<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Dear Colleagues,<br><br>We would like to draw your attention to a special SEDI session <br>"DI08: Chemical Heterogeneities in the Earth's Mantle: Their Roles <br>in the Early Earth Differentiation, Mantle Dynamics and Geochemistry" <br>for the coming fall AGU meeting. This is a multi-disciplinary session. <br>We intend to have discussions from the upper mantle to the lower mantle, <br>from seismology, mineral physics, geodynamics, to geochemistry, and <br>from early-earth to present-day mantle heterogeneities. <br><br>We would appreciate your participation and very much look forward <br>to seeing you at AGU.<br><br>The deadline for submission of abstracts is September 10th.<br><br>Our apologies, if your receive this email multiple times. <br><br>Conveners: <br><br>Lianxing Wen<br>Stony Brook University<br>Dept. Geosciences<br>Stony Brook, NY, USA 11794<br>1-631-632-1726<br><a href="mailto:Lianxing.Wen@sunysb.edu">Lianxing.Wen@sunysb.edu</a> <br><br>Sang-Heon Shim<br>Massachusetts Institute of Technology<br>USA <br><a href="mailto:sangshim@mit.edu">sangshim@mit.edu</a><br><br>Trond Torsvik<br>Geological Survey Norway<br>Leiv Eirikssons Vei 39<br> PB 3006 Lade<br>Trondheim, NOR N-7002<br><a href="mailto:trond.torsvik@ngu.no">trond.torsvik@ngu.no</a><br><br>Takashi Nakagawa<br>Kyushu University<br>Earth & Planetary Sciences<br> 6-10-1, Hakozaki<br>Fukuoka, JPN 812-8581<br><a href="mailto:takashi@geo.kyushu-u.ac.jp">takashi@geo.kyushu-u.ac.jp</a><br><br>Michael Thorne<br>University of Utah<br>Dept. of Geology and Geophysics<br> 135 South 1460 East<br>Salt Lake City, UT, USA 84112<br>801-513-9351<br><a href="mailto:michael.thorne@utah.edu">michael.thorne@utah.edu</a><br><br><br>Jung-Fu Lin<br>University of Texas at Austin<br>USA <br><a href="mailto:afu@jsg.utexas.edu">afu@jsg.utexas.edu</a><br><br><br><br>--------------------------------------------------------------------------- <br>DI08: Chemical Heterogeneities in the Earth's Mantle: Their Roles in the Early Earth Differentiation, Mantle Dynamics and Geochemistry <br><br>Recent high-resolution seismic studies have suggested the existence of large-scale velocity anomalies in the Earth’s mantle. Until recently, most heterogeneities have been interpreted as variations in temperature and chemical composition (mainly Fe and Si). However, recent discoveries in seismology and mineral physics, such as, sharp edges and large velocity reductions of the seismic anomalies, the large hydrogen storage capacity of transition zone minerals, the spin transition of Fe in silicates and oxides in the mid-mantle, the perovskite to postperovskite transition in the lowermost mantle, and the possible presence of melt atop the transition zone and in the deep mantle, call for new interpretations of mantle heterogeneities. Furthermore, a broad range of exciting proposals has been recently made on the origin, formation and dynamical evolution of these anomalies, as well as possible roles they play in the early Earth differentiation, mantle thermo-chemical plume formation, and explaining relative hotspot motion and the geochemical observations at the Earth’s surface.<br><br>Therefore, it is timely to discuss seismic evidence and developments in understanding the occurrence, observational consequences, and inter-relationships of the various kinds of mantle heterogeneities, and investigate the integration of new constraints and novel interpretations from the combined perspective of multiple disciplines to better understand the nature and origin of mantle heterogeneities. We invite new results covering heterogeneities from the uppermost to the lowermost mantle from seismology, geodynamics, plate reconstruction, geochemistry, and mineral physics. Attempts to integrate these new results are welcome as well.<div><br></div></body></html>