大别-苏鲁超高压变质岩研究新思路: 偏光显微镜阴极发光技术的应用

利用偏光显微镜阴极发光技术可观察到其他常规成分结构测试法不易识别或容易忽略的多种矿物的生长结构, 该技术是进行后续成分分析的有效预研究手段, 可为重建矿物形成演化过程提供重要信息.该技术在国际岩石矿物学、油气储层及矿床学领域应用广泛, 但在变质岩研究领域的应用较薄弱.综述该技术在国际超高压变质岩研究领域的应用, 并利用其对大别-苏鲁超高压变质带经典地区的超高压榴辉岩、云母片岩、大理岩进行初步研究, 讨论它在多期微细矿物相快速鉴别、生长环带、微量元素分布规律、双晶纹、出溶结构等内部结构表征方面的应用价值和前景.偏光显微镜阴极发光技术与拉曼光谱、扫描电镜、电子探针等分析技术相结合, 可为我国超高压变质岩的研究开辟和扩展一条新思路. 

A New Perspective for Research of Dabie-Sulu Ultrahigh-Pressure Metamorphic Rocks: Application of Optical Microscope-Based Cathodoluminescence

With the use of optical microscope-based cathodoluminescence (OM-CL), many kinds of growth textures of minerals can be observed, which are either indiscernable or to be omitted easily with other routine analytical methods. OM-CL is an effective pre-research technique prior to other follow-up component analysis, which can provide important information for reconstructing formation and evolution processes of minerals. This technique has wide-spread applications in international petromineralogy, oil and gas reservoir and mineral deposits, but is relatively weak in metamorphic rocks. The applications of OM-CL in the UHP (ultra high power) metamorphic rocks are reviewed in this paper, as well as preliminary studies by OM-CL on ultrahigh-pressure eclogites, micaschist and marble at classical areas in the Dabie-Sulu UHP metamorphic belt. And its application and prospect in the fast identification of multi-phase tiny mineral facies and internal structural characterization, including growth zoning, distribution of trace elements, twinning and exsolution texture are discussed. A new perspective for our research on ultrahigh-pressure metamorphic rocks can be developed when combining OM-CL with mineral chemistry analysis techniques such as Roman spectrum, scanning electron microscope (SEM) and electron probe micro-analyzer (EPMA).