Equilibration temperatures in enstatite chondrites

Equilibration temperatures for enstatite chondrites are calculated using a method suggested by Larimer (1968). The temperatures range from 640° to 840°C. The method yields temperatures which, in principle, are correct on a relative scale but the absolute error may be a large as 150°. There is a good correlation between the calculated temperatures and petrologic type as well as other mineralogic characteristics and bulk composition. Partial pressures of sulfur and oxygen at the time of equilibration were: pS₂ ~ 10^?8?10^?12 atm and pO₂ ~ 10^?28?10^?37.