September 7, 2016 - Jessica M Warren

Olivine anisotropy suggests Gutenberg discontinuity is not the base of the lithosphere

In an open access article published in the Proceedings of the National Academy of Sciences, Lars Hansen, Jessica Warren, and Chao Qi use experiments on olivine aggregates to show that the base of the lithosphere is best represented by thermal models that predict a gradational boundary. The deformation experiments indicate that changes in seismic anisotropy can be matched by the differences in olivine lattice preferred orientation as a function of the melt fraction present during mantle flow. Hence, seismic observations of a flat base to the lithosphere are interpreted as features frozen into the lithosphere during its creation at mid-ocean ridges.

Hansen, L.N., C. Qi, and J.M. Warren, 2016. Olivine torsion experiments constrain the nature of the oceanic lithosphere-asthenosphere boundary, Proceedings of the National Academy of Sciences, doi:10.1073/pnas.1608269113.