New views on the structure and rheology of the lithosphere

Differences in the structure, composition and rheology of the lithosphere between the oceans, young orogenic belts and the ancient Precambrian shields are responsible for the variations in tectonic history seen at the Earth's surface over geological time. The last few years has seen a number of developments in the understanding of the lithosphere, which have challenged previously accepted views, and opened up many new directions in research. A coherent picture is now emerging that reconciles observations from fields as diverse as seismology, gravity, heat flow, rock mechanics, metamorphic petrology and geochemistry. Furthermore, the insights, and agreement, that these widely differing disciplines offer on the same subject produce an overall view that is more robust than any obtained from one of those disciplines alone. As is often the case in Earth Sciences, some of these ideas are not new, and their origins can be found in earlier studies. But in the interests of a coherent narrative, this talk follows a roughly chronological account of their development, as they became relevant or interlinked in the context of the current overall debate about lithosphere structure, rheology and evolution. -------------------------------------------------------------------------------- Séminaires généraux de l'Institut de Physique du Globe de Paris --------------------------------------------------------------------------------