Fig. 2: Phase equilibrium, quartz inclusion pressure and elastic barometry.
From: Lower crustal earthquake associated with highly pressurized frictional melts
a, Phase diagram of the pseudotachylyte matrix (Fig. 3a). Garnet is removed from bulk composition. The isopleths show the equilibrium composition of omphacite (Jd for jadeite between 30% and 45%) and plagioclase (Ab for albite between 75% and 85%). Coe is for coesite. b, Residual pressure in quartz inclusions calculated on the basis of two Raman peaks (464 and 128 cm–1) (ref. 32). A systematic difference of 0.1 GPa is observed. The mean error of the Raman shift is ~0.2 cm–1. The mean error for the residual pressures is shown by the error bar. Mean and maximum values are given in GPa. A pressurized quartz inclusion is shown in the inset. c, Elastic barometry based on the measured residual pressure (range given by the mean to maximum values). The temperature estimate (purple band) is based on the omphacite–garnet thermometer36. A 1D thermal diffusion model is used to calculate the cooling rate (top x-axis) of a 1-cm-thick melt vein with initial melt temperature of 1,500 °C and a wall-rock temperature of 700 °C. For details, see Methods.
