Modern stresses in the northern part of the Baltic Shield according to the data of the Pechenga geoblock studies and the section of the Kola super-deep well
© F.F. Gorbatsevich, S.N. Savchenko
Modern stresses of the northern Baltic Shield and Pechenga geoblock are governed by a separation of continental plates in the area of mid-oceanic rift zones of the Atlantic and Arctic Oceans and by pressure of the African plate on the Eurasian lithospheric plate. It was established that horizontal tectonic stresses along the Kola Superdeep Borehole vary from 7 MPa near the surface to 125 MPa at a depth of 11,5 km. The average ratio of the acting horizontal stresses (including the value of the lateral pressure that originated under the vertical component and the tectonic component) to the vertical ones is 0,7-0,8. Drastic changes in the horizontal component of the stresses in depth are caused by structural heterogeneities and elastic anisotropy of rocks.