风化作用对铁陨石矿物学特征影响的探讨

发布时间：2018-01-28 19:07

本文关键词： 铁陨石 X射线衍射磁性测试风化作用　出处：《岩石矿物学杂志》2014年S2期 　论文类型：期刊论文

【摘要】：本文对南丹IIICD铁陨石的矿物学特征进行了研究,并与同为铁陨石但化学分类不同的阿根廷IAB铁陨石和西伯利亚IIB铁陨石进行了对比,重点探讨了风化作用对铁陨石矿物学特征的影响。首先用偏光显微镜、静水称重、扫描电镜观察了样品的基本矿物学特征和微形貌特征,然后用振动式样品磁强计、X射线衍射与电子探针能谱半定量测试研究了样品的磁学性质、物相和化学组成。研究结果表明,南丹铁陨石在较强的自然风化作用下,光泽变弱为土状光泽,相对密度降低;风化产生的反铁磁性物质会使陨石的磁性下降;另外,样品表面物相组成也发生较大变化,以针铁矿(FeOOH)和磁铁矿(Fe_3O_4)等铁的次生矿物为主;但风化壳以下的矿物物相及化学成分均未发生明显变化,以Fe、Ni为主的铁纹石、镍纹石物相存在。
[Abstract]:In this paper, the mineralogical characteristics of the IIICD iron meteorite in Nandan are studied and compared with the iron meteorites of Argentina IAB and Siberia IIB which belong to the same iron meteorites but have different chemical classification. The effect of weathering on the mineralogical characteristics of iron meteorites was discussed. Firstly, the basic mineralogical characteristics and micromorphology of the samples were observed by polarizing microscope, hydrostatic weighing and scanning electron microscope. The magnetic properties, phase and chemical composition of the samples were studied by X-ray diffraction and electron probe spectroscopy. Under the strong natural weathering, Nandan iron meteorite has a weak luster and a lower relative density. The antiferromagnetic material produced by weathering decreases the magnetism of meteorites. In addition, the surface phase composition of the samples also changed greatly, such as FeOOH (goethite) and Fe3O4 (magnetite). However, the mineral phase and chemical composition below the weathering crust did not change obviously.
【作者单位】：造山带与地壳演化教育部重点实验室北京大学地球与空间科学学院;中国地质大学珠宝学院;
【分类号】：P185.83;P578.12
【正文快照】： 陨石指从宇宙空间降落到地球表面并保持其原对铁陨石的影响并未提及。南丹铁陨石本携带着重始结构的固态物质。据统计,每年降落到地球上的要的宇宙信息,但在降落后经历了近500年物理化陨石约有500个,降落到陆地上的陨石仅有150个学环境的变迁,矿物学特征已有所改变。为研究风

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