中国矿物岩石地球化学学会第三届理事会工作报告

中国矿物岩石地球化学学会第三届理事会工作报告（１９８９～１９９４）秘书长李加田各位代表：现在我代表第三届理事会向大会汇报本届理事会任期内的工作和今后工作的设想。第三届理事会是１９８８年第三次全国会员代表大会上产生的，按会章规定应于１９９３年换届，考虑...     

司幼东(1920～1968)

司幼东,河北省唐山市人,我国著名稀有元素地球化学家.1942年毕业于北京大学,曾历任北京大学、山东大学助教、讲师、副教授.1951年赴前苏联留学,并获副博士学位.1955年回国后历任中国科学院地质研究所和地球化学研究所副研究员、研究员、研究室副主任、主任、中国科学院研究生部委员等职.     

花岗岩浆结晶过程晚期铌、钽富集成矿的地球化学机理探讨

The mechanism of Nd.Ta-mineralixation is diseussed in the light of the properties of Nb-,Ta-complexes in different phases.Experiments show that Nb and Ta are essentially enriched in the melts when Nb-,Ta-bearing albite granites are completely melted(800-850℃）and in equilibrium with a HF-bearing vapor phase,It is also demonstrated from the experiments,that hydrolysis of Nb-,Ta-flourine complexes in aqueons solutions takes place with inereasing temperature,reaching a maximum value in the vicinity of critical temperature and becoming stable under supercritical conditions.Under this circumstance,Nb-,Ta-complexes can be trausported in the vapor phase,Ta exhibits a great,ability of transport in vapor phase as compared with Nb,while Nb is more soluble than Ta under hydrothermal conditions.The authors hold,on the basis of experiments and field observations,that Nb-,Ta-mineralixation is related to the proeess of crystllization-differentiation of lowmelting granitic magma which is rich in flourine.water and alkalis,as well as to the metasoatism during the late stage,pH ariation is also dealt with during Nb-.Ta-mineralization.