发现天然产高压相矿物的微矿物学途径

迄今人们已经在陨石中发现了11种高压相矿物,它们是地幔过渡带和下地幔的主要矿物相,其中有8种是最近5年来随着研究工作的深入和微矿物学 技术的不断发展而连续发现的。1995年在寺巷口陨石中发现了属于地幔过渡带的林伍德石、 瓦茨利石、镁铁榴石、镁方铁矿和磷酸盐A相,随后又参与了陨石中其它新高压同质多像矿 物的发现和研究。在工作中使用了多种近代微矿物学技术,特别是激光拉曼探针和原位X射线显微分析技术在鉴定中起了关键作用。

Micro-Mineralogical Approaches in Discoveries of Natural High-Pressure Minerals

high-pressure minerals have been found in naturally shocked chondrites.These minerals are main phases of the Earth mantle transition zone and the lower mantl e.Since the grain sizes of the high-pressure minerals are very small, only 1-2 to several tens microns, various micro-mineralogical techniques have been deve loped for study and identification of these tiny minerals,espicially the laser m icro-Raman spectroscopy and the Brucker in-situ micro analytical X-ray system become the key technical approaches for identification of fine-grained new min erals in general, and the tiny new high-pressure polymorph minerals in thin sec tions of meteorites in particular. Some examples in discovery of new mineral pha ses in shock melt veins of chondrites using these techniques are demonstrated by the authors in this paper.