Figure F27. Photomicrographs showing olivine replaced by a fine-grained amphibole, chlorite, and minor sericite. The former olivine grain boundaries, outlined by rims of magnetite (arrows), are still recognizable (Sample 209-1271B-13R-1, 20–24 cm). A. Plane-polarized light: blue filter; field of view = 2.75 mm; image 1271B_051). B. Cross-polarized light: blue filter; field of view = 2.75 mm; image 1271B

Figure F27. Photomicrographs showing olivine replaced by a fine-grained amphibole, chlorite, and minor sericite. The former olivine grain boundaries, outlined by rims of magnetite (arrows), are still recognizable (Sample 209-1271B-13R-1, 20–24 cm). A. Plane-polarized light: blue filter; field of view = 2.75 mm; image 1271B_051). B. Cross-polarized light: blue filter; field of view = 2.75 mm; image 1271B_052.