花岗岩型铀矿床的三种成矿模式及其找矿意义

THREE KINDS OF GENETIC MODELS FOR GRANITE TYPE URANIUM DEPOSITS AND THEIR SIGNIFICANCE IN SEARCH OF DEPOSITS

花岗岩型铀矿床的成因是多种多样的,作者认为可用“演化成矿”、“活化成矿”及“演化和活化混合成矿”三种成因模式概括华南花岗岩型铀矿床的成矿过程。对三种模式的成矿机理及找矿意义的研究表明,与不同成因系列产铀花岗岩有关的铀矿床成因专属性存在着差别。与改造型产铀花岗岩有关的铀矿床成因类型较多,上述三种成因模式均可见到,而与同熔型产铀花岗岩有关的铀矿床则以“演化成矿”为主。属不同成矿模式的铀矿床其铀富集机理和成矿过程也不尽相同,故其找矿判别标志也有所差异。

The geneses of granite type uranium deposits are various. It may be considered that the mineralization processes of granite type uranium deposits, in South China, can be summarized by three kinds of genetic models, i.e.,“evolution mineralization”,“mobilization mineralization”and“evolution-mobilization”. An investigation of metallogenetic mechanisms and the significance of these models in search of deposits shows that there are differene in the genetic speciality of uranium deposits associated with different genetic granites. There are more genetic types of uranium deposits related to transformation type granites than uranium deposits related to syntexis type granites. In the former case, all three genetic models of uranium deposits can appear. In the latter case, however, only evolution mineralization is dominant. The uranium enrichment mechanisms and mineralization of the uranium deposits corresponding to different models are not always identified with each other, so their recognition criteria are also different.