Rheology of the Lithosphere Across Scales: From Field Observations and Physical Experiments to Numerical Models

P. Io Ioannidi, University of Louisiana at Lafayette
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Abstract

Deformation of the lithosphere occurs across different scales, from micrometers to kilometers, and is largely dependent on the mechanical properties of the rocks that dominate at different depths, as well as the external conditions these rocks are subjected to. Field observations of deformed rocks and their structures provide the most direct insights into rock deformation: at shallow depths, frictional deformation is prominent; as depth increases, viscous deformation processes take over, with semi-frictional deformation occurring between the two endmembers.

One of the benefits of combining field observations with physical and numerical experiments is that we can benchmark rheologies used in numerical experiments based on material properties instead of mathematical equations. Here, I will present numerical experiments focused on the rheological behaviour of rocks across a variety of tectonic settings, such as frictional fault zones and semi-frictional and viscous subduction shear zones. I will focus on the information one can extract from exhumed rocks about the geodynamic evolution of rocks, on ways in which numerical tools help decipher deformation and rheology, as well as the spatio-temporal scales in which we see contrasting rock rheologies.

Session

Experiments of all sorts