Figure F40. Some flow-banded clasts in Unit 20 show fine, wispy domains consisting of black, very fine grained material. Possibly, these bands consist of Fe oxides that filled stretched microvesicles during an early stage of alteration (Sample 193-1189B-13R-1 [Piece 4, 22-24 cm] in plane-polarized light; width of view = 1.38 mm. Photomicrograph ID# 1189B

Figure F40. Some flow-banded clasts in Unit 20 show fine, wispy domains consisting of black, very fine grained material. Possibly, these bands consist of Fe oxides that filled stretched microvesicles during an early stage of alteration (Sample 193-1189B-13R-1 [Piece 4, 22-24 cm] in plane-polarized light; width of view = 1.38 mm. Photomicrograph ID# 1189B_32; thin section 127).