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Session description:

At shallow depths, discrete faults dominate deformation and stress distribution within the Earth’s crust. Such brittle faults are potentially active over millions of years and influence the structural evolution at local and regional scale. Despite the importance of different physical processes during brittle failure (e.g. hydromechanical, chemical etc.), an accurate description of long-term physical processes during deformation along faults governing their mechanical behavior is still lacking. In geodynamic models of crustal deformation, these processes are commonly parameterized using weakening/hardening laws depending on strain, strain rate, or velocity descriptions, but often lack a physical basis.

The need of a certain amount of brittle weakening has been highlighted by several publications, as for example weakening of brittle faults in the crust might trigger deeper ductile deformation and thus control the formation of lithospheric-scale shear zones. Furthermore, brittle fault rheology, and therefore the potential of stress dispersion along such fault zones, has an immense influence on the mechanical and structural evolution of mountain belts, i.e. crustal fault pattern or localized crustal uplift.

In this session we invite contributions that address the mechanical evolution of brittle faults from the surface to the brittle-ductile transition. We aim to bring together experimental, numerical or field studies to promote our understanding of the processes governing brittle fault mechanics. Studies that cross the lines between the different methods are particularly welcome.

Marcel Thielmann
Postdoc