Geophysical research: article

Аnnotation: The model of structure and formation of a magnetically active layer of the White Sea paleorift system was created based on the results of analysis and interpretation of anomalous magnetic field and other geological and geophysical data. It is shown that the structure of this layer is complex and reflects all main stages of tectonic activity of the region from the middle and late Riphean to events of the last ice age in a Pleistocene. The model of the magnetically active layer is composed from three structural levels (horizons); each level reflects a certain stage of formation of the studied area. The lower structural level in the basis of a magnetically active layer reflects a rift stage of evolution of the White Sea mobile belt in the middle and a late Riphean characterized by manifestation of a continental riftogenez [Baluyev et al., 2012]. The average structural horizon reflects the middle Paleozoic, late Devonian, stage of the rift system reactivation characterized by alkaline and ultramafic magmatism and presented by swarms of alkaline dikes and tubes of explosion including kimberlites. The upper structural level reflects a high-frequency component of anomalous magnetic field and is connected with the sources of high magnetic anomalies located at its top. Characteristics of this structural level suggest that it could be formed during the last late stage of tectonic activation of this region.