The effect of water,pressure, and strain on Al/Si order-disorder kinetics in feldspar

The disordering kinetics of Al/Si in albite depend on how the samples are dried, and thus on the presence of trace amounts of water. The disordering rate increases with water content and confining pressure. At 10 kb the activation energy is about 67 kcal/mole compared to about 87 kcal/mole for samples disordered in air. Simultaneous plastic deformation increases the disordering rate and the effect is most pronounced below 900° C at 10^?6/s. Some albite ordering and microcline disordering experiments show similar kinetic behavior. These results are significant for interpreting the structural state and the high-temperature deformation of feldspars.