The influence of pre-collisional rift linkage on mountain building – a 3D geodynamic modelling study

It is well documented that many mountain belts - such as the Pyrenees, European Alps, Greater Caucasus, or Atlas - form through inversion of pre-collisional extensional basins. Looking in plan-view at these mountain belts, we observe along-strike variations in topography, orientation, and deformation patterns. However, the relationship between these characteristics and the inherited extensional architecture remains poorly known. Here, we use the 3D thermo-mechanical geodynamic model pTatin3D coupled to the landscape evolution model FastScape to investigate how pre-collisional rift-linkage influences rift inversion and mountain belt evolution. Presenting numerical models and a work minimization analysis, we show that rift basin offset and pre-existing weaknesses determine mountain belt evolution, which can be divided into a juvenile and mature stage. In the juvenile stage, extensional structures are reactivated, creating an orogen that resembles the rift structure. During the mature stage, the evolution depends on the subduction polarity, which is controlled by basin offset and existing structural weaknesses. Same polarity subduction retains the inherited basin configuration and creates an orogen with continuous high topography. Opposite polarity subduction overprints the pre-existing rift configuration and creates a discontinuous mountain belt with a characteristic topographic low in the transition zone. Comparison with the Greater Caucasus, Atlas, and Pyrenees suggests that the Greater Caucasus is a mature same-polarity orogen, the Atlas is a juvenile inversion orogen where subduction polarity plays no significant role, and the Pyrenees are a mature same-polarity orogen in which lateral variabilty is overprinted by differences in the amount of crustal shortening. Based on our results, we propose a simple diagnostic framework that establishes a direct link between topography and deep lithospheric structures, showing how extensional inheritance influences mountain building on Earth.

Associated article:
Wolf, S.G., Huismans, R.S., Muñoz, J.A., May, D.A. (2026) Rift linkage and inheritance determine collisional mountain belt evolution. Nature Communications 17, 84. https://doi.org/10.1038/s41467-025-66695-8