Figure F69. A. Highly vesicular glass fragment in which vesicles are completely filled with brown smectite in Sample 192-1184A-45R-6, 82-85 cm. The glass fragment (lower left) shows "fibril-like" features protruding into the fresh glass from the altered margin, possibly related to microbially mediated alteration (field of view = 2.8 mm; plane-polarized light; photomicrograph ID# 1184A_150). B. Close-up of Sample 192-1184A-45R-6, 82-85 cm, showing the highly vesicular glass fragment shown in (A) (field of view = 1.4 mm; plane-polarized light; photomicrograph ID# 1184A

Figure F69. A. Highly vesicular glass fragment in which vesicles are completely filled with brown smectite in Sample 192-1184A-45R-6, 82-85 cm. The glass fragment (lower left) shows "fibril-like" features protruding into the fresh glass from the altered margin, possibly related to microbially mediated alteration (field of view = 2.8 mm; plane-polarized light; photomicrograph ID# 1184A_150). B. Close-up of Sample 192-1184A-45R-6, 82-85 cm, showing the highly vesicular glass fragment shown in (A) (field of view = 1.4 mm; plane-polarized light; photomicrograph ID# 1184A_151).