Sphalerite and pyrrhotite geothermometry of the new calumet sulphide deposit.

Abstract

Pyrrhotite and sphalerite deposition temperatures were determined in the ores of New Calumet Mine, Quebec. Forty-five pyrrhotite and fifty-two sphalerite determinations were made taken from various samples. Out of these, both geothermometers were used in 18 specimens. In most cases both values were reasonably close. Only four specimens showed greater difference for the two geothermometers than 56°C, the mean difference being 17°C. The temperature values for pyrrhotite range from 350° to 484°C, of that of sphalerite from 370° to 538°C. Using these values, isotherms were drawn throughout the orebodies based on the sphalerite data. The pyrrhotite values did not show any apparent systematic variation. The sphalerite isotherms coincide with the down-dip trend of the principal ore zones. No significant change in deposition temperatures is shown with depth. The thermal gradients are steepest laterally. "Hot spots" in the major ore zones may indicate channel-ways through which mineralizing solutions travelled