Abstract:

Maoping  tungsten deposit  is a  large W-Sn-polymetallic deposit discovered  recently  in southern Jiangxi Province.
It comprises  two  types of ore-bodies,  i.e. quartz-vein  type and greisenized-granite  type. This paper studies  the  fluid  inclusions
in quartz and  topaz occurring  in wolframite-quartz-veins, which mainly  includes microthermometry and Laser Raman analysis.
Besides,  the homogenization  temperatures of  fluid  inclusions  in wolframite were determined under an  infra-red microscope.
Results show  that  fluid  inclusions  in both quartz and  topaz are mainly  liquid-rich  two-phase aqueous solution  (H2O-NaCl),  in
addition  to small amount of CO2-bearing  three-phase aqueous solution  in quartz. The homogenization  temperatures  from quartz
show a wider range variations and can be divided into two main periods, indicating two stages of ore precipitation. The CO2-bearing
three-phase inclusions have homogenization temperatures similar to those of the higher temperature period of the above inclusions,
but  lower salinities and different homogenizing ways. Fluid  inclusions  in wolframite have highest homogenization  temperatures
and salinities, whereas those in topaz also show high homogenization temperatures and salinities, and narrow variation range. The
characteristics of homogenization temperatures and salinities from fluid inclusions in quartz reveal multiple-stages of ore-forming process and  the complexity of  fluid evolution.  It  is concluded  from  fluid  inclusions  that  the early-stage boiling and  late-stage
mixing are probably the major mechanism of formation of wolframite-quartz-vein type ore in the Maoping deposit

Key words: fluid inclusion, microthermometry, Raman spectra, Maoping tungsten deposit, southern Jiangxi