Flow perturbations: a tool to study and characterize heterogeneous deformation

The classification of the myriad of small-scale structures that are used in tectonic analysis is presently based on their geometry, which makes it difficult to discover transitions and groups amongst them. An alternative would be to classify structures according to the flow type by which they form, but this is difficult. Although most structures form by heterogeneous flow, modelling studies are often focussed on bulk homogeneous flow, since the mathematical treatment of heterogeneous flow is cumbersome. Also, heterogeneous deformation patterns seem to occur in as many types as there are small-scale structures. This paper introduces the use of the geometry of flow perturbations to improve ou…