Single-crystal elasticity of the α and β of Mg2SiO4 polymorphs at high pressure

Chang Sheng Zha, Thomas S. Duffy, Robert T. Downs, Ho Kwang Mao, Russell J. Hemley, Donald J. Weidner

Research output: Chapter in Book/Report/Conference proceedingChapter

16 Scopus citations


The full set of single-crystal elastic moduli of forsterite (α-Mg2SiO4) and wadsleyite (β-Mg2SiO4) were measured at pressures of 3-16 GPa and 0-14 GPa, respectively. For forsterite, the pressure derivatives of the bulk (K0‘s) and shear (G0') modulus are 4.2 ± 0.2 and 1.4 ± 0.1, respectively. For wadsleyite, the corresponding pressure derivatives are 4.3 ± 0.2 and 1.4 ± 0.2. These values are much lower than those reported in earlier, low-pressure studies for both materials. At the pressure of the 410-km seismic discontinuity, the room-temperature velocity increase across the a-p transition is 9.8% for compressional waves and 12.4% for shear waves. The results are consistent with an olivine fraction in the upper mantle of 30-50%.

Original languageEnglish (US)
Title of host publicationProperties of Earth and Planetary Materials at High Pressure and Temperature, 1998
EditorsMurli H. Manghnani, Takehiko Yagi
PublisherBlackwell Publishing Ltd.
Number of pages8
ISBN (Electronic)9781118664421
ISBN (Print)9780875900834
StatePublished - 1997
Externally publishedYes

Publication series

NameGeophysical Monograph Series
ISSN (Print)0065-8448
ISSN (Electronic)2328-8779

All Science Journal Classification (ASJC) codes

  • Geophysics


Dive into the research topics of 'Single-crystal elasticity of the α and β of Mg2SiO4 polymorphs at high pressure'. Together they form a unique fingerprint.

Cite this