相山破火山口内中低温热液铀矿床的铀钍类质同像研究

作者在研究火山岩铀矿床的过程中,发现产于相山破火山口内的某些中低温热液铀矿床的主要工业矿物为含钍沥青铀矿等铀钍矿物。这些铀钍矿物的矿物学研究和实验室内模拟中低温热条件下人工合成含钍沥青铀矿的验实结果都证明,在含钍沥青铀矿和其它铀钍矿物中,钍是以类质同像置换形式存在的,这表明,铀、钍不但能够在高温条件下形成广泛的类质同像置换,而且在某种特定的地球化学环境中,中低温热液条件下也可以出现铀、钍类质同像置换,形成特定的铀钍矿物系列。这一发现对进一步发展铀钍地球化学理论和认识某些矿床成因都是有重要意义的。

THE STUDY OF URANIUM AND THORIUM ISOMORPHISM IN EPI-MESOTHERMAL URANIUM DEPOSITS OF XIANGSHAN CALDERA

During the study of epi-mesothermal uranium deopsits in Xiangshan caldera, several uranium and thorium minerals, including thorium-bearing pitchblende, uranothorite, thorium-bearing brannerite, etc. , have been found. The mineralogical study and experimental results of artificial thorium-bearing pitchblende by laboratory simulation under epi-mesothermal conditions prove that in thorium-bearing pitchblende and other uranium and thorium-bearig minerals, thoriurium exists in the form of isomorphic replacement. This shows that uranium and thorium isomorphic replacement occurs not only in hydrothermal conditions, but also in epi-mesothermal conditions in certain specific geochemical environments, forming specific uranium and thorium mineral series. The discovery is of importam significance to the further theoritical development of uranium and thorium geochemistry and genetic study of certain uranium deposits.