Precambrian Geodynamics: quest for the missing paradigm

In contrast to modern-day plate tectonics, geodynamics of the early Earth stands as an intriguing and controversial issue, and currently represents a fundamental barrier in furthering our understanding of how Earth evolved through time. This geodynamics presents a unique challenge, as currently there is no consensus upon a global paradigm concerning the mantle dynamics and lithosphere tectonics in the Precambrian. This challenge is mainly due to the severe objective restrictions of obtaining geological and/or geophysical observations constraining Earth’s surface and interior dynamics back in geological time. As a result, the importance of well-constrained geological and geophysical data, and thoroughly studied present-day terrestrial, geodynamic style, modern-style plate tectonics, is almost unavoidably exaggerated and “stretched” toward the Precambrian Earth. This “plate tectonics trap” can only be avoided by further calibrating our geological intuition on the basis of numerical geodynamic modeling that integrates available geological, geochemical, petrological, and geochronological records. Here, based on numerical models, I discuss several key aspects of the Precambrian geodynamics including development of the continental crust, growth of cratonic keels and modern subduction and plate tectonic initiation.

свернуть