不久前曾经认为,铀对于霞石正长岩并没有代表性,并且在共中存在之数量通常比在花岗岩中要少得多。但是,近年来所进行的罗沃捷尔鹼性岩放射性之研究表明,其中铀的平均含量比火成岩及花岗岩类中平均含量大致高三倍。继Л.В.柯母列夫研究之后,我们对岛拉尔及南穆果 It has been recently accepted that uranium is not representative of nepheline syenite and that the amount of co-existence is usually much less than that of granite. However, a recent study of Roverdall alkaline rock radioactivity shows that the average content of uranium therein is approximately three times higher than the average content of igneous and granitoids. Following Л.В. Komainlev’s research, we are on Isla and Nammu