Relationship of Heterogeneously Reworked Basement Blocks of the Southwestern Foreland of the Lapland-Kola Orogen (Belomorian Province of the Fennoscandian Shield)

The relationship between the Gridinsky and Kirbeysky blocks was studied using geological-structural mapping in the eastern Belomorian Province of the Fennoscandian Shield. The blocks were reworked differently during the Lapland-Kola collision. In the Gridinsky block, intrusive contacts of Early Paleoproterozoic metagabbroid dikes with an Archean host rocks structure are preserved. In the Kirbeysky Block, the Early Paleoproterozoic metagabbroids were tectonically reworked along with Archean host rocks during ductile deformations. The boundary between blocks is a thick zone of mylonitization interpreted as a thrust-nappe structure.