen isotopes of pedogenic carbonates in Ustic Vertisols: Implications for paleoenvironmental change. Pedosphere. 15(4): 539-544. |
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