Evidence for the Mesozoic endogenous activity in the northeastern part of the Fennoscandian Shield

There are several stages of endogenous activity identified in the geological evolution of the northeast� ern part of Fennoscandia; the longest of them finished 1.8 Ga and then this part of the craton stabilized and had a pattern with the structural features close to the modern ones. The following long amagmatic period of more than 1.3 Ga finished in the Paleozoic by plume� lithospheric processes that formed the Kola alkaline province (0.40–0.36 Ga) and completed the develop� ment of riftogenic structures of the southeast White Sea region [7]. Later geological evidence that could signify the manifestation of endogenic activity in the period from 350 Ma until the present has not been found within northeastern part of the shield. Assessment of geodynamic environments existing at the Phanerozoic stage in the evolution of northeast Fennoscandia and reconstruction of motion trend for the Kola megablock in the Paleozoic are of great importance for determination of what the localization conditions of mantle melts produced the Kola alkaline province were. The paleomagnetic method can be involved in solution of this problem; however, the interval of 400–340 Ma BP is the most discussed in the Phanerozoic segment of the apparent polar wander path (APWP) for the East European Craton because of the nearly total absence of reliable paleomagnetic poles of the Devonian age. In order to obtain new data corresponding the modern criteria of reliability, we carried out reconnais� sance paleomagnetic studies of dolerite and alkaline lamprophyric dyke swarms, whose ages fall within the interval of 390–370 Ma according to the geochrono� logical datings (Rb–Sr, Sm–Nd