A GEODYNAMIC MODEL FOR THE KARELIAN GRANITE-GREENSTONE REGION

Successively formed granite series are distinguished in the Karelian granite-greenstone region; they are synchronous with the linked greenstone belts or somewhat later than them. These series are similar to homologous Phanerozoic ones that act as indicators of island-arc, collisional, and postcollisional settings. The greenstone-belt volcanites are similar to those in island-arc and marginal basins, so the region can be considered as an ancient island-arc system. A model is proposed for formation in subduction and collision stages.