Scientific publications

The earliest Late Archaean variety of kyanite rocks of the Chupa suite of the Belomorides was produced by allochemical alteration of relict garnet-biotite plagiogneisses. New information on the origin of kyanite gneisses was obtained by analysing their structural and textural characteristics. Analysis was made by identifying the structural elements of shearing and by solving an inverse tectonophysical problem by selecting an adequate model paragenesis. It has been found that the formation of the mineral paragenesis of kyanite gneiss, which corresponds to kyanite-biotite-orthoclase metamorphic facies, was controlled by the structural elements of numerous shear parageneses that arise upon release of deviatoric stresses. The “background” thermodynamic parameters of deformed rocks did not reach the level which is critical for the mineral association of garnet-biotite gneiss formed at much lower temperature and pressure. Considering the role and distinctive pattern of deformation processes in the genesis of kyanite gneiss, its origin is assumed to be associated with stressmetamorphism.