摘要
锡石在花岗质熔体中的溶解度 ,是阐明花岗岩全岩型锡矿成因的关键。文章设计了以结晶温度和结晶时间为参数的两组熔化_结晶实验 ,试图模拟锡石在岩浆结晶分异过程中的动态变化 ,并在花岗岩_HF_H2 O体系的高温高压实验结果基础上 ,讨论花岗质熔体中SnO2 含量与结晶温度和时间的关系。实验结果表明 :①在岩浆条件下可以形成锡石 ;②随着结晶温度的降低和时间的加长 ,熔体中SnO2 含量先升高后降低 ,表明其经历了由不饱和到过饱和 。
Though much geological evidence suggests that there exists magmatic cassiterite in rare_metal bearing granite, the origin of granite whole rock type cassiterite deposit remains in long_standing controversy due to lack of experimental data. One of the key problems in its origin is the solubility of cassiterite in granitic melt. Here the authors designed two sets of melting and crystallization experiments to model a dynamic change of tin concentration during the crystallization_fractionation process controlled by crystallization temperature and time duration. On the basis of high T_P experiments in the granite_HF_H 2O system, the relationship of SnO 2 concentration to crystallization temperature and time duration in granitic melt is revealed. The results indicate that the SnO 2 concentration in granitic melt with temperature decrease and time duration shows a regular change. The system proceeds from a tin_undersaturated condition to a tin_oversaturated condition, during which the cassiterite is crystallized from the melt as a magmatic mineral.
出处
《矿床地质》
CAS
CSCD
北大核心
2002年第4期393-398,共6页
Mineral Deposits
基金
国家自然科学基金 (编号 :49873 0 17)
国家教育部高校博士点基金 (编号 :19990 2 842 0 )
南京大学成矿作用国家重点实验室开放课题 (编号 :0 5 992 5 )资助
