Xenoliths of semipelitic rocks that show metamorphic segregation structures occur in the granitic rock at Rosguill. The commonest type is an intergrowth of cordierite, muscovite, microcline, and biotite surrounded by a mantle of microcline, and coarser at the center. Others consist of a fine-grained intergrowth of biotite and microcline mantled by coarse-grained material or large grains of microcline mantled by biotite. The segregations are mineralogically similar to the ground-mass and probably formed by differential transfer of material within a localized zone of the ground-mass.

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