Figure F17. Core photograph and thin section photomicrographs from Core 205-1253A-17R, in the upper part of Subunit 4B. A. 4-mm-wide vein with glassy margin and zeolite filling (Sample 205-1253A-17R-2, 100–117 cm). B. Photomicrograph in cross-polarized light (XPL) taken with a blue filter at 5x magnification, showing microcrystalline gabbro (Sample 205-1253A-17R-2, 108–111 cm). C. Photomicrograph showing zeolites, probably mesolite or thomsonite (thin section 27-E; Sample 205-1253A-17R-2, 108–111 cm; 478.18 mbsf). Cpx = clinopyroxene, Pl = plagioclase.