HR: 0800h
AN: T41B-1177    [Abstracts]
TI: The Phase Diagram of Talc, 10A phase and 3.64A Phase.
AU: * Clark, S M
EM: smclark@lbl.gov
AF: Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 United States
AU: * Clark, S M
EM: smclark@lbl.gov
AF: Department of Earth Sciences The University of Manchester, Oxford Road, Manchester, M13 9PL United Kingdom
AU: Gleason, A E
EM: AEGleason@lbl.gov
AF: Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 United States
AU: Pawley, A R
EM: alison.pawley@man.ac.uk
AF: Department of Earth Sciences The University of Manchester, Oxford Road, Manchester, M13 9PL United Kingdom
AU: Parry, S
EM: steve_007_21@yahoo.com
AF: Department of Earth Sciences The University of Manchester, Oxford Road, Manchester, M13 9PL United Kingdom
AU: Walter, M J
EM: M.J.Walter@bristol.ac.uk
AF: Department of Earth Sciences University of Bristol, Wills Memorial Building Queens Road, Bristol, BS8 1RJ United Kingdom
AB: The pressure-volume phase diagram for the Talc (Mg$_{3}$Si$_{4}$O$_{10}$(OH)$_{2}$), 10A phase (Mg$_{3}$Si$_{4}$O$_{10}$(OH)$_{2}$ xH$_{2}$O), 3.65A phase system has been determined using laboratory x-ray diffraction from quenched samples from a multianvil high-pressure cell and synchrotron x-ray diffraction from samples held in resistively heated diamond anvil cells. The talc data best fit a triclinic crystal structure while the 10A phase data can be fitted to a trioctahedral mica model structure. Details of the experimental techniques, phase diagram and implications for water transport into the upper mantle following subduction will be presented.
DE: 8120 Dynamics of lithosphere and mantle--general
DE: 8124 Earth's interior--composition and state (old 8105)
DE: 3924 High-pressure behavior
DE: 3954 X ray, neutron, and electron spectroscopy and diffraction
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting