Figure 9. Field photographs and photomicrographs of picritic and high-MgO basalt lavas in the Karmutsen Range, northern Vancouver Island. (a) Massive submarine flow (marked with arrows) draped over high-MgO pillow basalt of similar composition. (b) Picritic pillow basalts in cross-section. Note vesicular upper margin to pillows (sledgehammer for scale). (c) Photomicrograph of Keogh Lake picrite with abundant (up to 42 vol %) euhedral olivine pseudomorphs (<2 mm) in XPL, from the type locality near Keogh Lake (sample has 19-19.8 wt % MgO, 4 analyses). The groundmass is acicular plagioclase intergrown with clinopyroxene and altered glass. In many cases, plagioclase in the picrites nucleated on the edges of the olivine phenocrysts. (d) Sheaves of intergrown plagioclase and clinopyroxene in aphyric high-MgO basalt pillow lava in XPL from the Karmutsen Range (sample has 10.8 wt % MgO). The scale bars in panels c and d are 1 mm long. See discussion of picrites in Greene et al. (2006; 2008c).