The anisotropic signal of topotaxy during phase transitions in D′′

Andrew Walker, David P Dobson, James Wookey, Andy Nowacki, Alessandro M Forte

Research output: Contribution to journalArticle (Academic Journal)peer-review

10 Citations (Scopus)
311 Downloads (Pure)


While observations and modelling of seismic anisotropy in the lowermost mantle offers the possibility of imaging mantle flow close to the core-mantle boundary, current models do not explain all observations. Here, we seek to explain a long-wavelength pattern of shear wave anisotropy observed in anisotropic tomography where vertically polarised shear waves travel faster than horizontally polarised shear waves in the central Pacific and under Africa but this pattern is reversed elsewhere. In particular, we test an explanation derived from experiments on analogues, which suggest that texture may be inherited during phase transitions between bridgmanite (perovskite structured MgSiO3) and post-perovskite, and that such texture inheritance may yield the long-wavelength pattern of anisotropy. We find that models that include this effect correlate better with tomographic models than those that assume deformation due to a single phase in the lowermost mantle, supporting the idea that texture inheritance is an important factor in understanding lowermost mantle anisotropy. It is possible that anisotropy could be used to map the postperovskite stability field in the lowermost mantle, and thus place constraints on the temperature structure above the core-mantle boundary.
Original languageEnglish
Number of pages13
JournalPhysics of the Earth and Planetary Interiors
Early online date15 May 2017
Publication statusE-pub ahead of print - 15 May 2017

Bibliographical note

Document is AAM not pre-print - template used.


  • Post-perovskite
  • Seismic anisotropy
  • Lowermost mantle
  • Phase transition
  • Mantle convection


Dive into the research topics of 'The anisotropic signal of topotaxy during phase transitions in D′′'. Together they form a unique fingerprint.

Cite this