四川木里梭罗沟金矿床成矿流体特征:流体包裹体及C-H-O同位素的证据  

CHARACTERISTICS OF ORE-FORMING FLUID IN SUOLUOGOU GOLD DEPOSIT,MULI,SICHUAN PROVINCE:EVIDENCE OF FLUID INCLUSIONS AND C-H-O ISOTOPES

作　　者：张文林[1] 席孝义 余旭辉[1] 文怀忠 林鑫[1] 魏永峰[1] 曹华文[2] Zhang Wenlin;Xi Xiaoyi;Yu Xuhui;Wen Huaizhong;Lin Xin;Wei Yongfeng;Cao Huawen(Regional Geological Survey Team,Sichuan Bureau of Geological Exploration and Exploration of Mineral Resources,Chengdu,Sichuan 610213,China;Chengdu Center of China Geological Survey,Chengdu,Sichuan 610083,China)

机构地区：[1]四川省地质矿产勘查开发局区域地质调查队,四川成都610213 [2]中国地质调查局成都地质调查中心,四川成都610081

出　　处：《矿物岩石》2020年第3期80-91,共12页Mineralogy and Petrology

基　　金：国家自然科学基金项目(41802095);四川省地质矿产勘查开发局科技计划项目:甘孜-理塘断裂带梭罗沟金矿成矿规律及成矿预测研究。

摘　　要：梭罗沟金矿床是目前甘孜-理塘金矿带上查明资源储量最大的岩金矿床。该矿床的矿床成因研究薄弱且争议较大。本次研究在矿床地质特征的基础上,采集9件样品进行流体包裹体、石英H-O同位素和方解石C-O同位素的研究,分析其矿床成因和矿床类型。结果表明,梭罗沟金矿床的成矿流体以富液相水溶液包裹体和CO2-H2O型三相包裹体为主,均一温度集中在200~300℃,盐度范围w(NaCleq)为4%~12%,成矿深度为10~12km。属于中温低盐度的H2O-CO2-NaCl型流体。梭罗沟金矿床成矿流体的δ13 CV-PDB范围为-5.8‰^-5‰,平均值为-5.2‰;δDV-SMOW范围为-79.3‰^-91.5‰,平均值为-86.4‰,δ18 OV-SMOW范围为5.4‰~11.5‰,平均值为9.2‰。C-H-O稳定同位素结果均与岩浆和变质热液流体的同位素接近,而与其它流体储库来源区别较大。梭罗沟金矿床赋存于蚀变中—基性火山岩块中,矿体受控于脆—韧性剪切带。结合流体包裹体与C-H-O同位素特征,本次研究认为梭罗沟是典型的造山型金矿床。The Solougou gold deposit in Muli County of western Sichuan is the largest rock gold deposit in the Ganzi-Litang gold belt.However,the study on the genesis of the deposit is insufficient and controversial,which seriously holds back the fllowing exploration work.Based on geological characteristics of the Solougou gold deposit,9samples were collected for the study of fluid inclusion,quartz H-O isotope and calcite C-O isotope,so as to analyze the genesis and type of the deposit.The results show that the ore-forming fluids of the Sologou gold deposit are mainly liquid-rich aqueous inclusions and CO2-H2O three-phase inclusions.The homogenization temperature is concentrated at 200-300℃,the salinity ranges are 4%-12%w(NaCleq),and the ore-forming depth is 10-12km.It belongs to H2O-CO2NaCl fluid with medium temperature and low salinity.The range ofδ13 CV-PDBof ore-forming fluid in Sologou deposit is-5.8‰--5‰,and the average value is-5.2‰.δDV-SMOWranges from-79.3‰to-91.5‰,with an average value of-86.4‰,andδ18 OV-SMOWranges from 5.4‰to 11.5‰,with an average value of 9.2‰.The results of C-H-O stable isotopes are close to those of magmatic and metamorphic hydrothermal fluids,but different from those of other fluid reservoirs.The Suoluogou gold deposit occurs in the altered intermediate basic volcanic rocks and the ore body is controlled by the brittle-ductile shear zone.According to the geological characteristics,combined with the analysis of fluid inclusions and C-H-O isotopes,it is considered that the Suoluogou is a typical orogenic gold deposit.

关 键 词：造山型金矿床 流体包裹体 H-O同位素 C-O同位素 甘孜-理塘缝合带 木里梭罗沟 

分 类 号：P581[天文地球—岩石学]