Applying distribution characteristics of chemical elements during soil-forming process to resume palaeo-environmental evolution is a key field in the research of past global changes. This paper divided the continuous strata of the Zhongba site in Chongqing into 12 sub-layers according to cultural sequence over last 5 ka, measuring Rb, Sr, Cr and Cu contents respectively by XRF and ICP-AES methods. Results indicated that Cr has similar chemical nature as Rb with low activity and is apt to deposit in fine sand materials. Meanwhile, Cu and Sr are easy to be transported over the weathering process and enrich in claypan. A linear regression demonstrated that Cr/Cu ratios are positively relative to Rb/Sr ratios. After comparing variation curves of Cr/Cu ratios with climatic records of peat humification in Hongyuan, northeast region of the Tibet Plateau in last 5 ka, they both are well consistent with each other. Therefore, this paper suggested that Cr/Cu ratios as Rb/Sr be a reliable proxy to indicate palaeo-environment even with higher accuratcy. Obviously, Cr/Cu ratios will be significant in geo-archaeological research.
LI Zhong-xuan, ZHU Cheng, ZHU Qing, MA Chun-mei, ZHANG Guang-sheng, OUYANG Jie
. Variation of Cr/Cu Ratios in Zhongba Profile and Its Indication on Palaeo-environment over Last 5 ka[J]. SCIENTIA GEOGRAPHICA SINICA, 2008
, 28(6)
: 799
-803
.
DOI: 10.13249/j.cnki.sgs.2008.06.799
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