Figure F25. Main alteration feature in Units 4, 5, and 6. A. Sample 203-1243B-8R-2, 25-29 cm (PPL; field of view = 2.75 mm; photomicrograph 1243B-15). B. Sample 203-1243B-7R-3, 20-23 cm (PPL; field of view = 2.75 mm; photomicrograph 1243B-24). C. Sample 203-1243B-9R-2, 138-141 cm (PPL; field of view = 2.75 mm; photomicrograph 1243B-34).