Fig. 23

Examples of Atlantis Bank seafloor olivine gabbros selected from Dredge JCR31-12 from a landslip headwall at the northern end of the gabbro massif (Fig. 3). a Undeformed intergranular olivine gabbro with large centimeter-scale plagioclase laths. b Olivine troctolitic-equigranular gabbro with orange clay replacing olivine on margins. c Equigranular olivine gabbro crosscut by a high-temperature (e.g., 600–1000 °C) protomylonite oxide gabbro imaged dry to enhance Fe-Ti oxides impregnating and replacing the silicate matrix of the undeformed olivine gabbro adjacent to the contact. d Equigranular olivine gabbro with a possible weakly deformed magmatic foliation grading from coarse- to medium-grained gabbro perpendicular to the foliation. e Unusually olivine-rich, troctolitic gabbro with dendritic-structured olivine intergrown with equigranular sub-millimeter-scale augite and plagioclase chadocrysts. f Olivine gabbro with characteristic sub-ophitic augite and intergranular plagioclase