Abstract:

Precambrian geodynamics focuses on kinetics mechanism of sedimentation, magmatic, metamorphic and deformation, mantle and lithosphere of the Earth during 4.560.543 Ga, being the eternal frontier and research focus of Earth Science. The presentday study shows that the early Precambrian tectonics is difficult to adopt the theory of plate tectonics to be interpreted reasonably; origin time of plate tectonics through the Earth history may vary at various positions, but the mainstream understanding is that the plate tectonics regime occurred during 2.72.1 Ga, and so is the North China Craton. The preplate regimes appearing before plate tectonics has been proposed, including many kinds of understanding: mantle plume, mantle overturn, gravitational tectonics, and platelets, of which the gravitational tectonics was considered at the stage of layering or stratification on the Earth in the Hadean, especially 4.544.45 Ga of the core formation and mantle magma ocean. So far, for the origin of oval structures of crustal levels, there are 8 original models: diapirism, middlelower crust flow, horizontal channel flow, polyphase fold superposition, deformation partitioning, crackingsag subduction, multilayer topdown rheological flow and batholith intrusionderived bucklingpartitioning, they all can appear under extension, compression and strike slipping backgrounds. No matter what both plate tectonics and preplate regimes, global tectonic process seems to be top down mechanism.

Key words: Precmabrian, geodynamics, oval structure, granitegreenstone terrane, preplate regime