艾比湖滨岸盐碱土中碳酸盐的XRD衍射特征与微观形态分析

发布时间：2019-01-02 19:48

【摘要】：结合X射线衍射(XRD)、扫描电镜(SEM)和能谱分析(EDS)方法,对现代盐湖沉积环境下,新疆艾比湖滨岸盐碱土中碳酸盐的分布特征、存在形式以及与其他土壤原生、次生矿物之间的关系进行探讨,结果表明:艾比湖滨岸盐碱土中的原生矿物主要是石英和长石,粘土矿物主要为绿泥石和伊利石,土壤矿物的风化程度顺序为北部西部东部,西部样点的现代盐湖化学沉积作用最为显著,北部样点则生物风化过程十分强烈;XRD方法和气量法分别测得的碳酸盐含量之间呈极显著正相关关系,判定系数R~2达0.640 9。当盐碱土中含有较高的绿泥石时,碳汇潜力会增加,同时,XRD方法对碳酸盐相对含量的鉴定误差也明显增加,衍射峰形变得复杂,碳酸盐含量明显被低估,低估原因可能与有机质含量高导致的弥散散射增加及粘土矿物含量高使得类质同象现象增加有关;西部和北部土壤矿物溶蚀强烈,石膏以纤维状或长柱状晶体分散或放射状分布于方解石晶体之间,方解石则以异质成核形式呈颗粒状或片状在其他矿物或底质表面生长,表现为次生碳酸盐形貌特征。
[Abstract]:Combined with X-ray diffraction (XRD),) scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) analysis, the distribution characteristics, forms of carbonate distribution in saline and alkali soils along the shore of Abi Lake, Xinjiang, and their primary characteristics with other soils were studied. The results show that the primary minerals are mainly quartz and feldspar, the clay minerals are mainly chlorite and Illite, and the weathering degree of soil minerals is in the order of the northern west and the east. The chemical deposition of the modern salt lake in the western sample is the most obvious, and the biological weathering process in the northern sample is very strong. There was a significant positive correlation between the carbonate content measured by the XRD method and the gas volume method, and the coefficient of determination was 0.640 9. The potential of carbon sequestration will increase when the salt alkali soil contains high chlorite. At the same time, the identification error of XRD method for the relative content of carbonate also increases obviously, the diffraction peak form becomes complex, and the carbonate content is obviously underestimated. The reason of underestimation may be related to the increase of dispersion scattering caused by the high content of organic matter and the increase of isomorphism caused by the high content of clay minerals. Soil minerals in the western and northern parts of the country are strongly eroded, gypsum is dispersed or radially distributed between calcite crystals in the form of fibrous or long columnar crystals, and calcite grows on the surface of other minerals or substrates in the form of heterogeneous nucleation. It is characterized by the morphology of secondary carbonate.
【作者单位】：新疆大学资源与环境科学学院;新疆大学生态学博士后流动站;教育部新疆绿洲生态重点实验室;
【基金】：国家自然科学基金项目(41261049,41130531) 中国博士后基金面上项目(2013M532100)资助
【分类号】：S153.6

【相似文献】