Clay record of climate change since the mid-Pleistocene in Jiujiang, south China
Version of Record online: 5 OCT 2012
© 2012 The Authors. Boreas © 2012 The Boreas Collegium
Volume 42, Issue 1, pages 173–183, January 2013
How to Cite
2012: Clay record of climate change since the mid-Pleistocene in Jiujiang, south China. Boreas, 10.1111/j.1502-3885.2012.00276.x. ISSN 0300-9483., , , & .
- Issue online: 21 DEC 2012
- Version of Record online: 5 OCT 2012
- Manuscript Accepted: 13 JUN 2012
- Manuscript Received: 2 SEP 2011
- Natural Science Foundation of China. Grant Numbers: 41072030, 40872038
- the Specialized Research Fund for the Doctoral Program of Higher Education of China. Grant Number: 20110145110001
To obtain a better understanding of climate change in south China in the Quaternary, a clay mineralogical study was undertaken on the red earth profile at Jiujiang, using X-ray diffraction (XRD) and particle-size distribution analysis methods. The XRD results showed that the clay minerals of the Jiujiang red earth were mainly mixed-layer illite–smectite (I/S), illite, kaolinite and vermiculite, with trace amounts of mixed-layer kaolinite–smectite (K/S). Changes in clay mineral composition displayed a trend of three-stage evolution. The higher mixed-layer I/S clays and kaolinite contents in the lower portion suggest extremely warm and humid climates over the period c. 700 to c. 350 ka ago. A gradual decrease in I/S clays and kaolinite reveals a gradual climate change from warm/humid to cool/dry during the period c. 350 to c. 130 ka ago. The higher illite and vermiculite contents indicate a relatively cool and dry climate during the period since c. 130 ka ago. The particle-size distribution pattern of the upper section was similar to that of the Xiashu loess, while that of the middle to lower section was similar to those of fluvially reworked red earth. A rapid increase in the abundance of large grain-size components at 2.6 m depth indicates an intensification of the winter monsoon and a cool and dry climate during the period, in good agreement with results from the clay mineral composition and homogeneous structure. The red earth sequences in south China could probably be used to test the response of tropical to subtropical regions to global climate changes.