An experimental study of the replacement of halogens in apatite hydrothermal reactions at 350—450℃

Abstract

Apatite has characteristic properties that interact with the fluid through replacement reaction of a ternary solid solution and is used as a tracer of fluids in the rock. However, the mechanisms and time-scale of apatite replacement at crustal P-T conditions have not been well constrained. In this study, F-Ap was tried to be replaced by Cl-Ap under crustal condition to elucidate the time scales of fluid-rock reaction. Thermodynamic calculation of the reaction suggested that the replacement reaction is largely involved in the fluid/rock ratio and the pH of the solution.