Figure F284 (continued). D. Highly altered, recrystallized dark gray fine grained aphyric basalt (Unit 1256D-90a) intruded by highly to completely altered heterogeneous dark gray to dark greenish gray gabbro (Unit 1256D-91a; interval 312-1256D-230R-1 [Pieces 5 and 6, 15–33 cm]). The upper edge of the gabbro intrusion is completely altered to secondary feldspar + epidote + amphibole + chlorite. The basalt dike is baked and has a 5 mm very dark gray alteration halo along the margin with the gabbro intrusion; alteration is less intense in the host dike adjacent to the 1 cm wide subhorizontal gabbro apophysis at the top of Piece 5. A completely altered and comminuted 40 mm chloritic band runs diagonally through the highly altered gabbro in Piece 6 parallel to the basalt/gabbro contact. The gabbro includes many dike clasts with diffuse (corroded?) margins. E. Large (~10 mm) quartz + epidote + actinolitic hornblende vein with an intense 10 mm dark green inner and 50 mm light gray outer alteration halo in a medium-grained olivine-orthopyroxene-bearing oxide gabbro (Unit 1256D-88; interval 312-1256D-220R-1, 93–108 cm). F. Thin dikelet of medium-grained leucogabbro (Unit 1256D-91b) intrudes medium grained gabbro (Unit 1256D-91a; interval 312-1256D-230R-1, 117–132 cm). Leucogabbro has a sutured contact with the host gabbro but is highly altered to actinolitic hornblende and white secondary feldspar. Dike has a 5 mm dark green chloritic halo in the host gabbro. The gabbro includes many dike clasts from Unit 1256D-90a, with diffuse (corroded?) margins. A 1.5 mm quartz + chlorite vein with a 1 mm dark green chloritic halo postdates the intrusion of Unit 1256D-91b into Unit 1256D-91a. Scale is the same for all photographs.
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