HR: 0800h
AN: P41A-0190    [Abstracts]
TI: Investigation of the Effects of H2O on Melting of a Primitive Martian Mantle Composition
AU: * Dalton, H A
EM: heather.a.dalton@rice.edu
AF: Department of Earth Science Rice University, MS 126 PO Box 1892, Houston, TX 77251-1892, United States
AU: Holloway, J R
EM: john.holloway@asu.edu
AF: School of Earth and Space Exploration Arizona State University, Box 871404, Tempe, AZ 85287-1404, United States
AU: Sharp, T G
EM: tom.sharp@asu.edu
AF: School of Earth and Space Exploration Arizona State University, Box 871404, Tempe, AZ 85287-1404, United States
AU: Hervig, R L
EM: hervig@asu.edu
AF: School of Earth and Space Exploration Arizona State University, Box 871404, Tempe, AZ 85287-1404, United States
AB: Extensive signs of past water exist on the Martian surface. While many experiments have been performed on hydrated terrestrial compositions, it is only recently that such experiments have been applied to Mars. High- pressure experiments were performed in a piston cylinder apparatus using a synthetic composition of Martian meteorite Yamato 980459, with 0.5 weight percent H₂O added. This composition was chosen because it is a very primitive meteorite, and experiments suggest that it may represent a primary melt of the Martian mantle. The addition of 0.5 weight percent H₂O lowered the liquidus temperature and decreased the slope of the liquidus slightly. Four phase assemblages were observed: 1) liquid, 2) olivine + liquid, 3) olivine + orthopyroxene + liquid, and 4) orthopyroxene + pigeonite + liquid. The multiple saturation point could exist at a higher pressure than the anhydrous experiments, indicating a hydrated Yamato 980459-type melt could form deeper within the Martian mantle.
DE: 5430 Interiors (8147)
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: 2007 Fall Meeting