Figure F16. Core photograph and thin section photomicrographs from Subunit 4A. A. Close-up photograph of microcrystalline to fine-grained homogeneous holocrystalline gabbro (interval 205-1253A-8R-2 [Piece 2, 45–60 cm]). B. Microcrystalline gabbro observed within Subunit 4A. C. Completely altered primary mineral, replaced by clay (thin section 10-A; Sample 205-1253A-7R-1, 130–133 cm; 414.6 mbsf). D. Olivine, completely altered to clay (thin section 13-C; Sample 205-1253A-8R-1, 24–27 cm; 416.24 mbsf). E. Olivine, mostly replaced by clay (thin section 13-D; Sample 205-1253A-8R-1, 24–27cm; 416.24 mbsf). F.ŻAltered plagioclase, replaced by a mixture of clay and isotropic secondary products (thin section 13-E; Sample 205-1253A-8R-1, 24–27 cm; 416.24 mbsf). Mag = magnetite, Pl = plagioclase, Ilm = ilmenite, Ol = olivine.