Le LPS va co-organiser une session spéciale au prochain meeting de l'AGU (American Geophysical Union)du 5 au 9 décembre 2005 à San Francisco, USA, sur le thème des caractérisations in situ à hautes pressions et températures. En voici le descriptif :
Understanding physical and geochemical processes occurring in the Earth’s mantle and crust is one of the fundamental tasks of experimental research in the Earth Sciences community. Experimental approaches able to create confining conditions of the deep Earth are required allowing then measurement of relevant parameters. Usually investigations are performed “ex situ” in autoclaves, piston cylinders, etc. at pressure and temperature conditions corresponding to the studied process. The resulting phase assemblages and micro-fabrics are characterized “post mortem” at ambient conditions. On the other hand and from “in situ” observations, it is well known that a wide range of phases and micro fabrics dramatically change due to quenching. Additionally parameters like electrical conductivity, sound wave velocity, heat conductivity etc. can only be reached by “in situ” experiments. Real time observation of processes can be achieved: dissolution, chemical exchanges between phases, bubble growth, crystal growth and others. Therefore development of new high pressure apparatuses coupled with characterization techniques becomes one of the major tasks in experimental geosciences. Therefore, this session will focus on in situ characterizations of materials at high pressure and temperature in the field of geosciences and new related techniques. Indeed, continuous progresses devoted since the past decades to provide powerful experimental tools (diamond anvil cells, multi anvil press) and to improve micro-analytical techniques (synchrotron radiation techniques, Raman or Infrared spectroscopy) make accessible in situ studies of geological materials under extreme conditions. Our aim is to review this promising new methodology and the different approaches and to contribute to the progress of this whole new way of investigating geosciences.
Conveners : Hélène Bureau, LPS; Michael Burchard, Ruhr-Uni Bochum.
Date limite d'envoi électronique des résumés : 8 septembre 2005