HR: 0800h
AN: P41A-0191    [Abstracts]
TI: Phase Transition Evolution and Convection Style in the Martian Mantle
AU: * Ruedas, T
EM: ruedas@dtm.ciw.edu
AF: Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Rd, Washington, DC 20015, United States
AU: Tackley, P J
EM: ptackley@ethz.ch
AF: Institut für Geophysik, ETH Zürich, HPP L13 Schafmattstr.30, Zurich, 8093, Switzerland
AB: The higher iron content of the Martian mantle as compared to Earth's mantle results in a mineralogy and phase transition pattern which is somewhat different to that of the Earth; for instance, ringwoodite appears already at lower pressures than wadsleyite. Moreover, the two-phase loops in the Mg₂SiO₄--Fe₂SiO₄ system are broader and their position and width seem to be more sensitive to changes in temperature. Another concern is the uncertainty about the depth of the core--mantle boundary in Mars, which happens to lie at about the depth of the ringwoodite-(perovskite+magnesiowüstite) transition. Previous studies have already demonstrated the possibility that Mars had a perovskite layer at the base of its mantle which may have disappeared during the history of the planet as a consequence of secular cooling. In our study, we attempt to model the evolution of the phase transition patterns, i.e. the changes in position and width of transitions and the mineralogical changes, as a consequence of secular cooling and discuss their effect on the long-term convection style of the martian mantle.
DE: 0545 Modeling (4255)
DE: 5430 Interiors (8147)
SC: Planetary Sciences [P]
MN: 2007 Fall Meeting