Rheology and geodynamic modelling: the next step forward

The application of continuum mechanics and microstructural analysis to geol ogical studies over the past 30 years has spurred earth scientists to reass ess fundamental tectonic processes such as subduction, collision and riftin g in terms of dynamics. Armed with new analytical methods, geologists have returned to the field to look at rock structures with more mechanistic eyes . The advent of sophisticated computers, programs, and laboratory deformati on equipment has facilitated the simulation of geodynamic processes that ra nge in scale from the grain to the lithosphere. The result has been special ization, with the concomitant opening of communication gaps between geodyna micists, field geologists and rock mechanicists. Partly, these gaps reflect differences of perception and approach. In order to bridge these gaps, a w orkshop was organized after the DRM conference to debate how field and labo ratory studies of deformed rocks can improve our understanding of lithosphe ric theology, and in turn, how this understanding can be used to refine dyn amic models of orogenesis. The workshop hosted participants with background s in structural geology, experimental rock mechanics, metamorphic petrology and both numerical and analogue modelling. This paper summarizes the main controversies and conclusions reached during the workshop. For the sake of brevity, referencing in this summary is restricted to literature referred t o during the oral presentations and to comments made by speakers themselves (names italicized).