Conférence de Harry W. Green
I entered this field in the last stage, using microstructures + high-pressure experiments to understand these exciting rocks. Our first studies evoked great controversy ; I will use this controversy to demonstrate the power of microstructures in combination with HP experiments to sort out new and complicated discoveries in Geology. I’ll then show a pelitic gneiss that has made the full circle to 350+ km and back. More recently, a discovery of coesite-after-stishovite and TiO2 II in ophiolites provides a new window into the deep upwelling mantle. Lastly, I’ll show some inclusions from diamonds that are from the mantle transition zone and from deep in the lower mantle.
Thus, the geological record exposed at the surface is now known to contain scattered bits of rock that provide information on depths to greater than 300 km in both downwelling and upwelling arms of mantle convection. Lower mantle diamonds both extend this record by many hundreds of km and raise the question of how such diamonds were incorporated into kimberlites and brought to the surface.
Le professeur Harry W. Green dirige l'Institut de géophysique et de physique planétaire, il est également directeur du département des sciences de la terre à l'université de Californie, Riverside. USA.Cliquer ICI pour fermer
Dernière mise à jour : 08/01/2013