Influence of inherited rifted margin architecture on continental collision dynamics

Abstract

Continental collision is a key process in lithospheric evolution, driving mountain building, crustalthickening, and supercontinent assembly. Within the Wilson cycle, collision marks the finalstage following rifting, ocean spreading, and subduction. Early rifting and rifted margindevelopment precede basement accretion and hard continental collision, leaving complexrecords that complicate tectonic interpretations. We present mantle-scale numerical modelssimulating rifting, post-rift thermal re-equilibration, convergence, subduction, and collision.Results show that a strong continental crust produces narrow rifted margins, while weak crustleads to margins with wider hyperextended domains. Subduction initiates beneath riftedcontinental margins due to inherited zones of reduced grain size. We assess the impact of syn-rift sediment rheology, erosion rates, and mantle serpentinization on non-magmatic riftedmargin evolution, subduction and collision. Our findings indicate that rift-inherited architectureprimarily controls basement accretion and collision style, more than surface processes orsediment rheology. Lithospheric shear zones with reduced grain size may serve as the locationof subduction initiation. Comparisons with natural examples such as the Alps, Pyrenees, andGreater Caucasus support a first-order interpretation of their structural and mechanicalevolution based on our models.