Proton-microprobe analysis of trace elements in sulfides from some massive-sulfide deposits.

Concentrations of Ge, As, Se, Ag, Cd, In, Sn and Sb in base metal sulphides were determined by the proton microprobe (Micro-PIXE) technique. The analyses (down to 7-20 ppm) were corroborated for concentrations above approx 200-300 ppm by electron microprobe. Solid solution of Ag in chalcopyrite, sphalerite and galena was confirmed. Solid solution of Ag in pyrite and pyrrhotite was problematical, as was solid solution of Sn in chalcopyrite. A combination of the electron microprobe and Micro-PIXE methods should be particularly useful in determining trace-element distributions in sulphides.-L.T.T.