Figure F43. Photomicrographs illustrating late brittle-ductile deformation and faulting in troctolitic gabbros and dunites. A. Amphibolite replacing troctolite(?) showing a large amphibole crystal that has been sheared to form numerous parallel subgrains (Am1), separated from a patch of secondary amphibole (Am2) by a late, chloritized microfault (Sample 209-1271B-17R-1 [Piece 3, 17–19 cm]) (cross-polarized light [XPL]: blue filter; field of view [FOV] = 5.5 mm; image 1271B_121). B. Microfault along which a coarse-grained amphibole has been sheared (upper left), with the development of a secondary fibrous amphibole-talc-chlorite (Tc – Am2 – Chl) assemblage in the shear zone (lower right) (Sample 209-1271B-17R-1, 17–19 cm) (XPL: blue filter; FOV = 5.5 mm; image 1271B_120). C. Fully developed secondary fibrous amphibole (Am2)-talc (Tc)-chlorite (chl) assemblage on a late shear zone (Sample 209-1271B-17R-1, 17–19 cm) (XPL: blue filter; FOV = 2.75 mm; image 1271_119). D. Amphibole (Am) veined dunite showing a sheared secondary amphibole vein that crosscuts earlier secondary amphibole (Sample 209-1271B-18R-1 [Piece 20, 114–117 cm]) (XPL; FOV = 5.5 mm; image 1271B

Figure F43. Photomicrographs illustrating late brittle-ductile deformation and faulting in troctolitic gabbros and dunites. A. Amphibolite replacing troctolite(?) showing a large amphibole crystal that has been sheared to form numerous parallel subgrains (Am₁), separated from a patch of secondary amphibole (Am₂) by a late, chloritized microfault (Sample 209-1271B-17R-1 [Piece 3, 17–19 cm]) (cross-polarized light [XPL]: blue filter; field of view [FOV] = 5.5 mm; image 1271B_121). B. Microfault along which a coarse-grained amphibole has been sheared (upper left), with the development of a secondary fibrous amphibole-talc-chlorite (Tc – Am₂ – Chl) assemblage in the shear zone (lower right) (Sample 209-1271B-17R-1, 17–19 cm) (XPL: blue filter; FOV = 5.5 mm; image 1271B_120). C. Fully developed secondary fibrous amphibole (Am₂)-talc (Tc)-chlorite (chl) assemblage on a late shear zone (Sample 209-1271B-17R-1, 17–19 cm) (XPL: blue filter; FOV = 2.75 mm; image 1271_119). D. Amphibole (Am) veined dunite showing a sheared secondary amphibole vein that crosscuts earlier secondary amphibole (Sample 209-1271B-18R-1 [Piece 20, 114–117 cm]) (XPL; FOV = 5.5 mm; image 1271B_128).