科研之友
微信
新浪微博
Facebook
分享链接
摘要
<正>The Damoqujia gold deposit,discovered recently and located in the north of Zhaoping fault zone,is a large altered rock type deposit.In this paper,we report the preliminary research results of the fluid inclusions and discuss its metallogenic implications. The homogenization temperatures of fluid inclusions fall into four ranges:310～350℃,230～270℃,160～200℃and 110～150℃; corresponding to the four stages of hydrothermal ore-forming processes:coarse grain pyrite-milk white quartz stage（Ⅰ）,smoky gray Au-bearing quartz-fine grain pyrite stage（Ⅱ）,Au-bearing polymetallic sulfide-quartz stage（Ⅲ）,and quartz-carbonate stage（Ⅳ）. Ore-forming fluid is with low salinity and low density,ranging from 1.4 WtNaCl% to 13.6 WtNaCl% and from 0.48g/cm3 to 1.03g/cm3 respectively.The inclusions are dominated by H2O and CO2 in gaseous compositions,and Na+ and K+ in positive ions,SO42-and Cl- in negative ions of liquid compositions.Au-S complex is the major form for transportation of gold.The pressure varied from 260MPa to 340MPa during the formation of CO2-bearing inclusions at the early mineralization;the fluids are rich in SO42-and Na+.The pressure is 26-49×105 Pa during the formation of the aqueous salt inclusions in late mineralization,the inclusions are rich in CI-（F-）, Na+.δ18Oqurrtzis 10.64～12.68%o,and the correspondingδ18OH2O andδD is-5.44～6.47‰and-95.52～-106.48‰respectively.Based on the studies about compositions and hydrogen and oxygen isotopes of inclusions,it is evidenced that ore-forming fluid is magmatic hydrothermal fluid in early period,but affected by meteoric water in late.
-
单位地质过程与矿产资源国家重点实验室
