Figure F30. Thin section image of a hybrid rock, Hole U1349A (Thin Section 222; Sample 324-U1349A-10R-3, 97–99 cm). Ophimottled rock with variable amounts of olivine is at the upper right and lower left. A diagonal band ~0.5 cm wide crosses the section. White veins are calcite. The band of fine-grained basalt has scattered altered olivine but no plagioclase-clinopyroxene intergrowths. Since all portions of the rock had virtually the same cooling rate, yet the crystals within the diagonal band are finer grained, it had the higher liquidus temperature, thus crystals within it were more greatly undercooled as they grew and are smaller.
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