EXPERIMENTAL STUDIES OF THE MELTING PROCESSES IN A PYRRHOTINE-WATER SYSTEM

A series of tests were performed on pyrrhotine melting in the presence of H2O at P-tot,,similar to P-fl = 1 kbar and T = 1000-1160 degrees C . The amount of water in the system varied from 5 to 41 wt %, and the fugacity of O-2 during the experiments was controlled by a NNO-buffer. According to the data, the temperature of a pyrrhotine solidus decrea ses only in a water concentration range of 0 to 10 wt %. At higher wat er concentrations, the temperature of a pyrrhotine solidus drops const antly by more than 80-90 degrees C with respect to the temperature of a pyrrhotine ''dry'' solidus. The experimental results disagree with t he theoretical calculations performed by EG. Smith on the influence of water on the temperature of pyrrhotine melting.