%0 Article %J Nature Communications %D 2022 %T The role of gravitational body forces in the development of metamorphic core complexes %A Bahadori, Alireza %A Holt, William E. %A Austermann, Jacqueline %A Campbell, Lajhon %A Rasbury, E. Troy %A Davis, Daniel M. %A Calvelage, Christopher M. %A Flesch, Lucy M. %N 1 %P 5646 %U https://doi.org/10.1038/s41467-022-33361-2 %V 13 %8 Sep %1 10.1038/s41467-022-33361-2 %K ASPECT %X Within extreme continental extension areas, ductile middle crust is exhumed at the surface as metamorphic core complexes. Sophisticated quantitative models of extreme extension predicted upward transport of ductile middle-lower crust through time. Here we develop a general model for metamorphic core complexes formation and demonstrate that they result from theĀ collapse of a mountain belt supported by a thickened crustal root. We show that gravitational body forces generated by topography and crustal root cause an upward flow pattern of the ductile lower-middle crust, facilitated by a detachment surface evolving into low-angle normal fault. This detachment surface acquires large amounts of finite strain, consistent with thick mylonite zones found in metamorphic core complexes. Isostatic rebound exposes the detachment in a domed upwarp, while the final Moho discontinuity across the extended region relaxes to a flat geometry. This work suggests that belts of metamorphic core complexes are a fossil signature of collapsed highlands.