Numerical Modeling of the Formation and Evolution of Rifted Continental Margins

Abstract

AbstractOn the basis of the isoviscous corner flow model, we establish an upwelling divergent mantle flow field which acts on the base of the continental lithosphere. This model can explain the deformation and thinning of the continental lithosphere leading to breakup and the initiation of sea‐floor spreading. The numerical modeling results indicate that the lithosphere experiences depth‐dependent stretch which depends on varied factors at different depths, and the surface heat flow significantly increases in response to an upwelling divergent mantle flow. The isostatic adjustment due to the mantle flow‐induced thermal disturbance leads to surface subsidence; meanwhile the uplift of hot material reduces the rheological strength of the lithosphere, especially at the deformation center. The critical depth of brittle deformation reduces and the range of ductile deformation extends greatly. This deformation finally evolves into continental breakup, mantle exhumation, and the formation of sea‐floor spreading and the rifted continental margin under the everlasting effect of the upwelling divergent mantle flow.