The migration of late-stage magmatic fractions along shear zones at seafloor spreading centers will modify bulk composition, temperature, and fluid chemistry, as well as pressure during deformation. These changes will influence the rheological evolution of oceanic shear zones and the time-dependent strength of the ocean crust. Yet, little is known about the role of these phases during shear-zone deformation, the mechanisms by which they deform, and the timing of melt migration relative to deformation.
Magnetite preserves no strong crystallographic preferred orientation in any of the samples.
Ilmenite deformed by dislocation creep in one sample and probably by diffusion creep in a second sample. In a third sample, primary textures may persist in both magnetite and ilmenite.