EID-02 Properties and dynamics of mantle and core Eiji Ohtani, Gerd Steinle-Neumann, Bernhard Steinberger, James Conolly (IMA-CMP)

This session covers mineralogy, and geochemistry of the mantle and core and its applications to dynamics of the interior of the Earth. This session includes new experimental and theoretical studies on the mantle and core; i.e., phase transformations in the mantle such as post-spinel, post-garnet, and post-perovskite transformations, and spin-transitions in the lower mantle, elastic and rheological properties of the mantle and core materials, processes at the core-mantle boundary, and metal-silicate partitioning and its applications to the core formation processes. We encourage contributions not only from high pressure mineral physics, but also from many related fields such as geochemistry and geodynamics of the mantle and core. This session is sponsored by Commission of Physics of Minerals, IMA.


EID-03 Deep Earth seismic tomography: Observations, models and interpretations Frédéric Deschamps, Lapo Boschi, Wim Spakman

Seismic tomography is, so far, our most powerful tool to infer the deep mantle 3D-structure. Agreements have recently been reached on important questions, including the long-wavelength structure of shear-wave velocity anomalies and the existence of deep slabs. Other problems are still debated, in particular the origin of hotspots, the nature and structure of the D” layer, and the access to independent constraints on the density. Related challenges concern the mapping of small-scale structures and the estimate of model uncertainties. Beyond the mapping of seismic velocity anomalies, the goal of seismic tomography is to provide appropriate descriptions of deep Earth thermo-chemical structure, and integrate them in a consistent geodynamical model. This can be achieved through multidisciplinary approaches that link recent discoveries and advances in seismology, mineral physics, geochemistry and geodynamics. A long debated question is the origin of seismic velocity anomalies. Mounting evidences suggest that a purely thermal origin is inappropriate to fully explain the observed anomalies. Chemical variations are likely present, but their inference remains a difficult task that requires careful modeling. The present symposium aims to address all these questions. We welcome all contributions that provide new views, ideas and results on these problems and related topics.


EID-04 Mantle mineralogy and rheology Shun-ichiro Karato, Ian Jackson

The physical and chemical properties of minerals and their aggregates have an important control on the evolution and dynamics of Earth and other terrestrial planets. During the last several years, there has been major progress in both experimental and theoretical studies on the properties minerals. Progress in experimental studies is mainly based on the development of new techniques particularly at high pressures and temperatures, and the main theoretical development has been through the analysis of thermodynamics of defects in addition to some contributions from “first-principles” calculations. The strong influence of pressure and fugacity of water on some of the transport properties has been documented. We invite presentations of new results or reviews on all aspects of mantle mineralogy and rheology with particular emphasis on transport properties including plastic deformation (large-strain deformation and small strain anelastic deformation), and electrical and thermal conductivity. 


EID-05 Mantle petrology M. Coltorti, M. Wilson, M. Gregoire, S. Arai

Although the mantle occupies more than 75% of the volume of the Earth, its composition, the processes which occur within it and its evolution with time remain matters of considerable debate. We seek contributions from people studying mantle xenoliths or larger mantle fragments such as alpine and abyssal peridotites and ophiolites, which allow the direct study of mantle materials at various scales, as well as those using an inverse approach based on primitive magma compositions to constrain the chemical characteristics of their mantle source. The main topics include: (1) The evolution of mantle through time - including definition of the "starting" composition from which depletion and/or enrichment/refertilization processes can be identified; (2)The mineralogical and geochemical signatures of fluids/melts migrating through the mantle in both anorogenic and orogenic (subduction-related) settings; (3) The role of crustal recycling and metasomatism in the geochemical evolution of the mantle and their relationship to mantle "endmembers"; (4) The role of mantle plumes and mantle convection in producing/homogenising geochemical heterogeneities.


EID-07 Geophysical evidence for mantle heterogeneity R. van der Hilst, A. Levander, H. Thybo

Significant mantle heterogeneity has been documented on all scale lengths, primarily by application of seismological methods, but also in exposures of upper mantle rocks. Recent studies provide new insight into the origin of the heterogenity by use of a variety of methods. Seismic tomography very early demonstrated significant long wavelength heterogenity, which has been interpreted successfully in terms of subduction and plume structure. In places controlled source seismological methods have further increased the resolution of heterogeneity in the upper mantle, and recently receiver function and other direct imaging techniques have proven promising for improvements in resolution. High resolution teleseismic migration methods have shown that certain depth intervals may be very heterogeneous, in particular the lithosphere and the D’’ region at the base of the mantle. There is considerable debate on the origin of the mantle heterogeneity in terms of chemical-mineralogical variations and physical properties. We invite contributions on documentation and interpretation of mantle heterogeneity at any scale length, from outcrop to global, and particularly encourage contributions that relate seismic velocity to thermal state or chemical/mineralogical.


EID-08 Geodynamic implications of mantle heterogeneity George Helffrich, Louise Kellogg, Paul Tackley

Heterogeneity in the mantle's chemistry is well-established from the observed variations in the many isotopic systems of mantle rocks. Geologists also recognize the great differences in the structure and composition of continental rocks in contrast to those from the oceans. More recently, seismologists found evidence for heterogeneity in the mantle on scales as large as hemispheric and as small as a kilometer at shallow levels (the mantle lithosphere) and deep (the top, middle and bottom of the lower mantle). Differentiation processes link these different heterogeneity types because they change the composition, mineralogy and texture of rocks. What are the geodynamic implications of the mantle's heterogeneity? In this symposium we focus on the processes that create, change and destroy heterogeneity in the mantle and how they shape the mantle's evolution. We invite observers and modellers of heterogeneity to explore what it tells us about physical processes that embed heterogeneity in the rocks we sample or we detect at depth in the mantle.


EID-09 The dynamics of plumes Ulrich Achauer, Bernhard Steinberger

This symposium intends to bring together scientists in the field of mantle plumes research to discuss the state-of-the-art of mantle plume dynamics and their geodynamic evolution. Over the last decade seismic tomographic models as well as the geodynamic modelling techniques have greatly improved with the resolution of the models getting better and better with increasing computer power and available data. While the new models give more realistic pictures of what plumes may look like, the question as to the origin and evolution of mantle plumes is still highly debated. Among the important questions and topics, we would like to emphasize the following: recent advances in the tomographic imaging of various mantle regions; mapping of thermo-chemical lateral anomalies, and the dynamics of thermo-chemical plumes; relation between mantle plumes and features in the lowermost mantle. Especially welcome are interdisciplinary presentations from the fields such as seismology, geochemistry, high pressure mineral physics and geodynamic modelling, which will make use of different data sources to come to better constrained models of mantle plumes.


EID-10 Phase transformations in the Earth's interior Bernard J. Wood, Craig R. Bina  Invited speakers: Tetsuo Irifune, Mike Kendall, Sang-Heon Shim, Lars Stixrude, Suzan van der Lee 

From hydration-dehydration reactions in subduction zones to subsolidus polymorphism and disproportionation in the transition zone, from electronic-spin transitions in the lower mantle to polymorphism and melting relations near the core-mantle boundary, phase transformations play a major role in the Earth's interior. We encourage contributions on the analysis of phase transformations by experiment, theory, and simulation, as well as studies of their geophysical signatures and geodynamical consequences.