投稿时间：2012-08-18
修订日期：2013-07-23
网络发布日期：2013-10-29
中文摘要:新疆白杨河铀铍矿床是近年来发现的亚洲最大的次火山岩型铀铍矿床,该矿床铀铍矿化主要与萤石化密切相关。在野外地质工作和室内分析的基础上,根据不同期次萤石的颜色、结构构造及相互穿插关系将萤石脉划分为4期。4期萤石流体包裹体均一温度变化范围为90℃到176℃,均一温度峰值为120~150℃,表明该矿床为低温热液矿床。萤石中流体包裹体多数为气相CO2-水溶液两相(V-L)包裹体,在降温过程中形成了CO2笼合物。文章采用假设液相CO2含量无限接近于0的方法计算气相CO2-水溶液两相(V-L)包裹体的盐度,获得的成矿流体盐度w(NaCleq)范围为4.69%~19.72%,每一期萤石流体包裹体的平均盐度w(NaCleq)均在10%左右。不同期次萤石流体包裹体均一温度主峰之间差别较小,总体经历了波动性演化,平均盐度之间差别较小。流体盐度特征表明,成矿流体来源不是单一的大气降水,推测高盐度的岩浆水参与了成矿作用。
Abstract:The Baiyanghe deposit is the largest sub-volcanic U-Be deposit discovered recently in Asia. Fluorite, which is the main associated mineral of U, Be minerals, has been elaborately divided into four stages according to the colors, textures and the crosscut relationships. Fluid inclusion experiment was conducted to obtain information of ore-forming fluid. The results show that homogenization temperatures of fluid inclusions at different stages of fluorite veins range from 90℃ to 176℃, and main homogenization temperature peaks range from 120~150℃,indicating that the Baiyanghe U-Be deposit is an epithermal deposit. The majority of inclusions from four stages of fluorite are vapor CO2-liquid H2O two phase inclusions and CO2 clathrate formed during the cooling of the inclusions. However,there is no method to calculate salinities of such inclusions. An assumption is made in this paper that liquid CO2 content in the vapor CO2-liquid H2O two-phase (V-L) inclusions is infinitely close to 0 to get salinities of such inclusions. The obtained salinities w(NaCleq) range from 4.69% to 19.72% for all inclusions and the average salinity w(NaCleq) of each stage of fluorite is approximately 10%. The homogenization temperatures varied slightly and the average salinities changed nominally. Therefore, meteoric water could not be the only source of ore-forming fluid. Taking the geological setting into account, the authors hold that high salinity magmatic water might have been an important source of ore-forming fluid to form a mixed salinity w(NaCleq) of around 10%.
文章编号：
中图分类号：P618.14;P618.72
文献标志码：
基金项目:本文得到核工业地质局科研项目和中国科学院"百人计划"项目共同资助
引用文本：
毛伟,王果,李晓峰,王谋,肖荣.2013.新疆白杨河铀铍矿床流体包裹体研究[J].矿床地质,32(5):1026~1034MAO Wei,WANG Guo,LI XiaoFeng,WANG Mou,XIAO Rong.2013.A study of fluid inclusions in Baiyanghe U-Be deposit, Xinjiang[J].Mineral Deposits32(5):1026~1034
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