Experimental test of the viscous anisotropy hypothesis for partially molten rocks

@article{Qi2015ExperimentalTO,
  title={Experimental test of the viscous anisotropy hypothesis for partially molten rocks},
  author={Chao Qi and David L. Kohlstedt and Richard F. Katz and Yasuko Takei},
  journal={Proceedings of the National Academy of Sciences},
  year={2015},
  volume={112},
  pages={12616 - 12620}
}
Significance Partially molten regions of Earth link mantle convection with surface volcanism. We present laboratory experiments and theory that are at the heart of understanding the connection between these interior and surface processes. The theory proposes that the presence of melt fundamentally changes the style of deformation, making it anisotropic with leading-order, testable consequences. The laboratory results are in agreement with theoretical predictions. These results are novel at a… 

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References

SHOWING 1-10 OF 31 REFERENCES

RHEOLOGY OF PARTIALLY MOLTEN MANTLE ROCKS

▪ Abstract Over the past decade, significant progress has been made in understanding the rheological properties of partially molten mantle rocks. Laboratory experiments demonstrate that a few percent

The dynamics of melt and shear localization in partially molten aggregates

This work test a formulation for magma dynamics and provides an explanation for localized bands of high-porosity and concentrated shear deformation observed in experiments, and estimates the orientation of melt bands beneath mid-ocean ridges and shows that they may enhance magma focusing toward the ridge axis.

Shearing Melt Out of the Earth: An Experimentalist's Perspective on the Influence of Deformation on Melt Extraction

Melt extraction from the Earth's mantle requires some form of channelized flow to produce the observed disequilibrium between the crust-forming lavas and their mantle sources. In this review, we

Stress-driven Melt Segregation in Partially Molten Olivine-rich Rocks Deformed in Torsion

Torsion experiments on partially molten aggregates of olivine þ chromite þ 4 vol. % mid-ocean ridge basalt provide new insights into the interactions between deformation and melt segregation. When

Viscous constitutive relations of solid‐liquid composites in terms of grain boundary contiguity: 3. Causes and consequences of viscous anisotropy

[1] The viscous constitutive relations of partially molten rocks developed here show that an anisotropy in grain-scale melt distribution can lead to a strong anisotropy in the viscosity of the solid

Stress‐driven melt segregation in partially molten rocks

We demonstrate that deformation of partially molten ductile rocks can produce melt segregation by two‐phase flow. In simple shear experiments on several melt‐rock systems at high temperature and

Consequences of viscous anisotropy in a deforming, two-phase aggregate. Part 1. Governing equations and linearized analysis

Abstract In partially molten regions of Earth, rock and magma coexist as a two-phase aggregate in which the solid grains of rock form a viscously deformable framework or matrix. Liquid magma resides

Rheology and structure of olivine‐basalt partial melts

Recent experiments demonstrate that solution-precipitation (pressure-solution) processes in the liquid basalt-olivine system are exceedingly rapid. The effect of liquid basalt on the diffusional