HR: 0830h
AN: S21E-0368    [PDF]
TI: The Elastic Constants of Monoclinic Diopside at High Temperature
AU: * Isaak, D G
EM: disaak@apu.edu
AF: IGPP, UCLA, 405 Hilgard Avenue, Los Angeles, CA 90095-1567 United States
AU: Ohno, I
EM: ohno@sci.ehime-u.ac.jp
AF: Department of Earth Science, Ehime University, Bunkyo-cho,, Matsuyama Japan
AU: Lee, P
EM: a2312340@hotmail.com
AF: Department of Mathematics and Physics, Azusa Pacific University, Azusa, CA 91702-7000 United States
AB: Knowledge of the elastic properties of all candidate mantle minerals and how these properties vary with temperature and pressure is required to accurately describe the composition and structure of Earth's upper and lower mantle. It is generally believed that the four dominant minerals of Earth's upper mantle are olivine, orthopyroxene, clinopyroxene, and pyrope garnet, even though different compositional models ascribe varying amounts of these four minerals to the upper mantle. Olivine has received the most experimental attention, in part, because it is considered by most investigators to be the most abundant mineral of Earth's upper mantle. Conversely, clinopyroxene has received relatively little experimental attention even though 15-25 percent of the upper mantle likely consists of a clinopyroxene component. Indeed, there are no available data on the temperature dependences of the elastic constants of any single-crystal monoclinic clinopyroxene material. New resonant ultrasound spectroscopy (RUS) data on the temperature dependences of elasticity for a high quality single-crystal diopside specimen are presented. We measured and identified 38 of the 62 lowest modal frequencies from room temperature to 1300 K in order to determine the 13 elastic constants of monoclinic diopside over that temperature range. The temperature dependences of the bulk and shear moduli of diopside, calculated from the single-crystal data, are also discussed and are compared with other pyroxene results.
DE: 3909 Elasticity and anelasticity
DE: 3919 Equations of state
DE: 3939 Physical thermodynamics
DE: 7218 Lithosphere and upper mantle
SC: Seismology [S]
MN: 2003 Fall Meeting