Spectroscopic and TEM studies of phyllosilicates in carbonaceous chondrite

碳质球粒陨石中页硅酸盐的光谱和 TEM 研究

• 批准号: 08640600
• 负责人: NOGUCHI Takaaki
• 金额: $ 1.41万
• 依托单位: IBARAKI UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08640600/
• 关键词: visible light spectroscopy; L^* a^* b^* color system; sheet silicate; CM chondrite; serpentine; chlorite; aqueous alteration; L^*a^*b^*表色系; L^*a^*b^*色系; 蛇石; 層状珪酸塩鉱物; spinach; 顕微可視分光法; 変質

CM chondrites experienced aqueous alteration. Due to the aqueous alteration, mesostses in chondrules were replaced by phyllosilicates. Such phyllosilicates are various in colors, for example, green, yellowish green, yellowish brown, reddish brown, and so on. In this study, phylloslicates in Murchison, Murray, Y75293, Y791 198, Mighei, Nogoya, and Y82042 were investigated by visible light spectroscopy and electron microprobe analysis. Colors of such phyllosilicates were compared quantitatively by using L*a*b* color system. Compared with compositional variation of the phyllosilicates among differently altered CM chondrites, changes in colors in the phyllosilicates are complex. Complexity of changes in color depends on both the differences in minerals which suffered alteration and redox states during phyllosilicate formation. Differences in colors in phyllosilicates are due to broad absorption band around 700 nm (probably due to IVCT between Fe^<3+> and Fe^<2+>) and a shoulder around 450-500 nm (probably due to six coordinated Fe^<3+> cations). It is expected that green phyllosilicates and reddish brown ones have different Fe^<3+>/Fe^<2+> ratios. We are now seeking a convenient method to acquire Fe^<3+>/Fe^<2+> ratios in serpentine-group minerals.

CM藻经历了水蚀变。由于水蚀变，球粒中的中孔被层状硅酸盐所取代。本文对Murchison、Murray、Y 75293、Y 791 198、Mighei、Nogoya和Y82042等7个样品的层状硅酸盐进行了可见光光谱和电子探针分析。用L*a*B* 颜色系统定量比较了这些层状硅酸盐的颜色。与不同蚀变程度的CM榴辉岩中层状硅酸盐的成分变化相比，层状硅酸盐的颜色变化是复杂的。颜色变化的复杂性取决于层状硅酸盐形成过程中遭受蚀变的矿物和氧化还原状态的差异。层状硅酸盐的颜色差异是由于700 nm附近的宽吸收带（可能是由于Fe^<3+>和Fe^<2+>之间的IVCT）和450-500 nm附近的肩峰（可能是由于六个配位的Fe^<3+>阳离子）。预计绿色层状硅酸盐和红棕色层状硅酸盐具有不同的Fe^<3+>/Fe^<2+>比率。我们正在寻找一种简便的方法来测定蛇纹石类矿物中的Fe^<3+>/Fe^<2+>比值。

项目成果

T.Noguchi et al.: "Spectroscopic and TEM study of phyllosilicates in CM chondnite" Meteoritics and planetary Science.

T.Noguchi 等人：“CM 球粒陨石中层状硅酸盐的光谱和 TEM 研究” 陨石学和行星科学。

T.Noguchi et al.: "Spectroscopic and SQUID study of serpentine group minerals" Mineralogical Journal.

T.Noguchi 等人：“蛇纹石族矿物的光谱和 SQUID 研究”矿物学杂志。

M.Kimura, T.Noguchi, Y.Lin, and O.Wang: "Synthetic and natural rock systems (eds.Oupta, Onuma, Atima)" Allied Publishing Led., 283 (1997)

M.Kimura、T.Noguchi、Y.Lin 和 O.Wang：“合成和天然岩石系统（编辑 Oupta、Onuma、Atima）” Allied Publishing Led.，283 (1997)

T.Noguchi: "Ultramicrotomy and its application to the study of meteorites and cosmic austs." Chikyu kagaku. 32. 215-223 (1998)

T.Noguchi：“超薄切片术及其在陨石和宇宙奥斯特研究中的应用。”

野口高明・今栄直也: "隕石と宇宙塵の鉱物学・岩石学" 地球化学. 32. 175-184 (1988)

Takaaki Noguchi 和 Naoya Imaei：“陨石和宇宙尘埃的矿物学和岩石学”地球化学 32. 175-184 (1988)。