大水沟碲矿中楚碲铋矿显微文像结构——交代成因新证据  

New Evidence for the Metasomatism of Graphic-myrmekitic Textures of Tsumoite in the Dashuigou Tellurium Deposit

作　　者：张佩华[1] 赵振华[1] 王一先[1] 曹志敏[2] 赖鸣远[3] 

机构地区：[1]中国科学院广州地球化学研究所,510640 [2]成都理工学院,610059 [3]南京大学内生金属矿床成矿机制研究国家重点实验室,210093

出　　处：《地质论评》2000年第3期318-323,共6页Geological Review

基　　金：国家自然科学基金 (编号49633no);国家攀登计划 (编号95-预-25)的成果;南京大学内生金属矿床成矿机制研究国家重点实验室资助

摘　　要：大水沟楚碲铋矿的产状及其文像矿物形态既有普遍的“交代”现象,也有明显的“出溶”特征。文像磁黄铁矿与伴生或残余的磁黄铁矿成分的相似性,以及文像矿物在分布和成分上与出溶动力学实验以及理论模式的差异,表明形成显微文像结构的根本原因为富碲、铋流体交代早期磁黄铁矿。楚碲铋矿及其显微文像结构的特征取决于交代环境的“封闭”程度:强度弱、无铁带出的交代形成具明显“交代”特征的楚碲铋矿;当交代强度大、环境封闭时,交代残余矿物在交代流体中发生“溶解”,形成的文像结构往往具有“出溶”特征。Tsumoite in the Dashuigou tellurium deposit shows features of both ubiquitous metasomatism and exsolution by its occurrence and graphic-myrmekitic textures it contains. The graphic-myrmekitic pyrrhotites of the tsumoite have compositions similar to those of early stages, but their spatial elongation and size change are in contradiction with experiments and theoretical models. This suggests that the graphic-myrekitic textures be essentially metasomatic products of earlier pyrrhotites altered by Te-, Bi-rich fluids. The minor variation of the textures is dependent on variant metasomatic intensity and closeness of the corresponding environments. Week alteration without mobility of iron will produce tsumoites with typical metasomatic features, whereas complete alteration in a stable environment can dissolve early minerals in the fluids, which produce exsolution-oriented graphic-myrmekitic texture.

关 键 词：楚碲铋矿 磁黄铋矿 显微文像结构 碲矿 交代成因 

分 类 号：P618.6[天文地球—矿床学]