Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: An experimental test of the viscous anisotropy hypothesis for partially
  molten rocks   Chemical differentiation of rocky planets occurs by melt segregation away
from the region of melting. The mechanics of this process, however, are complex
and incompletely understood. In partially molten rocks undergoing shear
deformation, melt pockets between grains align coherently in the stress field;
it has been hypothesized that this anisotropy in microstructure creates an
anisotropy in the viscosity of the aggregate. With the inclusion of anisotropic
viscosity, continuum, two-phase-flow models reproduce the emergence and angle
of melt-enriched bands that form in laboratory experiments. In the same
theoretical context, these models also predict sample-scale melt migration due
to a gradient in shear stress. Under torsional deformation, melt is expected to
segregate radially inward. Here we present new torsional deformation
experiments on partially molten rocks that test this prediction.
Microstructural analyses of the distribution of melt and solid reveal a radial
gradient in melt fraction, with more melt toward the centre of the cylinder.
The extent of this radial melt segregation grows with progressive strain,
consistent with theory. The agreement between theoretical prediction and
experimental observation provides a validation of this theory, which is
critical to understanding the large-scale geodynamic and geochemical evolution
of Earth.

27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
29
The categories of this paper are: funct-an
2
The categories of this paper are: math
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
19
The categories of this paper are: eess
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol