Lithospheric Structure of the Kola Region from Seismological Data

The article presents the results of a study of the crust and upper mantle velocity structure in the central and Arctic parts of the Kola region from the receiver function and surface wave tomography. Significant heterogeneity of the upper mantle was revealed. An increase in the thickness of the crust from north to south is shown, from values of about 33 km in the Murmansk block to 40 km in the Belomorian block. Within the Kola and Belomorian blocks, a layer of lower shear wave velocities was identified at depths of about 90–140 km, probably, marking the mid-lithospheric discontinuity (MLD). This layer has not been identified in the Murmansk block. The obtained two-dimensional maps of the distribution of shear wave velocities at depths up to 500 km do not reveal the sublatitudinal zoning traced in the tectonic structure of the Kola region.