| 黄土高原南部全新世黄土-古土壤 序列若干元素分布特征及意义* |
| |
| 引用本文： | 庞奖励,黄春长,刘安娜,王利军.黄土高原南部全新世黄土-古土壤 序列若干元素分布特征及意义*[J].第四纪研究,2007,27(3):357-364. |
| |
| 作者姓名： | 庞奖励 黄春长 刘安娜 王利军 |
| |
| 作者单位： | 1. 陕西师范大学旅游与环境学院/西北历史环境与经济社会发展研究中心,西安,710062;中国科学院地球环境研究所黄土与第四纪地质国家重点实验室,西安,710075
2. 陕西师范大学旅游与环境学院/西北历史环境与经济社会发展研究中心,西安,710062 |
| |
| 基金项目： | 国家自然科学基金
,
国家重点实验室基金
,
陕西师范大学校科研和教改项目 |
| |
| 摘 要： | 选择黄土高原南部的XJN,XMC和JYC全新世剖面为研究对象。通过对地层中Ca,Ba,Rb和Sr元素分布的研究,发现Ba/Sr和Rb/Sr比值在不同地层中含量差异十分明显,并与成土作用强度显著正相关,可作为良好的气候替代指标;表生环境中Rb和Ba较稳定,Sr和Ca元素十分活跃,易于迁移,其中Ca的迁移能力高于Sr元素;从XJN→XMC→JYC剖面,Rb和Ba元素含量增加,而Sr和Ca元素含量降低,这与区域环境差异有关;全新世中期暖湿的亚热带气候主要出现关中盆地地区,六盘山以西则是暖温带气候。
|
| 关 键 词： | Ba/Sr和Rb/Sr比值 黄土-古土壤序列 全新世 |
| 文章编号： | 1001-7410（2007）03-357-08 |
| 收稿时间： | 2006-08-03 |
| 修稿时间： | 2006-12-22 |
Ba/Sr AND Rb/Sr RATIO OF HOLOCENE LOESS-PALAEOSOL SEQUENCES AND ITS SIGNIFICANCE IN SOUTH LOESS PLATEAU, CHINA |
| |
| Pang Jiangli,Huang Chunchang,Liu An'na,Wang Lijun.Ba/Sr AND Rb/Sr RATIO OF HOLOCENE LOESS-PALAEOSOL SEQUENCES AND ITS SIGNIFICANCE IN SOUTH LOESS PLATEAU, CHINA[J].Quaternary Sciences,2007,27(3):357-364. |
| |
| Authors: | Pang Jiangli Huang Chunchang Liu An'na Wang Lijun |
| |
| Institution: | College of Tourism and Environmental Sciences/Northwest Research Center for Historical Environment and Socio-economic Development, Shaanxi Normal University, Xi'an710062|State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an710075 |
| |
| Abstract: | The Holocene loess-soil sequences are of great values in the study of paleoclimate. Loess and soil samples from three Holocene sites at Xujianan(XJN), Xiamengcun(XMC), and Jiangyangcun(JYC) in the southern Loess Plateau were analyzed for their Ca, Ba, Rb, and Sr concentrations. Experimental results show that Ca, Ba, Rb, and Sr element concentrations and Ba/Sr and Rb/Sr ratios have obvious differentiation in palaeosol and loess layers, and an obvious differentiation of geochemical properties of the XJN, XMC, and JYC sites has been recognized. The Ba/Sr and Rb/Sr ratios of soil S0 gradually increase when soil type varies from the Eluvial Cinnamon soil of the JYC site to the Heilutu soil of the XJN site. These results indicate that the Ba/Sr and Rb/Sr ratios are very sensitive to climatic change and are thus good proxy indexes of climatic change during the Holocene. High value of Ba/Sr and Rb/Sr ratios indicates strong weathering, high precipitation and strong life activity, while low value indicates decreased weathering intensity, lower precipitation and increasing accumulation of aeolian dust. In comparison with Sr and Ca elements, under hypergene environments Rb and Ba elements are relatively stable and thus remain in palaeosol layers, while Sr and Ca are more active and easily leached out from palaeosol layers. Our results suggest that migration ability of Ca is higher than that of Sr. Statistic analyses suggest that there is a close relation between Ca, Ba, Rb, Sr element concentrations and grain size. The Ba and Rb elements tend to distribute in particle of less than 25μm in diameter, while the Ca and Sr elements tend to distribute in particle of more than 25μm in diameter. Research results show that there exists an obvious positive correlation between Ba and Rb element contents and particle of less than 10μm in diameter, and an obvious positive correlation between Ca and Sr element contents and particle between 10~50μm. The XJN site displays some differences from the XMC and JYC sites. From the XJN site to the XMC and JYC sites, Rb element content varies from 100.3mg/kg to 103.1mg/kg and 111.8mg/kg; Ba content varies from 495.3mg/kg to 500.8mg/kg and 525.9mg/kg, Sr content varies from 235.1mg/kg to 164.9mg/kg and 148.2mg/kg, while Ca content varies from 70.2g/kg to 44.7g/kg and 35.5g/kg. These are attributable to regional environment difference. All results of this research suggest that during the Holocene Megathermal the climate in the Guanzhong areas was wet-warm subtropical, which was characterized by forming Eluvial Cinnamon soil, and that in the western Liupan Mountains was warm temperate, which was characterized by forming Heilutu soil. Ba/Sr and Rb/Sr ratios of Holocence loesss-paleosol record the evolutionary history of the East Asian monsoonal system. |
| |
| Keywords: | Ba/Sr and Rb/Sr ratio Holocene South Loess Plateau |
| 本文献已被 CNKI 维普 万方数据 等数据库收录！ |
| 点击此处可从《第四纪研究》浏览原始摘要信息 |
| 点击此处可从《第四纪研究》下载免费的PDF全文 |
|
