Major element zoning in the garnets is overall concentric in garnets with and without misorientations. Mn decreases from the petrographic center of the garnets to the rim. Although the overall zoning pattern crosscuts lattice boundaries, there are very minor changes in Mn across the boundaries, with slightly lower Mn contents (< 2.5 mol% Sps) along the boundary. The distribution of Mn corresponds spatially to the location of quartz and plagioclase inclusions (lower Mn near inclusions), and does not outline distinct garnet lattice orientations. Also, in a garnet with 3 different orientations, one lattice zone corresponds to a low-Mn garnet rim region.
Our data rule out post-crystallization deformation as a cause of the misorientations. However, because there is no obvious relationship between Mn-zoning and lattice misorientations, the presence of Mn-zoning across the misorientation boundaries is not sufficient evidence to prove that such misorientations are the result of coalescencing high-Mn nuclei. The garnets may have formed from several nuclei that formed at different times in the metamorphic history of the rock, but the mechanism of attachment and continued growth remains a question.