某地含黑稀金矿花岗岩脉的初步研究

An investigation has been conducted of the geological and geochemical characteristics of euxenitebearing granitic veins found for the first time in China. It is shown that these veins are late intrusives in an Yah Shah granitic complex at a geosyclinal folded zone and composed mainly of medium grained biotite granite in which the local enrichment of euxenite during the late period of magmatic activity is obvious. The mineral has been found to be metamiet and chemically represent a transitional member between euxenite and polyclase. This study has provided a typical example that gralitic melts with a lower initial content of rare elements would contribute significantly to the local enrichment of rare element minerals under special external conditions.