The Onega and Michigan Basins: Comparative Geodynamics and the Origin of Negative Intraplatform Morphostructures

摘要

The structure and geodynamic evolution of two negative crustal morphostructures, the Onega basin (Baltic shield) and the Michigan basin (North American craton) are compared. These two morphostructures differ in the time of initial subsidence, sedimentation history, structure, and the nature of their igneous activity and metamorphic processes, but still have much in common and exhibit a number of similar characteristics. This suggests that their origin and evolution were guided by two categories of geodynamic regimes: superregional (global), controlling the common features of these basins, and regional, responsible for individual evolutionary features. Following some other researchers, the global regime is supposed to be related to the general deformation of the Earth's spheroid.