###
DOI:
地质力学学报:2013,19(1):26-34
本文二维码信息
码上扫一扫!
成都平原风尘堆积的化学风化特征及其古气候意义
(1.中国地质科学院地质力学研究所, 北京 100081;2.国土资源部新构造运动与地质灾害重点实验室, 北京 100081)
CHEMICAL WEATHERING CHARACTERISTICS AND PALEOCLIMATIC SIGNIFICANCE OF THE EOLIAN DEPOSITS IN CHENGDU PLAIN
(1.Institute of Geomechanics, CAGS, Beijing 100081, China;2.Key Laboratory of Neotectonic Movement and Geohazard, Beijing 100081, China)
摘要
图/表
参考文献
相似文献
本文已被:浏览 1606次   下载 1351
投稿时间:2012-10-15    
中文摘要: 对成都平原胜利红土剖面进行了系统的常量元素分析,并与川西典型黄土、古土壤样品的地球化学特征进行对比,研究本区风尘堆积所经历的化学风化作用过程,并对该序列化学风化特征的古气候意义进行探讨。研究结果表明,成都红土的常量元素组成与川西典型黄土、古土壤样品相似,与上地壳的平均化学成分也基本一致,说明成都红土与川西黄土一样,在堆积以前也经历了多次充分混合作用。在成都红土的形成过程中,Ca、Na元素大量淋失,含量很低,K、Mg也出现了不同程度的淋失,说明成都红土经历了斜长石和钾长石的化学风化过程。进一步的研究表明,成都黏土已达到中等风化的末期阶段,而网纹红土已进入强烈风化作用阶段。从整个序列的化学风化参数来看,距今1.13 Ma以来化学风化强度不断减弱,表明四川盆地及周围地区更新世中期以来有逐渐变干的趋势,与全球气候变化具有一致性。
中文关键词: 成都红土  风尘堆积  化学风化  古气候
Abstract:The chemical composition of the eolian deposits mainly depends on the material composition of the source area and post-depositional in-situ pedogenesis. In this study, systematic major element composition analysis has been made Shengli red earth section in Chengdu Plain, and compared with the geochemical characteristics of typical loess and paleosoil samples from western Sichuan Province. The research results show that, similar major element composition between the Chengdu Red Earth and the loess-paleosoil samples from western Sichuan, and they are also comparable to the average composition of the Upper Continental Crust. These suggest that the Chengdu Red Earth, as same as loess from western Sichuan, were all derived from well-mixed sedimentary protoliths which had undergone numerous upper crustal recycling processes. In the formation process of the Chengdu Red Earth, Ca and Na element experienced a large number of leaching and the content is very low, K and Mg also appeared different degree of leaching, explaining Chengdu Red Earth experienced chemical weathering process of plagioclase and potassium feldspar. Further study shows that, Chengdu clay has reached the later stage of medium degree of chemical weathering, and the vermiculated red soil has entered the strong weathering stage. From the chemical weathering parameters of the entire sequence, weakening chemical weathering intensity from 1.13 MaBP shows that Sichuan Basin and the surrounding area has gradually become drier since the mid-pleistocene, and has consistency with global climate change.
文章编号:     中图分类号:    文献标志码:
基金项目:中国地质调查局地质矿产调查评价专项(1212011087118);国土资源部公益性行业科研专项(201211077)
引用文本:
谭元隆,乔彦松,赵志中,等,2013.成都平原风尘堆积的化学风化特征及其古气候意义[J].地质力学学报,19(1):26-34.DOI:
TAN Yuan-long,QIAO Yan-song,ZHAO Zhi-zhong,et al,2013.CHEMICAL WEATHERING CHARACTERISTICS AND PALEOCLIMATIC SIGNIFICANCE OF THE EOLIAN DEPOSITS IN CHENGDU PLAIN[J].Journal of Geomechanics,19(1):26-34.DOI:

用微信扫一扫

用微信扫一扫