Figure F11. Chemical map showing variations in Al in a plagioclase-rich vein (Sample 176-735B-120R-2, 99-104 cm). The vein margin on the right side (delineated by solid black line) is marked by a significant change in plagioclase composition from calcic plagioclase (An) in the host rock to more sodic plagioclase (Pl) in the vein. Large, subhedral, zoned plagioclase crystals are concentrated along the vein wall. The low-Al zone (blue color) in the center of the vein consists of dark aphanitic material. Note the rim of chlorite on the large clinopyroxene grain (red color) in the upper right corner. Scale bar = 5 mm. Ap = apatite.

Figure F11. Chemical map showing variations in Al in a plagioclase-rich vein (Sample 176-735B-120R-2, 99-104 cm). The vein margin on the right side (delineated by solid black line) is marked by a significant change in plagioclase composition from calcic plagioclase (An) in the host rock to more sodic plagioclase (Pl) in the vein. Large, subhedral, zoned plagioclase crystals are concentrated along the vein wall. The low-Al zone (blue color) in the center of the vein consists of dark aphanitic material. Note the rim of chlorite on the large clinopyroxene grain (red color) in the upper right corner. Scale bar = 5 mm. Ap = apatite.