A Geochemical Study of Rare Earth and Trace Elements in Cassiterite from Dachang Sn-Polymetallic Ore Field,Guangxi Province  

作　　者：Pan JiahuaInstitute of Mineral Deposits, Chinese Academy of Geological Sciences, Beijing 100037Amstutz G. C.Mineralogisch-Petrogrophisches Institut der Universitat Heidelberg,In Neuenheimer Feld 236, Heidelberg,Germany 

出　　处：《Journal of Earth Science》1993年第1期57-63,共7页地球科学学刊（英文版）

基　　金：The project is supported by Professional Foundation of Geology Carl Duesberg Gesellschaft

摘　　要：Rare earth and trace elements are determined for cassiterite from a vein-type orebody , a lens and a sheeted-type orebody in the Dachang Sn-polymetallic ore field ,Guangxi Province .Cassiterite from the vein-type orebody has rare earth and trace dement characteristics similar to that of Dachang biotite granite of Late Yanshan age, showing an inheritable and a genetic relationship. Cassiterites from the kns and sheeted-vein orebody have rare earth and trace element characteristics greatly different from those of the vein-type cassiterite and the granite,showing distinctly higher contents of the ore-forming elements As, Sb,Zn,Ag etc.and a positive Eu anomaly and a negative Ce anomaly.The difference of rare earth and trace element characteristics for cassiterite from two kinds of orebodies reflects the compositional difference of ore-forming solutions. Authors suggest that the kns and sheeted-vein orebody was of nonmagmatic , mixed with underground hot brine origin , and that this kind of hot brine reacted with Devonian and Predevonian older strata and extraced some ore-forming metals from the strata and finaly empbced along the bedding and interbyer fracture zone etc. on its ascending way driven by the Indonisian orogenic movement . The vein-type orebody was formed chiefly by post-magmatic hydrothermal sobtions derived from magma differentiation of the Dachang biotite granite .Rare earth and trace elements are determined for cassiterite from a vein-type orebody , a lens and a sheeted-type orebody in the Dachang Sn-polymetallic ore field ,Guangxi Province .Cassiterite from the vein-type orebody has rare earth and trace dement characteristics similar to that of Dachang biotite granite of Late Yanshan age, showing an inheritable and a genetic relationship. Cassiterites from the kns and sheeted-vein orebody have rare earth and trace element characteristics greatly different from those of the vein-type cassiterite and the granite,showing distinctly higher contents of the ore-forming elements As, Sb,Zn,Ag etc.and a positive Eu anomaly and a negative Ce anomaly.The difference of rare earth and trace element characteristics for cassiterite from two kinds of orebodies reflects the compositional difference of ore-forming solutions. Authors suggest that the kns and sheeted-vein orebody was of nonmagmatic , mixed with underground hot brine origin , and that this kind of hot brine reacted with Devonian and Predevonian older strata and extraced some ore-forming metals from the strata and finaly empbced along the bedding and interbyer fracture zone etc. on its ascending way driven by the Indonisian orogenic movement . The vein-type orebody was formed chiefly by post-magmatic hydrothermal sobtions derived from magma differentiation of the Dachang biotite granite .

关 键 词：rare earth element trace element  Dachang Sn ore deposits . 

分 类 号：P5[天文地球—地质学]