Archean crust-mantle geodynamic regimes: A review

Abstract

The crust-mantle dynamic system of the formation and evolution of the early Earth crust is a frontier field in current Earth Science. This paper mainly introduces the popular dynamic models, comprising the stagnant-lid, mantle plume, sagduction, dripping, hot plate subduction and flat plate subduction models. Geological signatures and thermomechanical experiments suggest that the above-mentioned first four dynamic models most likely occurred in the early Archean under high mantle potential temperature and high thermal state conditions although they may have survived in small scales to the late Archean, while the hot- and flat-plate subductions chiefly operated during the late Archean as the mantle potential temperature decreasing although they could have started since the Paleoarchean. The late Mesoarchean is a crucial transition period of the crust-mantle dynamic regimes, the diversified geodynamic regimes can coexist, for example, mantle plume and hot plate subduction, and pre-subduction buckling, sagduction and dripping mechanism. These regimes possibly emerged alternately, affected each other or operated in combination. Therefore, we believe that the Archean geodynamic regime has obvious variations as the mantle potential temperature decreasing from early to late Archean, of which the transition may be an interrelated and gradual evolved process rather than a sudden event.