HR: 0800h
AN: P31A-0956    [Abstracts]
TI: Experimental Study of "Dirty" Ice Systems: Implications for Ganymede and Callisto
AU: * Frank, M R
EM: mfrank@niu.edu
AF: Department of Geology and Environmental Geosciences, Northern Illinois University Davis Hall 312, Normal Rd., DeKalb, IL 60115 United States
AU: Runge, C
EM: crunge@princeton.edu
AF: Department of Geology, College of William and Mary P.O. Box 8795, Williamsburg, VA 23187 United States
AU: Maglio, S
EM: keyser.soze83@comcast.net
AF: Department of Geology and Environmental Geosciences, Northern Illinois University Davis Hall 312, Normal Rd., DeKalb, IL 60115 United States
AU: Olson, J
EM: stinkeetoe5@yahoo.com
AF: Department of Geology and Environmental Geosciences, Northern Illinois University Davis Hall 312, Normal Rd., DeKalb, IL 60115 United States
AU: Scott, H P
EM: hpscott@iusb.edu
AF: Dept. of Physics and Astronomy, Indiana University South Bend 345 Northside Hall, South Bend, IN 46634 United States
AB: Recent studies have hypothesized that high-pressure H$_{2}$O polymorphs, specifically Ice VI and Ice VII, make up a significant portion of the interiors of both Ganymede and Callisto. Several of Jupiter's satellites have been conjectured to contain subsurface salty H$_{2}$O waters; therefore, any potential "warm" ice phases in the interior of these satellites could have interacted extensively with the salty oceans. Raman spectroscopy and synchrotron radiation has been used previously to study the bonding structure and unit cell parameters of pure Ice VII. However, no data exists on the effect of salts on the unit cell parameters and volume of solid H$_{2}$O at high pressure. To obtain more realistic data for use in planetary physics, it is important to understand the effect of impurities on H$_{2}$O at high pressure. This study measured the unit cell volumes of Ice VII formed from a 5 wt.% NaCl-H$_{2}$O solution up to 25 GPa and 800 K by using a hydrothermal diamond anvil cell and synchrotron X-ray radiation. The experiments were conducted at the GSECARS 13-BM-D beamline (Advanced Photon Source), using monochromatic X-ray radiation and an online imaging system. The diffraction data indicate that the Ice VII formed from a 5 wt.% NaCl-H$_{2}$O solution has a molar density that is systematically increased at any given pressure relative to the molar density of Ice VII formed from pure H$_{2}$O. A zero-pressure volume, bulk modulus, and pressure derivative were calculated from this data and compared with pure Ice VII data reported by others. Thermal expansivity data of the Ice VII formed from the 5 wt.% NaCl-H$_{2}$O solution will also be presented up to 21 GPa. The inclusion of NaCl into Ice VII also acts to decrease systematically the melting curve of Ice VII. The new data can be used to model the density profiles of H$_{2}$O-rich bodies.
DE: 3672 Planetary mineralogy and petrology (5410)
DE: 3919 Equations of state
DE: 3954 X ray, neutron, and electron spectroscopy and diffraction
DE: 1060 Planetary geochemistry (5405, 5410, 5704, 5709, 6005, 6008)
DE: 1010 Chemical evolution
SC: Planetary Sciences [P]
MN: 2004 AGU Fall Meeting