TY - JOUR
T1 - In situ measurements of sound velocities and densities across the orthopyroxene ρarr; high-pressure clinopyroxene transition in MgSiO3 at high pressure
AU - Kung, Jennifer
AU - Li, Baosheng
AU - Uchida, Takeyuki
AU - Wang, Yanbin
AU - Neuville, Daniel
AU - Liebermann, Robert C.
N1 - Funding Information:
We thank for the support of beamline 13-ID, GSECARS, and, especially, M. Rivers and S. Sutton for their role in developing large-volume high-pressure facility. We also thank J. Hu, H. Liu and Z. Liu for assistance in conducting in situ X-ray DAC experiment on beamline X17C and Raman study on beamline U2A at National Synchrotron Light Source (NSLS). We are grateful to J. Jackson for providing the preprint of paper. We also would like to thank R. Angel, D. Mao and J. Parise for useful discussions. This study is supported by the National Science Foundation under the Grants EAR0229704 to R.C.L. and EAR0003340 to B.L.. Use of the Advanced Photon Source was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38. GSECARS is supported by the National Science Foundation – Earth Sciences, Department of Energy – Geosciences, W.M. Keck Foundation, and the U.S. Department of Agriculture. MPI publication no. 348.
PY - 2004/10/15
Y1 - 2004/10/15
N2 - Using acoustic measurement interfaced with a large volume multi-anvil apparatus in conjunction with in situ X-radiation techniques, we are able to measure the density and elastic wave velocities (VP and VS) for both ortho- and high-pressure clino-MgSiO3 polymorphs in the same experimental run. The elastic bulk and shear moduli of the unquenchable high-pressure clinoenstatite phase were measured within its stability field for the first time. The measured density contrast associated with the phase transition OEN → HP-CEN is 2.6-2.9% in the pressure of 7-9 GPa, and the corresponding velocity jumps are 3-4% for P waves and 5-6% for S waves. The elastic moduli of the HP-CEN phase are KS=156.7(8) GPa, G = 98.5(4) GPa and their pressure derivatives are KS′=5.5(3) and G′ = 1.5(1) at a pressure of 6.5 GPa, room temperature. In addition, we observed anomalous elastic behavior in orthoenstatite at pressure above 9 GPa at room temperature. Both elastic wave velocities exhibited softening between 9 and 13-14 GPa, which we suggest is associated with a transition to a metastable phase intermediate between OEN and HP-CEN.
AB - Using acoustic measurement interfaced with a large volume multi-anvil apparatus in conjunction with in situ X-radiation techniques, we are able to measure the density and elastic wave velocities (VP and VS) for both ortho- and high-pressure clino-MgSiO3 polymorphs in the same experimental run. The elastic bulk and shear moduli of the unquenchable high-pressure clinoenstatite phase were measured within its stability field for the first time. The measured density contrast associated with the phase transition OEN → HP-CEN is 2.6-2.9% in the pressure of 7-9 GPa, and the corresponding velocity jumps are 3-4% for P waves and 5-6% for S waves. The elastic moduli of the HP-CEN phase are KS=156.7(8) GPa, G = 98.5(4) GPa and their pressure derivatives are KS′=5.5(3) and G′ = 1.5(1) at a pressure of 6.5 GPa, room temperature. In addition, we observed anomalous elastic behavior in orthoenstatite at pressure above 9 GPa at room temperature. Both elastic wave velocities exhibited softening between 9 and 13-14 GPa, which we suggest is associated with a transition to a metastable phase intermediate between OEN and HP-CEN.
UR - http://www.scopus.com/inward/record.url?scp=4544305563&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=4544305563&partnerID=8YFLogxK
U2 - 10.1016/j.pepi.2004.05.008
DO - 10.1016/j.pepi.2004.05.008
M3 - Article
AN - SCOPUS:4544305563
SN - 0031-9201
VL - 147
SP - 27
EP - 44
JO - Physics of the Earth and Planetary Interiors
JF - Physics of the Earth and Planetary Interiors
IS - 1
ER -