Of The current research trends in tectonophysics, the study of deformation mechanisms and of relations quantifying their characteristic stress-strain-time behaviour (constitutive equations) should produce some of the most significant improvements in the interpretation of the structures and fabrics of deformed rocks. Such studies can shed light on phenomena as widely disparate in scale as the extent to which geologically significant flow occurs in the Earth's mantle, and the nature of preferred orientation in tectonites. They deal with phenomena that are of fundamental importance in attempts to model the structural evolution of the Earth's crust, either by computer studies or by scaled physical analogues of rock behaviour. In model studies the behaviour of real rock is assumed to follow a specific constitutive equation, i.e. a deformation mechanism is assumed. Yet many geologists are unfamiliar with the physics and chemistry of deformation processes, and even those researching these fields rarely have the time to take full advantage of the enormous quantities of pertinent literature produced by materials scientists.
Geologists and materials scientists both face similar problems in studying the phenomena of flow and fracture. Moreover, the increasing industrial concern with ceramics as new engineering materials means that scientists working in these two fields are interested in the deformation properties of often very similar materials. Meetings designed to promote an exchange of ideas can thus be of benefit to both disciplines. An important role of such meetings is to serve as the extent to which geologically significant flow occurs in the Earth's mantle,