...
首页> 外文期刊>Applied clay science >Maghemite quantification and magnetic signature of Brazilian soils with contrasting parent materials
【24h】

Maghemite quantification and magnetic signature of Brazilian soils with contrasting parent materials

机译:对比母质的巴西土壤的磁赤铁矿定量和磁特征

获取原文
获取原文并翻译 | 示例
   

获取外文期刊封面封底 >>

       

摘要

Maghemite (Mh) is a ferrimagnetic mineral that governs magnetism in the clay fraction, especially in well weathered soils from tropical and subtropical regions. In this work, we assessed different methods for Mh quantification [1: area of the reflections obtained by X-ray diffraction (XRD) (standard method); 2: Rietveld refinement; 3: selective dissolution with H2SO4 and; 4: magnetic susceptibility (chi)) by application to Brazilian soils with contrasting parent materials (itabirite, basalt, gabbro, tuffite, gneiss and amphibolite). The methods based on H2SO4 dissolution were found to overestimate the Mh content with respect to the standard method based on X-ray diffraction. This was particularly so with samples from gneiss and amphibolite and samples with higher contents in poorly crystalline Fe oxides. Mh contents based on magnetic susceptibility measurements or the XRD-Rietveld refinement were closer to those provided by the standard method. Mh was found to accumulate in well weathered soils and soils with a high Fe2O3 content. Exception were soils from tuffite, which had high Fe2O3 contents (similar to 330 g kg(-1)), exhibited low Mh levels (similar to 5.5 g kg(-1)). Irrespective of the parent material, Mh particles typically fall in a single domain magnetic behavior; however, they can also acquire multidomain characteristics, probably as a result of isomorphic substitution and aggregation with hematite.
机译:磁赤铁矿(Mh)是一种亚铁磁性矿物,控制粘土部分中的磁性,尤其是来自热带和亚热带地区的风化土壤。在这项工作中,我们评估了不同的Mh量化方法[1:通过X射线衍射(XRD)获得的反射面积(标准方法); 2:Rietveld精致; 3:用H 2 SO 4和选择性溶解; 4:磁化率(chi),通过在母本上形成对比的母料(异铁矿,玄武岩,辉长岩,凝灰岩,片麻岩和角闪石)施用于巴西土壤。与基于X射线衍射的标准方法相比,发现基于H2SO4溶解的方法高估了Mh含量。来自片麻岩和角闪石的样品,以及结晶度较差的氧化铁中含量较高的样品尤其如此。基于磁化率测量或XRD-Rietveld精炼的Mh含量更接近于标准方法提供的Mh含量。发现Mh会在风化的土壤和高Fe2O3含量的土壤中积累。例外的是来自凝灰岩的土壤,其中的Fe2O3含量高(约330 g kg(-1)),Mh水平低(约5.5 g kg(-1))。不论母体材料如何,Mh粒子通常都属于单畴磁行为。但是,它们也可能获得多域特征,这可能是由于赤铁矿的同构取代和聚集作用所致。

著录项

  • 来源
    《Applied clay science》 |2018年第9期|385-394|共10页
  • 作者单位

    Univ Fed Lavras, Dept Soils, BR-37200000 Lavras, MG, Brazil;

    Univ Fed Rio Grande do Sul, Dept Soils, Av Bento Goncalves 7712, BR-91540000 Porto Alegre, RS, Brazil;

    Univ Cordoba, Dept Agron, Edificio C4,Campus Rabanales, E-14071 Cordoba, Spain;

    Univ Fed Rio Grande do Sul, Dept Soils, Av Bento Goncalves 7712, BR-91540000 Porto Alegre, RS, Brazil;

    Univ Fed Lavras, Dept Phys, BR-37200000 Lavras, MG, Brazil;

    Inga Univ Ctr Uninga, Dept Agron, Rodovia PR 317,6114 Parque Ind 200, BR-87035510 Maringa, Parana, Brazil;

    Univ Fed Lavras, Dept Soils, BR-37200000 Lavras, MG, Brazil;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);美国《生物学医学文摘》(MEDLINE);
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

    Soil magnetism; Iron oxides; Tropical soils; Mafic rocks;

    机译:土壤磁性;氧化铁;热带土壤;基性岩;

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号