Organic thermometry for chondritic parent bodies
Organic thermometry for chondritic parent bodies
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DOI：
10.1016/j.epsl.2008.05.008
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发表时间：
2008-07-30
影响因子：
5.3
通讯作者：
Mysen, B. O.
中科院分区：
文献类型：
--
作者：
Cody, G. D.;Alexander, C. M. O'D.;Mysen, B. O.
一个独特的光谱特征已被确定在25个不同的陨石不溶性有机物质（IOM）的研究跨越多个化学类别，群体和岩石类型，使用碳X射线吸收近边结构（XANES）光谱。这一特征的强度，一个1 s-sigma * 激子，似乎提供了一个精确的测量母体变质。该激子的强度也显示出与通过固态C-13 NMR观察到的大的负顺磁位移相关。实验表明，在加热原始IOM被转化为材料，是无法区分的热处理的铌酸锂，包括发展的1 s-sigma * 激子。一个热动力学表达式推导出前面的实验数据，允许的1 s-sigma * 激子的强度被用来估计的有效温度随时间的积分。一个很好的相关性之间观察到的1 s-sigma * 激子和先前公布的显微拉曼光谱数据的强度。这些数据提供了一个自洽的有机衍生的温标的目的，校准拉曼的测温表达式。(C)2008 Elsevier B. V.保留所有权利。
A unique spectroscopic feature has been identified in a Study of twenty-five different samples of meteoritic insoluble organic matter (IOM) spanning multiple chemical classes, groups, and petrologic types, using carbon X-ray Absorption Near Edge Structure (XANES) spectroscopy. The intensity of this feature, a 1s-sigma* exciton, appears to provide a precise measure of parent body metamorphism. The intensity of this exciton is also shown to correlate well with a large negative paramagnetic shift observed through solid state C-13 NMR. Experiments reveal that upon heating primitive IOM is transformed into material that is indistinguishable from that in thermally processed chondrites, including the development of the 1s-sigma* exciton. A thermo-kinetic expression is derived front the experimental data that allows the intensity of the 1s-sigma* exciton to be used to estimated the effective temperature integrated over time. A good correlation is observed between the intensity of the 1s-sigma* exciton and previously published microRaman spectral data. These data provide a self-consistent organic derived temperature scale for the purpose of calibrating Raman based thermometric expressions. (C) 2008 Elsevier B.V. All rights reserved.