Fig. 31
From: The Atlantis Bank Gabbro Massif, Southwest Indian Ridge
Selected samples collected on Shinkai 6500 Dive 653 on the 57° 21′ E Fault Face (Fig. 29c). a Heavily fractured, chloritized, greenschist facies diabase in contact with talc-serpentine schist from the fault gouge at the lip of the bench above the high-angle normal fault at 57° 22′ E. Note “blackwall” zone in the dike margin due to reaction with the enclosing sheared serpentinite. Apparent boudinage of the diabase may actually reflect the development of a dike-finger structure due to melt intrusion approximately perpendicular to the cut face of the sample through sheared serpentinite. b Polymict cataclasite with coarse gabbro and diabase clasts in a fine-grained matrix from detachment fault footwall on the bench above the normal fault. Note the thin 1–3 mm manganese crust on the upper side of the sample
