Scientific publications

The paper deals with the composition, structure and physical and mechanical properties of some Karelian granitoids of various genetic types that occur in the Svecofennian mobile belt and the Karelian geoblock and their building stone potential. The average density of granitoids was found to depend on the composition and percentage of feldspars and the presence of dark-coloured minerals. The authors show that, together with the mineral composition, size and shape of grains of basic rock-forming minerals, another essential factor that affects the strength and practical use of granitoids is the microdisturbance of rock. Considering that the microfracturing of igneous rocks can be characterized by water absorption in the samples analysed, the authors assume that the low values of anisotropy parameters, obtained for rapakivi granites of the 4th intrusive phase of the Salmi massif, suggest, together with high water absorption values, that the orientation of microfractures in the samples is chaotic rather than ordered. Rapakivi granite samples of intrusive phase I of the Salmi massif have fairly high water absorption values and distinct anisotropy, suggesting that the microfractures in this rock have an ordered orientation.