Synchrotron‐based infrared microspectroscopy as a useful tool to study hydration states of meteorite constituents
Synchrotron‐based infrared microspectroscopy as a useful tool to study hydration states of meteorite constituents
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基于同步加速器的红外显微光谱作为研究陨石成分水合状态的有用工具
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发表时间：
2006
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通讯作者：
Marina A. Ivanova
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作者：
L. Moroz;M. Schmidt;Ulrich Schade;Takahiro Hiroi;Marina A. Ivanova
翻译后摘要-我们提出的异常碳质碳质岩Dhofar（Dho）225和Dhofar 735的红外（IR）显微镜研究的结果相比，典型的CM 2碳质岩冷Bokkeveld，默里，和Mighei。傅里叶变换红外（FTIR）2.5-14 μm的反射率测量是在传统的抛光切片上使用红外显微镜与同步辐射源进行的。我们证明，基于同步辐射的红外显微光谱是一个有用的，无损的工具，用于研究陨石成分的水化状态原位。我们的研究结果表明，Dho 225和Dho 735的基质脱水相比，典型的CM 2沸石的基质。Dho 225和Dho 735基质的光谱缺乏Cold Bokkeveld、Murray和Mighei光谱中存在的2.7-2.8 μm吸收特征。在Dho 225和Dho 735基质的光谱中，由细粒富铁橄榄石中的Si-O振动引起的光谱特征在10 μm光谱区域占主导地位，而正常CM 2方解石的光谱由层状硅酸盐中的Si-O振动引起的光谱特征占主导地位。我们在Dho 225和Dho 735抛光切片的光谱中没有检测到任何水合相。此外，Dho 225和Dho 735散装粉末的近红外反射光谱显示出与南极变质碳质玄武岩的光谱相似性。我们证实了先前的矿物学，化学和同位素研究结果，表明来自阿曼的两块陨石是第一个非南极变质碳质陨石。
Abstract— We present the results of the infrared (IR) microscopic study of the anomalous carbonaceous chondrites Dhofar (Dho) 225 and Dhofar 735 in comparison to typical CM2 chondrites Cold Bokkeveld, Murray, and Mighei. The Fourier transform infrared (FTIR) 2.5–14 μm reflectance measurements were performed on conventional polished sections using an infrared microscope with a synchrotron radiation source. We demonstrate that the synchrotron‐based IR microspectroscopy is a useful, nondestructive tool for studying hydration states of meteorite constituents in situ. Our results show that the matrices of Dho 225 and Dho 735 are dehydrated compared to the matrices of typical CM2 chondrites. The spectra of the Dho 225 and Dho 735 matrices lack the 2.7–2.8 μm absorption feature present in the spectra of Cold Bokkeveld, Murray, and Mighei. Spectral signatures caused by Si‐O vibrations in fine‐grained, Fe‐rich olivines dominate the 10 μm spectral region in the spectra of Dho 225 and Dho 735 matrices, while the spectra of normal CM2 chondrites are dominated by spectral signatures due to Si‐O vibrations in phyllosilicates. We did not detect any hydrated phases in the spectra of Dho 225 and Dho 735 polished sections. In addition, the near‐infrared reflectance spectra of Dho 225 and Dho 735 bulk powders show spectral similarities to the Antarctic metamorphosed carbonaceous chondrites. We confirm the results of previous mineralogical, chemical, and isotopic studies indicating that the two meteorites from Oman are the first non‐Antarctic metamorphosed carbonaceous chondrites.