25th International Union of Geodesy and Geophysics (IUGG) General Assembly – Earth on the Edge: Science for a Sustainable Planet

Start Date: 
Tuesday, June 28, 2011
End Date: 
Thursday, July 7, 2011

Location: Melbourne Convention & Exhibition Centre, Melbourne, Australia

Web: http://www.iugg2011.com/

Includes the following sessions:

Symposium J-S05/J-V04: The Davies mantle: reconciling geophysical and geochemical perspectives

Convenors: Ian Jackson (ian.jackson@anu.edu.au), Ian Campbell (ian.campbell@anu.edu.au), Louis Moresi (louis.moresi@sci.monash.edu.au), Hans-Peter Bunge (bunge@lmu.de), Albrecht Hofmann (albrecht.hofmann@mpic.de)

This symposium, reflecting on the career-long contribution of Geoff Davies, is intended to provide an interdisciplinary forum for discussion of geophysical and geochemical constraints on mantle structure, chemical composition and dynamical processes. The separation of basaltic melt from refractory harzburgitic residue generates heterogeneity that is resistant to re-homogenization during subsequent mantle convection. Seismic tomography suggests that wavespeed heterogeneity is concentrated in the upper and lowermost parts of the mantle. Geochemical studies provide evidence of long-lived heterogeneity at various spatial scales. Numerical modelling of mantle convection favours at least episodic whole-mantle convection over the strictly layered alternative. Other topical issues include chemically equilibrated compositional models versus mechanical mixtures of components of contrasting chemical composition; melting of eclogite-pyroxenite lenses in a harzburgite mantle; the seismological observability of mantle plumes; the influence of pressure-induced electronic spin-pairing on wavespeed-depth gradients in the lower mantle; and the survival of heterogeneity in a vigorously convecting mantle.

Keynote speakers:

Rick Carlson (Carnegie Institution of Washington)
Cinzia Farnetani (Institut de Physique du Globe de Paris)

Invited speakers (confirmed so far - more to come):

Bill McDonough (University of Maryland)
Eiichi Takahashi (Tokyo Institute of Technology)
Shijie Zhong (University of Colorado)

Melbourne, Australia