Comparison of petrophysical characteristics of prenite-pumpellyite and amphibolite metamorphic facies (Kola peninsula)

Petrophysical properties of the metavolcanites from the Matert Fm of the Pechenga palaeorift structure and the massif rocks of western Lake Chudzyavr have been studied. Metavolcanites of the Pechenga structure are metamorphosed at prehnite-pumpellyite and massif rocks of Lake Chudzyavr - at amphibolite facies. An assessment of the rock elastic anisotropy by the acoustopolariscopy method has been made, the densities, compression and shear wave velocities et al. have been determined in lab conditions. The simulation of density, velocity characteristics of the rocks has been carried out in order to assess their deep properties. According to the laboratory studies, the samples of prehnite-pumpellyite facies show greater densities, compression and shear wave velocities than those of amphibolite facies. It was shown that the model (calculated) densities, velocity characteristics of the massif rocks from Lake Chudzyavr were much greater than the experimental data. A comparison of the acoustopolarigrams shows that using the acoustopolariscopy method one can visually distinguish rocks of prehnite- pumpellyite facies from those of amphibolite facies of metamorphism.