State analysis of micro area of omphacite inclusions within garnet from eclogite

我们已经证实，拉曼光谱是有用的，作为铁的氧化还原状态的指标，包括辉长岩石榴石。超高压变质带的榴辉岩常显示石英针组成的复合集合体或片层。在石榴石或锆石内的辉石中几乎没有发现，它们被认为避免了逆行变质作用的影响。地温计测温的另一个问题是斜辉石中Fe3+含量的测定。穆斯堡尔光谱和光子工厂中的微xanes （x射线吸收近边结构）是测量Fe3+/Fe2+比值的有效方法。在前者中，矿物分离是必要的，从一个样品中收集光谱需要一天以上的时间，但在微米尺寸的原位分析是可能的，在后者中，除了有限的设备，收集光谱需要不到2h。

We have verified that Raman spectrums are useful as an indicator for the redox state of iron in omphacite included within garnet from eclogites. Eclogites from ultrahigh-pressure metamorphic belts often show symplectitic aggregate or lamellae composed of quartz needles. They are hardly observed in omphacite included within garnet or zircon, those are considered to have avoided the influence of retrograde metamorphism. Another problem in temperature estimation using geothermometer is the determination of Fe3+content in clinopyroxene. Mossbauer spectroscopy and micro-XANES (X-ray absorption near edge structure) in photon factory are effective for the measurement of the Fe3+/Fe2+ratio. In the former, mineral separation is necessary and it takes more than one day to collect spectra from one sample, but in situ analysis at the micron size is possible and it takes less than 2h to collect spectra in the latter except limited facilities.