Figure F5. Compositions of gabbros plotted against depth. A. Mg# = Mg/(Mg + Fe2+), where Fe2+/[Fe2+/(Fe2+ + Fe3+)] = 0.85 (Natland et al., 1991). B. TiO2 (%), log units. Open squares = oxide gabbros (>1% TiO2), half-solid squares = tonalite, trondhjemite, and diorite (>54% and up to 70% SiO2), solid blue circles = differentiated gabbros, including disseminated oxide gabbros (<54% SiO2 and Mg# [=100 x Mg/(Mg + Fe2+)] < 72.5), solid red circles = olivine gabbros (are the same, but with Mg# > 72.5 and up to MgO = 12%), solid black circles = troctolitic gabbros plus troctolites (>12% MgO), solid triangles = Olivine pyroxenites (like troctolites, but with normative Di > 40%). Horizontal lines delineate boundaries between series, which are indicated by number. The placements of two lithologic units (IV and V) are also indicated.

Figure F5. Compositions of gabbros plotted against depth. A. Mg# = Mg/(Mg + Fe²⁺), where Fe²⁺/[Fe²⁺/(Fe²⁺ + Fe³⁺)] = 0.85 (Natland et al., 1991). B. TiO₂ (%), log units. Open squares = oxide gabbros (>1% TiO₂), half-solid squares = tonalite, trondhjemite, and diorite (>54% and up to 70% SiO₂), solid blue circles = differentiated gabbros, including disseminated oxide gabbros (<54% SiO₂ and Mg# [=100 x Mg/(Mg + Fe²⁺)] < 72.5), solid red circles = olivine gabbros (are the same, but with Mg# > 72.5 and up to MgO = 12%), solid black circles = troctolitic gabbros plus troctolites (>12% MgO), solid triangles = Olivine pyroxenites (like troctolites, but with normative Di > 40%). Horizontal lines delineate boundaries between series, which are indicated by number. The placements of two lithologic units (IV and V) are also indicated.