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对区域变质程度不同的两类变质岩中铀的分布进行了研究。一类岩石是变质程度低的绿色片岩一闪岩相,另一类是变质程度较高的闪岩一麻粒岩相。对碱性玄武岩中一些中一高压形成的麻粒岩包体也作了分析。岩石中铀的丰度在低于麻粒岩相的变质作用中没有受到影响。与闪岩相岩石相比,麻粒岩是贫铀的。两类岩石中铀的分布也有差异,闪岩相岩石中的铀主要是存在于铁镁矿物的裂隙和解理面上以及副矿物中,而在麻粒岩中,铀主要存在于副矿物中。看来,麻粒岩的贫铀是由于铀的逸失所致,这些铀不是存在于副矿物或主要造岩矿物的结晶格架中,而是在裂隙中,它们在脱水作用时期被迁移的水溶液带走。
The distribution of uranium in two types of metamorphic rocks with different degree of regional metamorphism was studied. One kind of rock is green schist rock amphibolite facies with low degree of metamorphism and the other kind is amphibolite-granulite facies with higher degree of metamorphism. Some granulite inclusions formed by some middle-high pressure in basaltic basalts were also analyzed. The abundance of uranium in the rock is unaffected by the metamorphism below the granulite facies. Granulites are depleted of uranium compared to amphibolite rocks. There are also differences in the distribution of uranium between the two types of rock. Uranium in the rock of the amphibolite is mainly present on the fissures and cleavages surfaces of iron-magnesium minerals and in accessory minerals, whereas in the granulites, uranium is mainly present in the accessory minerals. It appears that the depleted uranium from granulite is due to the escape of uranium, which is not found in the crystal lattice of accessory minerals or major rock-forming minerals but rather in the fissures, which are migrated in the fissures go.