Figure F29. In the brown halos surrounding miarolitic cavities, the wall-rock basalt is completely replaced by smectite (brown to tan), calcite (white), and minor goethite (black) in Sample 192-1187A-5R-4 (Piece 5, 91-94 cm) (field of view = 1.4 mm; plane-polarized light; photomicrograph ID# 1187A

Figure F29. In the brown halos surrounding miarolitic cavities, the wall-rock basalt is completely replaced by smectite (brown to tan), calcite (white), and minor goethite (black) in Sample 192-1187A-5R-4 (Piece 5, 91-94 cm) (field of view = 1.4 mm; plane-polarized light; photomicrograph ID# 1187A_260).