The effect of iron content on the kinetics of talc dehydration and its geological significance

The effect of iron content on the kinetics of talc dehydration was studied with talc of different iron values using in-situ synchrotron X-ray diffraction (XRD).The sample particle size is 2~5μm.The air atmosphere synchrotron radiation in situ XRD de-hydration experiment was carried out under atmospheric pressure.High content of iron obviously resulted in lower dehydration tem-perature.The difference of the dehydration temperature of two samples was above 127℃.The dehydration of talc followed random nucleation and growth mechanism, and fitted Avrami equation, with n being 1.669.The results suggest that the dehydration of differ-ent iron values of talc may occur at the different depths around hundreds of kilometers, so the study was significant to the understand-ing of the genetic mechanism of earthquakes in the subduction zone.