地质与勘探2018，Vol.54Issue(3)：465-478,14.
贵州盘县架底金矿稀土元素和同位素特征及成矿物质来源探讨
REE and Isotopic Features of the Jiadi Gold Deposit in Panxian County of Guizhou Province and its Ore-Forming Material Source
摘要
Abstract
The Jiadi gold deposit is located in the Mount Emei basalt distribution area of western Guizhou Province. The work for the first time discov-ered primary gold ore bodies in the middle of second member in Mount Emei basalt formation,which occur in interlayer fracture zone dominated by altered volcanic breccia. The ore-hosted surrounding rocks are mainly basalt and tuff,and ore-hosted rocks are mainly altered volcanic breccia. The underly-ing ores are hosted in structural alteration rocks near the unconformity between the Middle Permian Maokou Formation and the Upper Permian Mount Emei basalt formation. This work discussed the relationship between the Jiadi gold ore bodies and surrounding rocks and also the ore-forming material source through REE and hydrogen-oxygen-sulfur isotopes. The ΣREE values of the orebodies range from 151.11×10 -6to 321.52 ×10 -6, the average=221.21×10 -6,much smaller than that of surrounding rocks,LREE/HREE=2.9~8.53,the average=6.84,LaN/YbN=5.55~12.33,the average=9.13,slightly smaller than surrounding rocks. Except for some individual sample with δEu<1,other samples generally have δEu>1,implying the ore-forming fluid may be mainly come from the deep through high temperature and reducing environment. The ore bodies inherit part of the rare earth distribu-tion curve of surrounding rocks,which indicates that part of the ore-forming material may be come from surrounding rocks. The δ34S values of stibnite lie in -0.80‰~ -0.90‰,with extreme difference range of 0.1‰and an average value of -0.85‰;the range of data changes is narrow,and the degree of homogenization is high,mostly around 0‰,indicating that the sulfur of ore-related mineral stibnite may be mainly come from the deep. The quartz hydrogen and oxygen isotope show δDV-SMOW= -70‰~ -56‰and δ18OV-SMOW=23.20‰~23.60‰. Taking 200℃ as the metallogenic temperature of gold deposits in this area,according to the quartz-water fractionation equations,we calculated the δ18OH2O of balance H2O to be 11.49‰~11.89‰in quartz. The plotted diagram shows that the ore-forming fluid is located between magmatic hydrothermal and metamorphic water,indicative of a mixed characteristic. However,there is no metamorphism occurred in this region,and four samples of quartz's δDV-SMOW all fall in normal magma water,which implies that the ore-forming fluid in the Jiadi gold deposit has magma water characteristics.关键词
玄武岩/稀土元素/同位素/成矿物质来源/架底金矿/盘县/贵州Key words
basalt/REE/isotope/ore-forming materialsource/Jiadi gold deposit/Panxian county/Guizhou分类
天文与地球科学引用本文复制引用
赵富远,肖成刚,张兵强,王石华,李俊海,马健..贵州盘县架底金矿稀土元素和同位素特征及成矿物质来源探讨[J].地质与勘探,2018,54(3):465-478,14.基金项目
贵州省地质矿产勘查开发局地质科研项目(编号:黔地矿科合(2014)06号])贵州省地质矿产勘查开发局地质科研项目(编号:黔地矿科合(2017)12号)联合资助. （编号:黔地矿科合(2014）
