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现代地质 ›› 2012, Vol. 26 ›› Issue (2): 277-285.

• 矿床学 • 上一篇    下一篇

贵州丫他卡林型金矿床流体包裹体特征及其成矿意义

 吴程赟1, 顾雪祥1, 刘丽1, 李保华2, 程文斌2, 章永梅1, 彭义伟1   

  1. 1  中国地质大学 地球科学与资源学院,北京100083;2  成都理工大学 地球科学学院,四川 成都610059
  • 收稿日期:2011-10-22 修回日期:2012-01-11 出版日期:2012-04-20 发布日期:2018-09-19
  • 作者简介:吴程赟,男,硕士研究生,1987年出生,矿产普查与勘探专业,主要从事矿床学和矿床地球化学的研究。Email: wucyyy@163.com。
  • 基金资助:

    国家自然科学基金重点项目(40930423)

Fluid Inclusion Characteristics of Yata Carlintype Gold Deposit,Guizhou Province and Its Metallogenic Significance

 TUN  Cheng-Bin-1, GU  Xue-Xiang-1, LIU  Li-1, LI  Bao-Hua-2, CHENG  Wen-Bin-2, ZHANG  Yong-Mei-1, BANG  Xi-Wei-1   

  1. 1  School of Earth Sciences and Resources, China University of Geosciences, Beijing100083, China;2  College of Earth Sciences, Chengdu University of Technology, Chengdu, Sichuan610059, China
  • Received:2011-10-22 Revised:2012-01-11 Online:2012-04-20 Published:2018-09-19

摘要:

黔西南丫他金矿床是典型的沉积岩容矿的微细浸染型金矿床。从流体包裹体的角度,探讨了丫他金矿床成矿的温度压力条件和流体演化。各阶段石英、雄黄的流体包裹体岩相学和显微测温研究结果表明:主成矿阶段包裹体主要类型有H2O、CO2和CO2-H2O包裹体,流体包裹体组合呈现CO2-H2O不混溶的特征,晚成矿阶段包裹体类型主要为H2O包裹体;从主成矿阶段到晚成矿阶段,流体包裹体均一温度由139~268 ℃变化至121~194 ℃,盐度由2.9%~7.4 %变化至2.7%~6.6 %。根据共存CO2包裹体和H2O包裹体的等容线计算法,还原主成矿期包裹体捕获温度为260~294 ℃,捕获压力为59~98 MPa。对比不同类型金矿床中的富CO2流体特征,指出黔西南卡林型金矿床中存在的富CO2流体可能在金的搬运过程中起到一定的作用,CO2-H2O相分离可能是导致矿质沉淀的主要原因。

关键词: 流体包裹体, 成矿流体, 丫他金矿床, 卡林型, 贵州

Abstract:

Yata gold deposit is a typical sediment hosted disseminated gold deposit in southwestern Guizhou. Based on the data from fluid inclusions, we discuss the temperature and pressure conditions and the fluid evolution in the ore forming process. Results from petrographic observation and fluid inclusion microthermometry study of gangue minerals in different stages give us the following conclusions: fluid inclusions in the main mine ralizing stage can be divided into three categories including H2O, CO2 and CO2-H2O inclusions, which indicates the immiscibility of the ore forming fluid; while fluid inclusions in the late mineralizing stage are mainly H2O inclusions; homogenization temperatures of H2O inclusions in the main mine ralizing stage vary from 139 to 268 ℃, salinities range from 2.9% to 7.4%, while homogenization temperatures of H2O inclusions in the late mineralizing stage vary from 121 to 194 ℃, and salinities range from 2.7% to 6.6%. According to the simultaneous solution of isochoric formulas derived from H2O inclusions and CO2 inclusions, the capture temperatures of inclusions in the main mineralizing stage vary from 260 to 294 ℃, while capture pressures range from 59 to 98 MPa. Based on the comparison of characteristics of CO2 rich fluids in different types of gold deposits, we conclude that CO2 rich fluid in Carlin type gold deposits in southwestern Guizhou may play a role in the transportation of gold, and that phase separation between CO2 and H2O could be the cause for gold deposition.

Key words: fluid inclusion, ore forming fluid, Yata gold deposit, Carlin type, Guizhou