Time for anisotropy: The significance of mechanical anisotropy for the development of deformation structures

The forty-year history of the Journal of Structural Geology has recorded an enormous increase in the description, interpretation and modelling of deformation structures. Amongst factors that control deformation and the resulting structures, mechanical anisotropy has proven difficult to tackle. Using a Fast Fourier Transform-based numerical solver for viscoplastic deformation of crystalline materials, we illustrate how mechanical anisotropy has a profound effect on developing structures, such as crenulation cleavages, porphyroclast geometry and the initiation of shear bands and shear zones

A review of numerical modelling of the dynamics of microstructural development in rocks and ice: Past, present and future

This review provides an overview of the emergence and current status of numerical modelling of microstructures, a powerful tool for predicting the dynamic behaviour of rocks and ice at the microscale with consequence for the evolution of these materials at a larger scale. We emphasize the general philosophy behind such numerical models and their application to important geological phenomena such as dynamic recrystallization and strain localization. We focus in particular on the dynamics that emerge when multiple processes, which may either be enhancing or competing with each other, are simultaneously active. Here, the ability to track the evolving microstructure is a particular advantage of numerical modelling. We highlight advances through time and provide glimpses into future opportunities and challenges

Geological objects and physical parameter fields in the subsurface: a review

International audienceGeologists and geophysicists often approach the study of the Earth using different and complementary perspectives. To simplify, geologists like to define and study objects and make hypotheses about their origin, whereas geo-physicists often see the earth as a large, mostly unknown multivariate parameter field controlling complex physical processes. This paper discusses about some strategies to combine both approaches. In particular, I review some practical and theoretical frameworks associating petrophysical heterogeneities to the geometry and the history of geological objects. These frameworks open interesting perspectives to define prior parameter space in geophysical inverse problems, which can be consequential in under-constrained cases