Abstract:

This paper summarizes different views and their corresponding evidence of the starting time of plate tectonics, and explores three requirements of starting plate tectonic system: rigid plate, subduction and mantle convection, and then further discusses the differences between the Precambrian subduction or plate tectonics regime and modernstyle subduction or plate tectonics regime. The three requirements of starting plate tectonic system met at the same time until during 2.72.1 Ga in different places around the world. But the modernstyle plate tectonic system and regime have a starting time of between 1.0 (or 1.9) to 0.8 (or 0.6) Ga; the remarked material records or identification markers are still ophiolite suites, HPUHP metamorphic rocks, and arc magmatic rocks. At last, we describe possible starting mechanisms and processes of plate tectonics to provide a constraint for understanding the differences of preplate tectonics and plate tectonics, and to provide some latest insights for promoting thoughts and explorations of a unified theory of geodynamics as well.

Key words: Precambrian, origin of rigid lithosphere, origin of subduction, origin of mantle circulation, origin of plate tectonics regime