Rayleigh-Taylor model of the thermal instability in the visinity of the melt - solid density crossover: Numerical estimates and comparisons with observations
© Khazan Y.M.
A dispersion equation for a Rayleigh-Taylor model of thermal instability of a partially molten layer in the vicinity of the melt-solid density crossover is analyzed. It is shown that characteristic scales and times of the instability can be malched well with observed dimensions and ages of asthenolenses and the lower limit of distances between them. The required values of viscositiy do not contradict the laboratory measurements of rock reology under near solidus conditions. It is concluded that the asthenolenses are product of the thermal instability of the partuially moelten zone observed at 250-450 km depths beneath the Central Europe as the shear seismic wave low velocity zone.