Sebastian Wolf

From small and cold to large and hot orogens: How do they grow and what are the influences of extensional inheritance and surface processes?

Authors: Sebastian G. Wolf, Ritske S. Huismans, Peter van der Beek

In this geolunch I will show you our recent work on mountain building, where we have been using numerical models to understand the archetypical evolution of an orogen on Earth.

During recent years, geodynamic models have underpinned our understanding of the growth of a mountain belt from a small, cold to a large, hot orogen as a function of the amount of convergence. Additionally, studies have demonstrated that the structural style of a mountain belt is strongly influenced by inherited weak (extensional) structures, the amount of erosion and deposition, as well as the distribution of shallow detachment horizons. We use upper-mantle scale plane-strain thermo-mechanical models coupled to a 2D, mass conserving surface process model (FastScape), to investigate the long-term evolution of mountain belts and the influence of extensional inheritance and surface processes thereon.

With our models we can establish an evolutionary framework for orogenic growth from a monovergent wedge to an orogenic plateau, and find that internal crustal loading is the main driver for the evolution. Extensional inheritance and simple surface processes modify the structures, but have no first order mechanical influence.