Figure F24. A. Photomicrograph of a strongly altered sandy siltstone from Unit II (thin section from Sample 195-1201D-17R-3, 106-108 cm [237.77 mbsf]) (plane-polarized light). The silty groundmass consists of devitrified (palagonitized) glass shards hosting "ghosts" of former detrital sand grains, which were pseudomorphically replaced by sparry zeolite. B. Photomicrograph showing details in a replaced sand grain (cross-polarized light).

Figure F24. A. Photomicrograph of a strongly altered sandy siltstone from Unit II (thin section from Sample 195-1201D-17R-3, 106-108 cm [237.77 mbsf]) (plane-polarized light). The silty groundmass consists of devitrified (palagonitized) glass shards hosting "ghosts" of former detrital sand grains, which were pseudomorphically replaced by sparry zeolite. B. Photomicrograph showing details in a replaced sand grain (cross-polarized light).