Fluid inclusions in fluorite from the Appalachian Mississippi Valley-type fluorite-barite deposits of the Sweetwater district in east Tennessee indicate that the mineralizing solutions were sodium-potassium-chloride brines with an average temperature of 107 degrees C and an average salinity of about 16 equiv. wt percent NaCl. A strong negative correlation of homogenization and freezing temperatures, which was observed for inclusions from the southeast part of the district, was interpreted to indicate that two solutions were present during fluorite deposition in this area: a warm (160 degrees C), less saline (12%) solution and a cool (80 degrees C), more saline (30%) solution. A connate source is considered likely for both solutions and the warm, less saline solution appears to have come from at or beyond the east edge of the district. Mixing of these solutions could have caused ore deposition in the southeast belt, although cooling probably caused deposition elsewhere in the district. Published data suggest that two similarly distinct solutions were present in the nearby east Tennessee zinc district.