Model block regions: approximation schemes of the Earth’s crust block structure in the northeastern part of the Baltic Shield for the period of 3.0–1.6 Ga (from Filatova 2014). (a) 3.0–2.8 Ga; (b) 2.8–2.5 Ga; (c) 2.5–1.6 Ga; (1) contours of the modern coastline; (2) contours of the study region; T is force