Plate 4. Selected key textural relationships in the pelitic and migmatite gneiss. 1. Leucosome domain of a migmatite gneiss formed by cordierite (Cd) interfingered with K-feldspar (K), plagioclase, biotite (b), and quartz. Sample 161-976B-98R-1, 96-101 cm. Plane-polarized light. Scale bar is 500 µm. 2. Decussate clusters of biotite (b) in leucosome domain, with abundant inclusions of elongated magnetite and Ti-magnetite grains. Sample 161-976B-98R-1, 96-101 cm. Plane-polarized light. Scale bar is 200 µm. 3. Rounded andalusite porphyroblasts (A) included with disharmonious fibrolitic sillimanite (S) in a large K-feldspar phenocryst (K). Sample 161-976B-101R-2, 38-41 cm. Plane-polarized light. Scale bar is 200 µm. 4. Idiomorphic and zoned andalusite phenocrysts included in a large K-feldspar grain (K). Sample 161-976B-96R-1, 46-48 cm. Cross-polarized light. Scale bar is 500 µm. 5. Mutual intergrowths between cordierite (Cd) and the granitic matrix, composed by K-feldspar (K), quartz, and minor plagioclase phenocrysts. Sample 161-976B-96R-1, 46-48 cm. Plane-polarized light. Scale bar is 500 µm. 6. Andalusite porphyroblasts (A) included in a large cordierite grain (Cd), partially retrograded to pinnite. Sample 161-976B-96R-1, 46-48 cm. Plane-polarized light. Scale bar is 500 µm.

Plate 4. Selected key textural relationships in the pelitic and migmatite gneiss. 1. Leucosome domain of a migmatite gneiss formed by cordierite (Cd) interfingered with K-feldspar (K), plagioclase, biotite (b), and quartz. Sample 161-976B-98R-1, 96-101 cm. Plane-polarized light. Scale bar is 500 µm. 2. Decussate clusters of biotite (b) in leucosome domain, with abundant inclusions of elongated magnetite and Ti-magnetite grains. Sample 161-976B-98R-1, 96-101 cm. Plane-polarized light. Scale bar is 200 µm. 3. Rounded andalusite porphyroblasts (A) included with disharmonious fibrolitic sillimanite (S) in a large K-feldspar phenocryst (K). Sample 161-976B-101R-2, 38-41 cm. Plane-polarized light. Scale bar is 200 µm. 4. Idiomorphic and zoned andalusite phenocrysts included in a large K-feldspar grain (K). Sample 161-976B-96R-1, 46-48 cm. Cross-polarized light. Scale bar is 500 µm. 5. Mutual intergrowths between cordierite (Cd) and the granitic matrix, composed by K-feldspar (K), quartz, and minor plagioclase phenocrysts. Sample 161-976B-96R-1, 46-48 cm. Plane-polarized light. Scale bar is 500 µm. 6. Andalusite porphyroblasts (A) included in a large cordierite grain (Cd), partially retrograded to pinnite. Sample 161-976B-96R-1, 46-48 cm. Plane-polarized light. Scale bar is 500 µm. Click on image for enlargement.