| In this paper,the scientific issues surrounding Northeast Yunnan Pb-Zn ore district Fuller bed structure and mineralization coupling relationship,relying mentor borne by the National Natural Science Fund Project " metallogenic mechanism of lead-zinc germanium northeast Yunnan large pool of research and target preferred "carried topics,at the conclusion,based on the results of previous studies,combined with regional geological setting and geological characteristics of the deposit,focusing on the new monarch station on the 1st deposit ore body fluid inclusions in sphalerite petrography,mineral ores(sphalerite,galena and pyrite)component analysis and stable isotope geochemistry,investigate the source of the ore-forming fluids and minerals,geochemical evidence presented ore-forming fluid coupling structure and mineralization.Has made the following main understanding:(1)The deposit sphalerite different types including tan-red-brown sphalerite,yellow-brown sphalerite,light-colored sphalerite.Different types of ore through the 1st thrust folds on the disc distribution of fluid inclusions in sphalerite petrographic studies,the results show:fluid inclusions in sphalerite mainly oval-shaped,rod,negative crystal and irregular shape the primary inclusions.Sphalerite generations from morning till night,and its corresponding inclusion petrography is:tanred-brown sphalerite inclusions are mainly pure liquid inclusions,pure vapor inclusions rich liquid two-phase phase inclusions contain daughter minerals and multiphase inclusions composed;yellow-brown sphalerite inclusions are mainly composed of pure vapor inclusions,pure liquid inclusions,gas-liquid two-phase liquid-rich inclusions composed;colored sphalerite mineral inclusions mainly composed of pure vapor inclusions,pure liquid inclusions,gas-liquid two-phase liquid-rich inclusions composed;(2)different types of inclusions in sphalerite temperature test temperature,salinity,density,respectively:tan-red-brown sphalerite homogenization temperature of 164-196℃,the average 180℃ salinity 15.9-19.3wt%NaCleq,an average of 17.6 wt%NaCleq,the average density of 1.02g/cm3;yellow-brown sphalerite homogenization temperature of 90-180℃,the average 150℃,salinity 10.7-21.1 wt%NacCleq,an average of 16.7wt%NaCleq,the average density of 1.04g/cm3;colored sphalerite homogenization temperature of 106-180℃,the average 138℃,salinity 16.6-18.8wt%NaCleq,average 18wt%NaCleq,the average density to 1.054g/cm3;inclusion test data shows,reflecting the formation of sphalerite from morning till night,homogenization temperature was gradually decreased.Forming fluid is to H2O,CO2 as a main component moderate salinity,medium density Ca(Mg)-Na-Cl-SO4 type fluid.(3)electron microprobe,ICP-MS for the main ore minerals,trace elements for testing,combined with the corresponding geochemical diagrams(galena Pb-lnAg illustrations,lnSb-lnBi diagrams and sphalerite lnGa-lnIn diagrams,etc.)test data analysis,the results support the deposit is-Genesis " deposition transformation."(4)the composition of the ore minerals by sulfur isotope analysis,the data show:sphalerite δ34S values between 13.5～15.2‰,an average of 14.2‰,poor 1.7 ‰;δ34S values between galena 12.2～12.9‰ with an average of 12.55‰,poor 0.7‰;pyrite δ34S value of 14.4.By dolomite oxygen isotope composition analysis,the data show:δ13CV-PDB value between-0.3～4‰,average 2.7‰,poor 4.3‰;δ18OV-PDB values ranged between-13.7～-9.8‰ The average-12.2‰,poor 3.9‰;δ18OV-SMOW values ranged between 16.7～20.8‰,with an average 18.4‰,poor 4.1‰.Combined with previous data on the hydrogen isotopic composition:δD values between-76～-60‰,poor as 16‰,with an average of-64‰;δ18O value of 10.8～14.7‰,poor as 3.9‰,the average 12.6‰.Based on the above data analysis,from the formation of sulfur mineralization,ore-forming fluid from the construction of water and fluids from the dissolution of carbon in marine carbonate rocks.(5)integrated fluid geochemistry,trace element geochemistry and ore-forming conditions,discusses the structure-fluid coupling relationship,that the transformation is a strong genetic type of deposit type lead-zinc deposits. |
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