硅酸盐熔体中橄榄石晶体的发育过程

早在十九世纪七十年代,也就是显微镜刚用于岩石学和矿物学的时代,某些基性岩,超基性岩的喷出物中的橄榄石所具有的特殊形态即引起一些著名的岩石学家和矿物学家的注意。

THE PROCESS OF CRYSTAL DEVELOPMENT OF OLIVINES IN SILICATE MELTS

The process of crystal development of the olivines in the slags and melts of casting stone is discussed. The conclusion may be drawn as follows:(1) The olivines develope into euhedral or subhedral grains in the slowly cooling silicate melts, but give rise to long prismatic skeletons during slightly supercooling, and to dendritic skeletons during more stronger supercooling.(2) The a-axis elongated prismatic -skeletons were formed by one of the two "crystal cells". "O-shaped", "θ-shaped", and "H-shaped" structures were shown on sections cut across the skeletons, which reveal the complex development history from the crystal cells to the skeletons.(3) The development of the dendritic crystals is as follows. Firstly, the crystals were built up along the R001 vector, then along the R111, R102, and R111 vectors, and finally along the R011 the R001 and R011 vectors.